cc @mc-hamster. In some cases storeForwardPluginRadio can be null ;-)
~/development/meshtastic/meshtastic-esp32$ bin/exception_decoder.py -e .pio/build/tbeam/firmware.elf ex
stack:
0x401db467: StoreForwardPluginRadio::sendPayload(unsigned int, bool) at /home/kevinh/development/meshtastic/meshtastic-esp32/src/plugins/esp32/StoreForwardPlugin.cpp:235
0x400e7cbd: StoreForwardPlugin::runOnce() at /home/kevinh/development/meshtastic/meshtastic-esp32/src/plugins/esp32/StoreForwardPlugin.cpp:225
0x400d4cca: concurrency::OSThread::run() at /home/kevinh/development/meshtastic/meshtastic-esp32/src/concurrency/OSThread.cpp:45
0x400f015d: ThreadController::runOrDelay() at /home/kevinh/development/meshtastic/meshtastic-esp32/.pio/libdeps/tbeam/Thread/ThreadController.cpp:153
0x400da070: loop() at /home/kevinh/development/meshtastic/meshtastic-esp32/src/main.cpp:621
0x400ff709: loopTask(void*) at /home/kevinh/.platformio/packages/framework-arduinoespressif32/cores/esp32/main.cpp:19
Signed-off-by: Kevin Hester <kevinh@geeksville.com>
Instead of holding onto only the last measurement, hold onto a copy of the last MeshPacket containing a measurement
This will make it easier to display the last time received
make DHT sensor reads more reliable
user preference for Farenheit vs Celsius
specifying a tag/commit/etc (I haven't tried specifying a branch?)
Without specifying the hash, the build breaks for anyone who already had
a repo (the CI build doesn't see this because it always pulls from scratch)
cc @crossan007 & @mc-hamster
@mc-hamster seems to work pretty good for me, so I'll send a PR to you
for the dev-http branch.
I'll push out an android alpha build later today (once the build is
complete). Once this new device load is out in the field _future_
device builds will support updating spiffs from android. (i.e. device
loads older than 1.1.9 must be updated to 1.1.9 or later before spiffs
support is implemented on the device side - so some users might need to
update twice before the new spiffs contents will appear on their device)
Typo fixed. I placed the latest javascript library files into the static folder. Updated the root file handler to be able to serve both compressed and uncompressed files.
+ // NOTE: The phone app needs to know the ls_secs value so it can properly expect sleep behavior.
+ // So even if we internally use 0 to represent 'use default' we still need to send the value we are
+ // using to the app (so that even old phone apps work with new device loads).
+#define MAX_POWER 27
// if we use 20 we are limited to 1% duty cycle or hw might overheat. For continuous operation set a limit of 17
+// In theory up to 27 dBm is possible, but the modules installed in most radios can cope with a max of 20. So BIG WARNING
+// if you set power to something higher than 17 or 20 you might fry your board.
Could cause hangs on the way into sleep (and enormous power consumption).
Instead of checking for rx packet length (which only changes at completion)
check if we've received preamble bits but haven't yet received a completed
packet interrupt.
notes:
wait to sleep loop problem
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
Can not send yet, busyRx
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
vs normal run
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
radio wait to sleep, txEmpty=0
Starting low level send (id=0x53fe1dd0 Fr0xe5 To0xff, WantAck0, HopLim3 encrypted)
Completed sending (id=0x53fe1dd0 Fr0xe5 To0xff, WantAck0, HopLim3 encrypted)
bogus wakes on TBEAMS because the USB->SERIAL chip pulls the RX input
to ground. This feature is no longer needed because in !isRouter
nodes we force the node to never sleep anyways when on USB power.
// this doesn't work on TBEAMs when the USB is depowered (causes bogus interrupts)
// So we disable this "wake on serial" feature - because now when a TBEAM (only) has power connected it
// never tries to go to sleep if the user is using the API
// gpio_wakeup_enable((gpio_num_t)SERIAL0_RX_GPIO, GPIO_INTR_LOW_LEVEL);
Sample usage:
First configure device to use @mc-hamster's new wifi stuff:
meshtastic --set wifi_ssid mylanname --set wifi_password mylanpassword
Then reboot the device (so wifi starts up).
(assuming device was assigned addr 192.168.81.45)
meshtastic --info --host 192.168.81.45
(See the usual device info you previously had to get over USB)
Caveats:
* Currently we are limiting to one active TCP connection open at once, if
you open a new session the old one is closed automatically
* There are no access controls/authentication needed to open a TCP
connection to the device
* Currently main.cpp is kinda dumb about how we should schedule work and
we rely on too many helper loop() functions. Very soon in my queue
(related to all the other cleanup) is to add a basic notion of coroutines,
so that we can get away from freertos threads and this old school arduino
loop function. Once that cleanup happens we can the a) have much lower
battery consumption (always) and b) super fast response for all operations.
btw - from my read of the NMEA, the lowest value that means 'has a valid
position' is 1 not 2. But I only know this because you pointed me at
it ;-)
Thanks!
oh - I think I found the problem (probably)! we were isolating gpio12 (which isn't used on other boards) to save power during sleep. gpio12 is the button for this board. @thomslik would you mind pulling this commit and seeing if it works better?
However, disabled until someone with suitable hardware can test and report
back.
@slavino and @tschundler would you be willing to try it with your boards?
You'll need to uncomment the following line in configuration.h
// #define BATTERY_PIN 35 // A battery voltage measurement pin, voltage divider connected here to measure battery voltage
@professr I noticed you added a "newStatus" observable to the GPS class.
Do you remember why you didn't remove the old GPS status (which seemed
to be dumber). Is it just because you didn't want to risk breaking
MeshService? (I assume) In this change I removed the old Observable
and all seems well (just using newStatus everywhere).
/**
* Generate a short suffix used to disambiguate channels that might have the same "name" entered by the human but different PSKs.
* The ideas is that the PSK changing should be visible to the user so that they see they probably messed up and that's why they
their nodes
* aren't talking to each other.
*
* This string is of the form "#name-XY".
*
* Where X is a letter from A to Z (base26), and formed by xoring all the bytes of the PSK together.
* Y is not yet used but should eventually indicate 'speed/range' of the link
*
* This function will also need to be implemented in GUI apps that talk to the radio.
*
* https://github.com/meshtastic/Meshtastic-device/issues/269
*/
const char *getChannelName();
@cyclomies thank you for the prodding and help. I'm happy to add more
detail, can you insert a few questions inline? Then I'll answer and
hopefully that will be enough to be useful for others.
The NVS copies of hte BLE pairing info for clients were getting corrupted
occasionally. So I went googling and found some plausible bug reports
but nothing that was an exact match. Then I looked at the arduino-esp32
binaries for the ESP-IDF framework. They were fairly old (Jan 20).
Looking through the commits on ESP-IDF release3.3 it seems like there have
been a few fixes for mutual exclusion errors wrt bluetooth. So I punted
and tried updating ESP-IDF to latest and everything seems fairly solid
now. Currently running a long test run with three nodes.
Meshtastic prompted me to get a couple boards to try, and I had to figure out what frequency. Canada uses the same US902-928 as the US, add it to the list for simplicity.
Not sure where to find an "official" reference, but there's a reference here: https://www.thethingsnetwork.org/docs/lorawan/frequencies-by-country.html
This was a good one. Two problems
1) We've apparently always been using hte sparkfun API the wrong way, but
but we mostly got lucky.
2) Changing to use the API correctly (asyncronously) exposed a bug in
the library - fixed in a seperate commit
The SH1106 is almost indistinguisable from a SSD1306.
- the nr of columns in the sh1106 is 132 vs 128
- use the proper includes/library functions when in use
inexpensive GPS mesh radios as an extensible, super long battery life mesh GPS communicator. These radios are great for hiking, skiing, paragliding -
essentially any hobby where you don't have reliable internet access. Each member of your private mesh can always see the location and distance of all other
members and any text messages sent to your group chat.
@@ -22,24 +22,41 @@ This software is 100% open source and developed by a group of hobbyist experimen
- [T-Beam V1.1 w/ NEO-6M - special Meshtastic version](https://www.aliexpress.com/item/4001178678568.html) (Includes built-in OLED display and they have **preinstalled** the meshtastic software)
- [T-Beam V0.7 w/ NEO-6M](https://www.aliexpress.com/item/4000574335430.html) (will work but **you must use the tbeam0.7 firmware ** - but the T-Beam V1.0 or later are better!)
Note: The GPS and LoRa stock antennas should be placed in a way, that the GPS antenna faces the sky and the LoRa antenna radiates 360 degrees horizontally. For better GPS reception you might want to [upgrade the GPS antenna](https://meshtastic.discourse.group/t/the-importance-of-gps-antennas-and-request-to-3d-case-documentation-people/1505) and to properly align the antennas you might want to upgrade to a LoRa antenna that can be adjusted to radiate into the right directions.
**Make sure to get the frequency for your country**
- US/JP/AU/NZ - 915MHz
- US/JP/AU/NZ/CA - 915MHz
- CN - 470MHz
- EU - 868MHz, 433MHz
- full list of LoRa frequencies per region is available [here](https://www.thethingsnetwork.org/docs/lorawan/frequencies-by-country.html)
Getting a version that includes a screen is optional, but highly recommended.
@@ -47,6 +64,8 @@ Getting a version that includes a screen is optional, but highly recommended.
Prebuilt binaries for the supported radios are available in our [releases](https://github.com/meshtastic/Meshtastic-esp32/releases). Your initial installation has to happen over USB from your Mac, Windows or Linux PC. Once our software is installed, all future software updates happen over bluetooth from your phone.
Be **very careful** to install the correct load for your board. In particular the popular 'T-BEAM' radio from TTGO is not called 'TTGO-Lora' (that is a different board). So don't install the 'TTGO-Lora' build on a TBEAM, it won't work correctly.
Please post comments on our [group chat](https://meshtastic.discourse.group/) if you have problems or successes.
### Installing from a GUI - Windows and Mac
@@ -90,10 +109,10 @@ Hard resetting via RTS pin...
```
5. cd into the directory where the release zip file was expanded.
6. Install the correct firmware for your board with `device-install.sh firmware-_board_-_country_.bin`.
Note: If you have previously installed meshtastic, you don't need to run this full script instead just run `esptool.py --baud 921600 write_flash 0x10000 firmware-_board_-_country_-_version_.bin`. This will be faster, also all of your current preferences will be preserved.
@@ -168,7 +187,7 @@ Hard resetting via RTS pin...
# Meshtastic Android app
The companion (optional) Meshtastic Android app is [here](https://github.com/meshtastic/Meshtastic-Android). You can also download it on Google Play.
The companion (optional) Meshtastic Android app is [here](https://play.google.com/store/apps/details?id=com.geeksville.mesh&referrer=utm_source%3Dgithub-dev-readme). You can also download it on Google Play.
inexpensive (\$30 ish) GPS radios as an extensible, long battery life, secure, mesh GPS communicator. These radios are great for hiking, skiing, paragliding - essentially any hobby where you don't have reliable internet access. Each member of your private mesh can always see the location and distance of all other members and any text messages sent to your group chat.
The radios automatically create a mesh to forward packets as needed, so everyone in the group can receive messages from even the furthest member. The radios will optionally work with your phone, but no phone is required.
Note: Questions after reading this? See our new [forum](https://meshtastic.discourse.group/).
### Uses
## Uses
- Outdoor sports where cellular coverage is limited. (Hiking, Skiing, Boating, Paragliding, Gliders etc..)
- Applications where closed source GPS communicators just won't cut it (it is easy to add features for glider pilots etc...)
@@ -17,7 +17,7 @@ Note: Questions after reading this? See our new [forum](https://meshtastic.disco
[](https://www.youtube.com/watch?v=WlNbMbVZlHI "Meshtastic early demo")
### Features
## Features
Not all of these features are fully implemented yet - see **important** disclaimers below. But they should be in by the time we decide to call this project beta (three months?)
@@ -28,17 +28,28 @@ Not all of these features are fully implemented yet - see **important** disclaim
- Shows direction and distance to all members of your channel
- Directed or broadcast text messages for channel members
- Open and extensible codebase supporting multiple hardware vendors - no lock in to one vendor
- Communication API for bluetooth devices (such as our Android app) to use the mesh. An iOS application is in the works. And [Meshtastic-python](https://pypi.org/project/meshtastic/) provides access from desktop computers.
- Communication API for bluetooth devices (such as our Android app) to use the mesh. An iOS application is in the works. And [Meshtastic-python](https://pypi.org/project/meshtastic/) provides access from desktop computers.
- Very easy sharing of private secured channels. Just share a special link or QR code with friends and they can join your encrypted mesh
This project is currently in beta testing but it is fairly stable and feature complete - if you have questions please [join our discussion forum](https://meshtastic.discourse.group/).
This software is 100% open source and developed by a group of hobbyist experimenters. No warranty is provided, if you'd like to improve it - we'd love your help. Please post in the [forum](https://meshtastic.discourse.group/).
### Beginner's Guide
For an detailed walk-through aimed at beginners, we recommend [meshtastic.letstalkthis.com](https://meshtastic.letstalkthis.com/).
### Related Groups
Telegram group for **Italy**-based users [t.me/meshtastic_italia](http://t.me/meshtastic_italia) (Italian language, unofficial).<br/>
Telegram group for **Russian**-based users [t.me/meshtastic_russia](https://t.me/meshtastic_russia) (Russian language, unofficial).
# Updates
Note: Updates are happening almost daily, only major updates are listed below. For more details see our forum.
- 09/14/2020 - 1.0.0 Now with over 1700 android users, over 2000 nodes and translated into 15 languages. This project will always be a "beta" experiment, but now quite usable. We are currently selecting 1.1 features in our discussion forum.
- 06/24/2020 - 0.7.x Now with over 1000 android users, over 600 people using the radios and translated into 22 languages. Fairly stable and we are working through bugs to get to 1.0.
- 06/04/2020 - 0.6.7 Beta releases of both the application and the device code are released. Features are fairly solid now with a sizable number of users.
- 04/28/2020 - 0.6.0 [Python API](https://pypi.org/project/meshtastic/) released. Makes it easy to use meshtastic devices as "zero config / just works" mesh transport adapters for other projects.
- 04/20/2020 - 0.4.3 Pretty solid now both for the android app and the device code. Many people have donated translations and code. Probably going to call it a beta soon.
@@ -51,7 +62,7 @@ Note: Updates are happening almost daily, only major updates are listed below. F
Our Android application is available here:
[](https://play.google.com/store/apps/details?id=com.geeksville.mesh&referrer=utm_source%3Dhomepage%26anid%3Dadmob)
[](https://play.google.com/store/apps/details?id=com.geeksville.mesh&referrer=utm_source%3Dgithub-homepage)
The link above will return older more stable releases. We would prefer if you join our alpha-test group, because the application is rapidly improving. Three steps to opt-in to the alpha- test:
@@ -61,18 +72,25 @@ The link above will return older more stable releases. We would prefer if you jo
If you'd like to help with development, the source code is [on github](https://github.com/meshtastic/Meshtastic-Android).
The app is also distributed for Amazon Fire devices via the Amazon appstore: [](https://www.amazon.com/Geeksville-Industries-Meshtastic/dp/B08CY9394Q)
## Supported hardware
We currently support two brands of radios. The [TTGO T-Beam](https://www.aliexpress.com/item/4000119152086.html) and the [Heltec LoRa 32](https://heltec.org/project/wifi-lora-32/). Most people should buy the T-Beam and a 18650 battery (total cost less than \$35). Make
sure to buy the frequency range which is legal for your country. For the USA, you should buy the 915MHz version. Getting a version that include a screen is optional, but highly recommended.
We currently support two brands of radios. The [TTGO T-Beam](https://www.aliexpress.com/item/4001178678568.html) and the [Heltec LoRa 32](https://heltec.org/project/wifi-lora-32/). Most people should buy the T-Beam and a 18650 battery (total cost less than \$35). Also, the version of the T-Beam we link to is shipped with Meshtastic **preinstalled** by TTGO, so you don't have to install it yourself.
Make sure to buy the frequency range which is legal for your country. For the USA, you should buy the 915MHz version. Getting a version that include a screen is optional, but highly recommended.
Instructions for installing prebuilt firmware can be found [here](https://github.com/meshtastic/Meshtastic-esp32/blob/master/README.md).
For a nice printable cases:
For a nice looking cases:
1. TTGO T-Beam V0 see this [design](https://www.thingiverse.com/thing:3773717) by [bsiege](https://www.thingiverse.com/bsiege).
2. TTGO T_Beam V1 see this [design](https://www.thingiverse.com/thing:3830711) by [rwanrooy](https://www.thingiverse.com/rwanrooy) or this [remix](https://www.thingiverse.com/thing:3949330) by [8ung](https://www.thingiverse.com/8ung)
3. Heltec Lora32 see this [design](https://www.thingiverse.com/thing:3125854) by [ornotermes](https://www.thingiverse.com/ornotermes).
- 3D printable cases
1. TTGO T-Beam V0 see this [design](https://www.thingiverse.com/thing:3773717) by [bsiege](https://www.thingiverse.com/bsiege).
2. TTGO T_Beam V1 (SMA) see this [design](https://www.thingiverse.com/thing:3830711) by [rwanrooy](https://www.thingiverse.com/rwanrooy) or this [remix](https://www.thingiverse.com/thing:3949330) by [8ung](https://www.thingiverse.com/8ung)
3. TTGO T_Beam V1 (IPEX) see this [design](https://www.thingiverse.com/thing:4587297) by [drewsed](https://www.thingiverse.com/drewsed)
4. Heltec Lora32 see this [design](https://www.thingiverse.com/thing:3125854) by [ornotermes](https://www.thingiverse.com/ornotermes).
- Laser-cut cases
1. TTGO T_Beam V1 (SMA) see this [design](https://www.thingiverse.com/thing:4552771) by [jefish](https://www.thingiverse.com/jefish)
@@ -4,7 +4,7 @@ This project is still pretty young but moving at a pretty good pace. Not all fea
Most of these problems should be solved by the beta release (within three months):
- We don't make these devices and they haven't been tested by UL or the FCC. If you use them you are experimenting and we can't promise they won't burn your house down ;-)
- The encryption [implementation](software/crypto.md) has not been reviewed by an expert. (Are you an expert? Please help us)
- The encryption implementation is good but see this list of [caveats](software/crypto.md#summary-of-strengthsweaknesses-of-our-current-implementation) to determine risks you might face.
- A number of (straightforward) software work items have to be completed before battery life matches our measurements, currently battery life is about three days. Join us on chat if you want the spreadsheet of power measurements/calculations.
- The Android API needs to be documented better
- No one has written an iOS app yet. But some good souls [are talking about it](https://github.com/meshtastic/Meshtastic-esp32/issues/14) ;-)
We use the same channel maps as LoRaWAN (though this is not LoRaWAN).


See [this site](https://www.rfwireless-world.com/Tutorials/LoRa-channels-list.html) for more information.
## LoRaWAN Europe Frequency Band
The maximum power allowed is +14dBM.
The maximum power allowed is +14dBm ERP (Effective Radiated Power, see [this site](https://en.wikipedia.org/wiki/Effective_radiated_power) for more information).
### 433 MHz
@@ -24,7 +24,82 @@ Channel zero starts at 865.20 MHz
LoRaWAN defines 64, 125 kHz channels from 902.3 to 914.9 MHz increments.
The maximum output power for North America is +30 dBM.
The maximum output power for North America is +30 dBm ERP.
The band is from 902 to 928 MHz. It mentions channel number and its respective channel frequency. All the 13 channels are separated by 2.16 MHz with respect to the adjacent channels.
Channel zero starts at 903.08 MHz center frequency.
Channel zero starts at 903.08 MHz center frequency.
## Data-rates
### About
Various data-rates are selectable when configuring a channel and are inversely proportional to the theoretical range of the devices.
Considerations:
* Spreading Factor - How much we "spread" our data over time.
* * Each step up in Spreading Factor dobules the airtime to transmit.
* * Each step up in Spreading Factor adds about 2.5db extra link budget.
* Bandwidth - How big of a slice of the spectrum we use.
* * Each doubling of the bandwidth is almost 3db less link budget.
* * Bandwidths less than 31 may be unstable unless you have a high quality Crystal Ossilator.
* Coding Rate - How much redundency we encode to resist noise.
* * Increasing coding rate increases reliability while decrasing data-rate.
* * 4/5 - 1.25x overhead
* * 4/6 - 1.5x overhead
* * 4/7 - 1.75x overhead
* * 4/8 - 2x overhead
### Pre-Defined
We have four predefined channels. These are the most common settings and have been proven to work well:
| Channel setting | Alt Channel Name | Data-rate | SF / Symbols | Coding Rate | Bandwidth | Link Budget |
| Short range (but fast) | Short Fast | 21.875 kbps | 7 / 128 | 4/5 | 125 | 134dB |
| Medium range (but fast) | Medium | 5.469 kbps | 7 / 128 | 4/5 | 500 | 140dB |
| Long range (but slower) | Long Alt | 0.275 kbps | 9 / 512 | 4/8 | 31 | 153dB |
| Very long range (but slow) | Long Slow | 0.183 kbps (default) | 12 / 4096 | 4/8 | 125 | 154dB |
The link budget used by these calculations assumes a transmit power of 17dBm and an antenna with 0dB gain. Adjust your link budget assumptions based on your actual devices.
### Custom Settings
You may want to select other channels for your usage. The other settings can be set by using the Python API.
After applying the settings, you will need to restart the device. After your device is restarted, it will generate a new crypto key and you will need to share the newly generated QR Code or URL to all your other devices.
Some example settings:
| Data-rate | SF / Symbols | Coding Rate | Bandwidth | Link Budget | Note |
| 0.073 kbps | 12 / 4096 | 4/5 | 31 | 160dB | Twice the range and/or coverage of "Long Slow", low resliance to noise |
| 0.046 kbps | 12 / 4096 | 4/8 | 31 | 160dB | Twice the range and/or coverage of "Long Slow", high resliance to noise |
The link budget used by these calculations assumes a transmit power of 17dBm and an antenna with 0dB gain. Adjust your link budget assumptions based on your actual devices.
These channel settings may have not been tested. Use at your own discression. Share on https://meshtastic.discourse.group with your successes or failure.
## Cryptography
The preshared key used by the devices can be modified.
* 0 = No crypto
* 1 = Default channel key
* 2 - 10 = The default channel key, except with 1 through 9 added to the last byte
Use of cryptography can also be modified. To disable cryptography (maybe useful if you have HAM radio license):
- device wakes, turns BLE on and phone doesn't notice (while phone was sitting in auto-connect)
- E22 bringup
-encryption review findings writeup
-turn on modem-sleep mode - https://github.com/espressif/arduino-esp32/issues/1142#issuecomment-512428852
You probably don't care about this section - skip to the next one.
## before next release
*DONE test latest firmware update with is_router
*DONE firmware OTA updates of is_router true nodes fails?
* DONE add UI in android app to reset to defaults https://github.com/meshtastic/Meshtastic-Android/issues/263
* DONE TEST THIS! changing channels requires a reboot to take effect https://github.com/meshtastic/Meshtastic-device/issues/752
* DIBE bug report with remote info request timing out
* DONE retest channel changing in android (using sim?)
* DONE move remote admin doc from forum into git
* DONE check crashlytics
* DONE ask for a documentation czar
* DONE timestamps on oled screen are wrong - don't seem to be updating based on message rx (actually: this is expected behavior when no node on the mesh has GPS time)
* DONE add ch-del
* DONE channel hash suffixes are wrong on android
* DONE before next relase: test empty channel sets on android
* DONE channel sharing in android
* DONE test 1.0 firmware update on android
* DONE test 1.1 firmware update on android
* DONE test 1.2.10 firmware update on android
* DONE test link sharing on android
* FIXED? luxon bug report - seeing rx acks for nodes that are not on the network
* DONE release py
* DONE show GPS time only if we know what global time is
* DONE android should always provide time to nodes - so that it is easier for the mesh to learn the current time
## MQTT
## Multichannel support
* DONE cleanup the external notification and serial plugins
* non ack version of stress test fails sometimes!
* tx fault test has a bug #734 - * turn off fault 8: https://github.com/meshtastic/Meshtastic-device/issues/734
* DONE move device types into an enum in nodeinfo
* DONE fix android to use new device types for firmware update
* nrf52 should preserve local time across reset
* cdcacm bug on nrf52: emittx thinks it emitted but client sees nothing. works again later
* nrf52: segger logs have errors in formatting that should be impossible (because not going through serial, try stalling on segger)
* DONE call RouterPlugin for *all* packets - not just Router packets
* DONE generate channel hash from the name of the channel+the psk (not just one or the other)
* DONE send a hint that can be used to select which channel to try and hash against with each message
* DONE remove deprecated
* DONE fix setchannel in phoneapi.cpp
* DONE set mynodeinfo.max_channels
* DONE set mynodeinfo.num_bands (formerly num_channels)
* DONE fix sniffing of non Routing packets
* DONE enable remote setttings access by moving settings operations into a regular plugin (move settings ops out of PhoneAPI)
* DONE move portnum up?
* DONE remove region specific builds from the firmware
* DONE test single channel without python
* DONE Use "default" for name if name is empty
* DONE fix python data packet receiving (nothing showing in log?)
* DONE use get channels & get settings from android
* DONE use set-channel from python
* DONE make settings changes from python work
* DONE pthon should stop fetching channels once we've reached our first empty channel definition (hasSettings == true)
* DONE add check for old devices with new API library
* DONE release python api
* DONE release protobufs
* DONE release to developers
* DONE fix setch-fast in python tool
* age out pendingrequests in the python API
* DONE stress test channel download from python, sometimes it seems like we don't get all replies, bug was due to simultaneous android connection
* DONE combine acks and responses in a single message if possible (do routing plugin LAST and drop ACK if someone else has already replied)
* DONE don't send packets we received from the phone BACK TOWARDS THE PHONE (possibly use fromnode 0 for packets the phone sends?)
* DONE fix 1.1.50 android debug panel display
* DONE test android channel setting
* DONE release to users
* DONE warn in android app about unset regions
* DONE use set-channel from android
* DONE add gui in android app for setting region
* DONE clean up python channel usage
* DONE use bindToChannel to limit admin access for remote nodes
* DONE move channels and radio config out of device settings
* DONE test remote info and remote settings changes
* make python tests more exhaustive
* DONE pick default random admin key
* exclude admin channels from URL?
* make a way to share just secondary channels via URL
* generalize the concept of "shortstrings" use it for both PSKs and well known channel names. Possibly use a ShortString class.
* use single byte 'well known' channel names for admin, gpio, etc...
* use presence of gpio channel to enable gpio ops, same for serial etc...
* DONE restrict gpio & serial & settings operations to the admin channel (unless local to the current node)
* DONE add channel restrictions for plugins (and restrict routing plugin to the "control" channel)
* stress test multi channel
* DONE investigate @mc-hamster report of heap corruption
* DONE use set-user from android
* untrusted users should not be allowed to provide bogus times (via position broadcasts) to the rest of the mesh. Invent a new lowest quality notion of UntrustedTime.
* use portuino TCP connection to debug with python API
* document the relationship between want_response (indicating remote node received it) and want_ack (indicating that this message should be sent reliably - and also get acks from the first rx node and naks if it is never delivered)
* DONE android should stop fetching channels once we've reached our first empty channel definition (hasSettings == true)
* DONE warn in python api if we are too new to talk to the device code
* DONE make a post warning about 1.2, telling how to stay on old android & python clients. link to this from the android dialog message and python version warning.
* DONE "FIXME - move the radioconfig/user/channel READ operations into SettingsMessage as well"
* DONE scrub protobufs to make sure they are absoloute minimum wiresize (in particular Data, ChannelSets and positions)
* DONE change syncword (now ox2b)
* allow chaning packets in single transmission - to increase airtime efficiency and amortize packet overhead
* DONE move most parts of meshpacket into the Data packet, so that we can chain multiple Data for sending when they all have a common destination and key.
* when selecting a MeshPacket for transmit, scan the TX queue for any Data packets we can merge together as a WirePayload. In the low level send/rx code expand that into multiple MeshPackets as needed (thus 'hiding' from MeshPacket that over the wire we send multiple datapackets
* DONE confirm we are still calling the plugins for messages inbound from the phone (or generated locally)
* DONE confirm we are still multi hop routing flood broadcasts
* DONE confirm we are still doing resends on unicast reliable packets
* add history to routed packets: https://meshtastic.discourse.group/t/packet-source-tracking/2764/2
* add support for full DSR unicast delivery
* DONE move acks into routing
* DONE make all subpackets different versions of data
* DONE move routing control into a data packet
* have phoneapi done via plugin (will allow multiple simultaneous API clients - stop disabling BLE while using phone API)
* use reference counting and dynamic sizing for meshpackets.
* let multiple PhoneAPI endpoints work at once
* allow multiple simultaneous bluetooth connections (create the bluetooth phoneapi instance dynamically based on client id)
* DONE figure out how to add micro_delta to position, make it so that phone apps don't need to understand it?
* only send battery updates a max of once a minute
* DONE add python channel selection for sending
* DONE record recevied channel in meshpacket
* test remote settings operations (confirm it works 3 hops away)
* DONE make a primaryChannel global and properly maintain it when the phone sends setChannel
* DONE move setCrypto call into packet send and packet decode code
* implement 'small location diffs' change
* move battery level out of position?
* consider "A special exception (FIXME, not sure if this is a good idea) - packets that arrive on the local interface
are allowed on any channel (this lets the local user do anything)." Probably by adding a "secure_local_interface" settings bool.
* DOUBLE CHECK android app can still upgrade 1.1 and 1.0 loads
For app cleanup:
* use structured logging to kep logs in ram. Also send logs as packets to api clients
* DONE writeup nice python options docs (common cases, link to protobuf docs)
* have android app link to user manual
* DONE only do wantReplies once per packet type, if we change network settings force it again
* update positions and nodeinfos based on packets we just merely witness on the mesh. via isPromsciousPort bool, remove sniffing
* DONE make device build always have a valid version
* DONE do fixed position bug https://github.com/meshtastic/Meshtastic-device/issues/536
* DONE have python tool check max packet size before sending to device
* DONE if request was sent reliably, send reply reliably
* DONE require a recent python api to talk to these new device loads
* DONE require a recent android app to talk to these new device loads
* DONE fix handleIncomingPosition
* DONE move want_replies handling into plugins
* DONE on android for received positions handle either old or new positions / user messages
* DONE on android side send old or new positions as needed / user messages
* DONE test python side handle new position/user messages
* DONE make a gpio example. --gpiowrb 4 1, --gpiord 0x444, --gpiowatch 0x3ff
* DONE fix position sending to use new plugin
* DONE Add SinglePortNumPlugin - as the new most useful baseclass
* DONE move positions into regular data packets (use new app framework)
* DONE move user info into regular data packets (use new app framework)
* DONE test that positions, text messages and user info still work
* DONE test that position, text messages and user info work properly with new android app and old device code
* DONE do UDP tunnel
* DONE fix the RTC drift bug
* move python ping functionality into device, reply with rxsnr info
* use channels for gpio security https://github.com/meshtastic/Meshtastic-device/issues/104
* MeshPackets for sending should be reference counted so that API clients would have the option of checking sent status (would allow removing the nasty 30 sec timer in gpio watch sending)
For high speed/lots of devices/short range tasks:
- When guessing numhops for sending: if I've heard from many local (0 hop neighbors) decrease hopcount by 2 rather than 1.
This should nicely help 'router' nodes do the right thing when long range, or if there are many local nodes for short range.
- fix timeouts/delays to be based on packet length at current radio settings
* update faq with antennas https://meshtastic.discourse.group/t/range-test-ideas-requested/738/2
* update faq on recommended android version and phones
* add help link inside the app, reference a page on the wiki
* turn on amazon reviews support
* add a tablet layout (with map next to messages) in the android app
# Completed
## eink 1.0
* DONE check email of reported issues
* DONE turn off vbus driving (in bootloader)
* new battery level sensing
* current draw no good
* DONE: fix backlight
* DONE - USB is busted because of power enable mode?
* test CPU voltage? something is bad with RAM (removing eink module does not help)
* support new flash chip in appload, possibly use low power mode
* swbug! stuck busy tx occurred!
# Old docs to merge
MESH RADIO PROTOCOL
Old TODO notes on the mesh radio protocol, merge into real docs someday...
for each named group we have a pre-shared key known by all group members and
wrapped around the device. you can only be in one group at a time (FIXME?!) To
join the group we read a qr code with the preshared key and ParamsCodeEnum. that
gets sent via bluetooth to the device. ParamsCodeEnum maps to a set of various
radio params (regulatory region, center freq, SF, bandwidth, bitrate, power
etc...) so all members of the mesh can have their radios set the same way.
once in that group, we can talk between 254 node numbers.
to get our node number (and announce our presence in the channel) we pick a
random node number and broadcast as that node with WANT-NODENUM(my globally
unique name). If anyone on the channel has seen someone _else_ using that name
within the last 24 hrs(?) they reply with DENY-NODENUM. Note: we might receive
multiple denies. Note: this allows others to speak up for some other node that
might be saving battery right now. Any time we hear from another node (for any
message type), we add that node number to the unpickable list. To dramatically
decrease the odds a node number we request is already used by someone. If no one
denies within TBD seconds, we assume that we have that node number. As long as
we keep talking to folks at least once every 24 hrs, others should remember we
have it.
Once we have a node number we can broadcast POSITION-UPDATE(my globally unique
name, lat, lon, alt, amt battery remaining). All receivers will use this to a)
update the mapping of who is at what node nums, b) the time of last rx, c)
position. If we haven't heard from that node in a while we reply to that node
(only) with our current POSITION_UPDATE state - so that node (presumably just
rejoined the network) can build a map of all participants.
We will periodically broadcast POSITION-UPDATE as needed based on distance moved
or a periodic minimum heartbeat.
If user wants to send a text they can SEND_TEXT(dest user, short text message).
Dest user is a node number, or 0xff for broadcast.
# Medium priority
Items to complete before the first beta release.
Items to complete before 1.0.
- turn on watchdog timer (because lib code seems buggy)
- show battery level as % full
- rx signal measurements -3 marginal, -9 bad, 10 great, -10 means almost unusable. So scale this into % signal strength. preferably as a graph, with an X indicating loss of comms.
# Pre-beta priority
During the beta timeframe the following improvements 'would be nice'
# Post 1.0 ideas
- finish DSR for unicast
- check fcc rules on duty cycle. we might not need to freq hop. https://www.sunfiretesting.com/LoRa-FCC-Certification-Guide/ . Might need to add enforcement for europe though.
- pick channel center frequency based on channel name? "dolphin" would hash to 900Mhz, "cat" to 905MHz etc? allows us to hide the concept of channel # from hte user.
- make a no bluetooth configured yet screen - include this screen in the loop if the user hasn't yet paired
- if radio params change fundamentally, discard the nodedb
- re-enable the bluetooth battery level service on the T-BEAM
- implement first cut of router mode: preferentially handle flooding, and change sleep and GPS behaviors
- provide generalized (but slow) internet message forwarding service if one of our nodes has internet connectivity (MQTT) [ Not a requirement but a personal interest ]
# Low priority
# Low priority ideas
Items after the first final candidate release.
- implement nimble battery level service
- Nimble implement device info service remaining fields (hw version etc)
- Turn on RPA addresses for the device side in Nimble
- Try to teardown less of the Nimble protocol stack across sleep
- dynamic frequency scaling could save a lot of power on ESP32, but it seems to corrupt uart (even with ref_tick set correctly)
- Change back to using a fixed sized MemoryPool rather than MemoryDynamic (see bug #149)
- scan to find channels with low background noise? (Use CAD mode of the RF95 to automatically find low noise channels)
- If the phone doesn't read fromradio mailbox within X seconds, assume the phone is gone and we can stop queing location msgs
@@ -57,9 +302,16 @@ Items after the first final candidate release.
- split out the software update utility so other projects can use it. Have the appload specify the URL for downloads.
- read the PMU battery fault indicators and blink/led/warn user on screen
- discard very old nodedb records (> 1wk)
- add a watchdog timer
- handle millis() rollover in GPS.getTime - otherwise we will break after 50 days
- report esp32 device code bugs back to the mothership via android
- change BLE bonding to something more secure. see comment by pSecurity->setAuthenticationMode(ESP_LE_AUTH_BOND)
If you've landed here that means your android application is too old for the running device firmware. Usually our updates are backwards compatible, but about once a year we have a "major protocol update" which requires all apps and devices to update to keep working with that version. Version 1.2 in March 2021 was one of those updates.
If you have problems/questions please post in our [forum](https://meshtastic.discourse.group) and some nice person will probably help.
This project uses the simple PlatformIO build system. You can use the IDE, but for brevity
in these instructions I describe use of their command line tool.
This project uses the simple PlatformIO build system. PlatformIO is an extension to Microsoft VSCode. Workflows from building from the GUI or from the commandline are listed below.
1. Purchase a suitable radio (see above)
If you encounter any problems, please post a question in [our forum](meshtastic.discourse.group). And when you learn a fix, update these instructions for the next person (i.e. edit this file and send in a [pull-request](https://opensource.com/article/19/7/create-pull-request-github) which we will eagerly merge).
## GUI
1. Purchase a suitable [radio](https://github.com/meshtastic/Meshtastic-device/wiki/Hardware-Information).
6. Click the PlatformIO icon on the side bar. 
7. Under `Quick Access, Miscellaneous, Clone Git Project` enter the URL of the Meshtastic repo found [here](https://github.com/meshtastic/Meshtastic-device). 
8. Select a file location to save the repo.
9. Once loaded, open the `platformio.ini` file.
10. At the line `default_envs` you can change it to the board type you are building for ie. `tlora-v2, tlora-v1, tlora-v2-1-1.6, tbeam, heltec, tbeam0.7` (boards are listed further down in the file).
11. The hardware can be configured for different countries by adding a definition to the `configuration.h` file. `#define HW_VERSION_US` or `HW_VERSION_EU433, HW_VERSION_EU865, HW_VERSION_CN, HW_VERSION_JP`. Other country settings can be found in `MeshRadio.h`. The default is `HW_VERSION_US`.
12. Click the PlatformIO icon on the side bar. Under `Project Tasks` you can now build or upload.
Note - To get a clean build you may have to delete the auto-generated file `./.vscode/c_cpp_properties.json`, close and re-open Visual Studio and WAIT until the file is auto-generated before compiling again.
## Command Line
1. Purchase a suitable [radio](https://github.com/meshtastic/Meshtastic-device/wiki/Hardware-Information).
4. Run `git submodule update --init --recursive` to pull in dependencies this project needs.
5. If you are outside the USA, edit [platformio.ini](/platformio.ini) to set the correct frequency range for your country. The line you need to change starts with `hw_version` and instructions are provided above that line. Options are provided for `EU433`, `EU835`, `CN`, `JP` and `US` (default). Pull-requests eagerly accepted for other countries.
5. If you are outside the USA, run "export COUNTRY=EU865" (or whatever) to set the correct frequency range for your country. Options are provided for `EU433`, `EU865`, `CN`, `JP` and `US` (default). Pull-requests eagerly accepted for other countries.
6. Plug the radio into your USB port
7. Type `pio run --environment XXX -t upload` (This command will fetch dependencies, build the project and install it on the board via USB). For XXX, use the board type you have (either `tbeam`, `heltec`, `ttgo-lora32-v1`, `ttgo-lora32-v2`).
7. Type `pio run --environment XXX -t upload` (This command will fetch dependencies, build the project and install it on the board via USB). For XXX, use the board type you have (either `tlora-v2, tlora-v1, tlora-v2-1-1.6, tbeam, heltec, tbeam0.7`).
8. Platform IO also installs a very nice VisualStudio Code based IDE, see their [tutorial](https://docs.platformio.org/en/latest/tutorials/espressif32/arduino_debugging_unit_testing.html) if you'd like to use it.
## Decoding stack traces
### Option 1
If you get a crash, you can decode the addresses from the `Backtrace:` line:
1. Save the `Backtrace: 0x....` line to a file, e.g., `backtrace.txt`.
2. Run `bin/exception_decoder.py backtrace.txt` (this uses symbols from the
last `firmware.elf`, so you must be running the same binary that's still in
your `.pio/build` directory).
### Option 2
You can run the exception decoder to monitor the serial output and decode backtraces in real time.
Version 1.2 of the software adds support for "multiple (simultaneous) channels". The idea behind this feature is that a mesh can allow multiple users/groups to be share common mesh infrastructure. Even including routing messages for others when no one except that subgroup of users has the encryption keys for their private channel.
### What is the PRIMARY channel
The way this works is that each node keeps a list of channels it knows about. One of those channels (normally the first 1) is labelled as the "PRIMARY" channel. The primary channel is the **only** channel that is used to set radio parameters. i.e. this channel controls things like spread factor, coding rate, bandwidth etc... Indirectly this channel also is used to select the specific frequency that all members of this mesh are talking over.
This channel may or may not have a PSK (encryption). If you are providing mesh to 'the public' we recommend that you always leave this channel with its default psk. The default PSK is technically encrypted (and random users sniffing the ether would have to use meshtastic to decode it), but the key is included in the github source code and you should assume any 'attacker' would have it. But for a 'public' mesh you want this, because it allows anyone using meshtastic in your area to send packets through 'your' mesh.
Note: Older meshtastic applications that don't yet understand multi-channel support will only show the user this channel.
### How to use SECONDARY channels
Any channel you add after that PRIMARY channel is SECONDARY. Secondary channels are used only for encyryption and (in the case of some special applications) security. If you would like to have a private channel over a more public mesh, you probably want to create a SECONDARY channel. When sharing that URL with your private group you will share the "Complete URL". The complete URL includes your secondary channel (for encryption) and the primary channel (to provide radio/mesh access).
Secondary channels **must** have a PSK (encryption).
@@ -5,33 +5,47 @@ the project developers are not cryptography experts. Therefore we ask two things
- If you are a cryptography expert, please review these notes and our questions below. Can you help us by reviewing our
notes below and offering advice? We will happily give as much or as little credit as you wish ;-).
- Consider our existing solution 'alpha' and probably fairly secure against a not particularly aggressive adversary. But until
it is reviewed by someone smarter than us, assume it might have flaws.
- Consider our existing solution 'alpha' and probably fairly secure against a not particularly aggressive adversary
(but we can't yet make a more confident statement).
## Notes on implementation
## Summary of strengths/weaknesses of our current implementation
Based on comments from reviewers (see below), here's some tips for usage of these radios. So you can know the level of protection offered:
* It is pretty likely that the AES256 security is implemented 'correctly' and an observer will not be able to decode your messages.
* Warning: If an attacker is able to get one of the radios in their posession, they could either a) extract the channel key from that device or b) use that radio to listen to new communications.
* Warning: If an attacker is able to get the "Channel QR code/URL" that you share with others - that attacker could then be able to read any messages sent on the channel (either tomorrow or in the past - if they kept a raw copy of those broadcast packets)
Possible future areas of work (if there is enough interest - post in our [forum](https://meshtastic.discourse.group) if you want this):
1. Optionally requiring users to provide a PIN to regain access to the mesh. This could be based on: intentionally locking the device, time since last use, or any member could force all members to reauthenticate,
2. Until a device reauthenticates, any other access via BLE or USB would be blocked (this would protect against attackers who are not prepared to write custom software to extract and reverse engineer meshtastic flash memory)
3. Turning on read-back protection in the device fuse-bits (this would extend protection in #2 to block all but **extremely** advanced attacks involving chip disassembly)
4. Time limiting keys used for message transmission and automatically cycling them on a schedule. This would protect past messages from being decoded even if an attacker learns the current key.
### Notes for reviewers
If you are reviewing our implementation, this is a brief statement of our method.
- We do all crypto at the SubPacket (payload) level only, so that all meshtastic nodes will route for others - even those channels which are encrypted with a different key.
- Mostly based on reading [Wikipedia](<https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Counter_(CTR)>) and using the modes the ESP32 provides support for in hardware.
- We use AES256-CTR as a stream cypher (with zero padding on the last BLOCK) because it is well supported with hardware acceleration.
Parameters for our CTR implementation:
- Our AES key is 128 or 256 bits, shared as part of the 'Channel' specification.
-Each SubPacket will be sent as a series of 16 byte BLOCKS.
- The node number concatenated with the packet number is used as the NONCE. This counter will be stored in flash in the device and should essentially never repeat. If the user makes a new 'Channel' (i.e. picking a new random 256 bit key), the packet number will start at zero. The packet number is sent
in cleartext with each packet. The node number can be derived from the "from" field of each packet.
-Each BLOCK for a packet has an incrementing COUNTER. COUNTER starts at zero for the first block of each packet.
- The IV for each block is constructed by concatenating the NONCE as the upper 96 bits of the IV and the COUNTER as the bottom 32 bits. Note: since our packets are small counter will really never be higher than 32 (five bits).
-The node number concatenated with the packet number is used as the NONCE. This nonce will be stored in flash in the device and should essentially never repeat. If the user makes a new 'Channel' (i.e. picking a new random 256 bit key), the packet number will start at zero.
- The packet number is sent in cleartext with each packet. The node number can be derived from the "from" field of each packet. (Cleartext is acceptable because it merely provides IV for each encryption run)
- Each 16 byte BLOCK for a packet has an incrementing COUNTER. COUNTER starts at zero for the first block of each packet.
-The IV for each block is constructed by concatenating the NONCE as the upper 96 bits of the IV and the COUNTER as the bottom 32 bits. Since our packets are small counter portion will really never be higher than 32 (five bits).
```
You can encrypt separate messages by dividing the nonce_counter buffer in two areas: the first one used for a per-message nonce, handled by yourself, and the second one updated by this function internally.
For example, you might reserve the first 12 bytes for the per-message nonce, and the last 4 bytes for internal use. In that case, before calling this function on a new message you need to set the first 12 bytes of nonce_counter to your chosen nonce value, the last 4 to 0, and nc_off to 0 (which will cause stream_block to be ignored). That way, you can encrypt at most 2**96 messages of up to 2**32 blocks each with the same key.
## Comments from reviewer #1
The per-message nonce (or information sufficient to reconstruct it) needs to be communicated with the ciphertext and must be unique. The recommended way to ensure uniqueness is to use a message counter. An alternative is to generate random nonces, but this limits the number of messages that can be securely encrypted: for example, with 96-bit random nonces, you should not encrypt more than 2**32 messages with the same key.
This reviewer is a cryptography professional, but would like to remain anonymous. We thank them for their comments ;-):
Note that for both stategies, sizes are measured in blocks and that an AES block is 16 bytes.
```
I'm assuming that meshtastic is being used to hike in places where someone capable is trying to break it - like you were going to walk around DefCon using these. I spent about an hour reviewing the encryption, and have the following notes:
## Remaining todo
* The write-up isn't quite as clear as the code.
* The code is using AES-CTR mode correctly to ensure confidentiality.
* The comment for initNonce really covers the necessary information.
* I think the bigger encryption question is "what does the encryption need to do"? As it stands, an attacker who has yet to capture any of the devices cannot reasonably capture text or location data. An attacker who captures any device in the channel/mesh can read everything going to that device, everything stored on that device, and any other communication within the channel that they captured in encrypted form. If that capability basically matches your expectations, it is suitable for whatever adventures this was intended for, then, based on information publicly available or widely disclosed, the encryption is good. If those properties are distressing (like, device history is deliberately limited and you don't want a device captured today to endanger the information sent over the channel yesterday) we could talk about ways to achieve that (most likely synchronizing time and replacing the key with its own SHA256 every X hours, and ensuring the old key is not retained unnecessarily).
* Two other things to keep in mind are that AES-CTR does not itself provide authenticity (e.g. an attacker can flip bits in replaying data and scramble the resulting plaintext), and that the current scheme gives some hints about transmission in the size. So, if you worry about an adversary deliberately messing-up messages or knowing the length of a text message, it looks like those might be possible.
- Have the app change the crypto key when the user generates a new channel
I'm guessing that the network behaves somewhat like a store-and-forward network - or, at least, that the goal is to avoid establishing a two-way connection to transmit data. I'm afraid I haven't worked with mesh networks much, but remember studying them briefly in school about ten years ago.
The Bluetooth API is design to have only a few characteristics and most polymorphism comes from the flexible set of Google Protocol Buffers which are sent over the wire. We use protocol buffers extensively both for the bluetooth API and for packets inside the mesh or when providing packets to other applications on the phone.
(This document describes the protocol for external API clients using our devices. If you are interested in running your own code on the device itself, see the [on-device](plugin-api.md) documentation instead)
## A note on MTU sizes
The Device API is design to have only a simple stream of ToRadio and FromRadio packets and all polymorphism comes from the flexible set of Google Protocol Buffers which are sent over the wire. We use protocol buffers extensively both for the bluetooth API and for packets inside the mesh or when providing packets to other applications on the phone.
This device will work with any MTU size, but it is highly recommended that you call your phone's "setMTU function to increase MTU to 512 bytes" as soon as you connect to a service. This will dramatically improve performance when reading/writing packets.
## Streaming version
## MeshBluetoothService
This protocol is **almost** identical when it is deployed over BLE, Serial/USB or TCP (our three currently supported transports for connecting to phone/PC). Most of this document is in terms of the original BLE version, but this section describes the small changes when this API is exposed over a Streaming (non datagram) transport. The streaming version has the following changes:
- We assume the stream is reliable (though the protocol will resynchronize if bytes are lost or corrupted). i.e. we do not include CRCs or error correction codes.
- Packets always have a four byte header (described below) prefixed before each packet. This header provides framing characters and length.
- The stream going towards the radio is only a series of ToRadio packets (with the extra 4 byte headers)
- The stream going towards the PC is a stream of FromRadio packets (with the 4 byte headers), or if the receiver state machine does not see valid header bytes it can (optionally) print those bytes as the debug console from the radio. This allows the device to emit regular serial debugging messages (which can be understood by a terminal program) but also switch to a more structured set of protobufs once it sees that the PC client has sent a protobuf towards it.
The 4 byte header is constructed to both provide framing and to not look line 'normal' 7 bit ASCII.
- Byte 0: START1 (0x94)
- Byte 1: START2 (0xc3)
- Byte 2: MSB of protobuf length
- Byte 3: LSB of protobuf length
The receiver will validate length and if >512 it will assume the packet is corrupted and return to looking for START1. While looking for START1 any other characters are printed as "debug output". For small example implementation of this reader see the meshtastic-python implementation.
## MeshBluetoothService (the BLE API)
This is the main bluetooth service for the device and provides the API your app should use to get information about the mesh, send packets or provision the radio.
@@ -28,7 +44,6 @@ Expected sequence for initial download:
- Read a RadioConfig from "radio" - used to get the channel and radio settings
- Read a User from "user" - to get the username for this node
- Read a MyNodeInfo from "mynode" to get information about this local device
- Write an empty record to "nodeinfo" to restart the nodeinfo reading state machine
- Read a series of NodeInfo packets to build the phone's copy of the current NodeDB for the mesh
- Read a endConfig packet that indicates that the entire state you need has been sent.
- Read a series of MeshPackets until it returns empty to get any messages that arrived for this node while the phone was away
@@ -71,16 +86,20 @@ Not all messages are kept in the fromradio queue (filtered based on SubPacket):
- No WantNodeNum / DenyNodeNum messages are kept
A variable keepAllPackets, if set to true will suppress this behavior and instead keep everything for forwarding to the phone (for debugging)
## Protobuf API
### A note on MTU sizes
This device will work with any MTU size, but it is highly recommended that you call your phone's "setMTU function to increase MTU to 512 bytes" as soon as you connect to a service. This will dramatically improve performance when reading/writing packets.
### Protobuf API
On connect, you should send a want_config_id protobuf to the device. This will cause the device to send its node DB and radio config via the fromradio endpoint. After sending the full DB, the radio will send a want_config_id to indicate it is done sending the configuration.
## Other bluetooth services
### Other bluetooth services
This document focuses on the core mesh service, but it is worth noting that the following other Bluetooth services are also
This document focuses on the core device protocol, but it is worth noting that the following other Bluetooth services are also
provided by the device.
### BluetoothSoftwareUpdate
#### BluetoothSoftwareUpdate
The software update service. For a sample function that performs a software update using this API see [startUpdate](https://github.com/meshtastic/Meshtastic-Android/blob/master/app/src/main/java/com/geeksville/mesh/service/SoftwareUpdateService.kt).
@@ -94,14 +113,15 @@ Characteristics
| e272ebac-d463-4b98-bc84-5cc1a39ee517 | write | data, variable sized, recommended 512 bytes, write one for each block of file |
| 4826129c-c22a-43a3-b066-ce8f0d5bacc6 | write | crc32, write last - writing this will complete the OTA operation, now you can read result |
| 5e134862-7411-4424-ac4a-210937432c77 | read,notify | result code, readable but will notify when the OTA operation completes |
| 5e134862-7411-4424-ac4a-210937432c67 | write | sets the region for programming, currently only 0 (app) or 100 (spiffs) are defined, if not set app is assumed |
| GATT_UUID_SW_VERSION_STR/0x2a28 | read | We also implement these standard GATT entries because SW update probably needs them: |
| GATT_UUID_MANU_NAME/0x2a29 | read | |
| GATT_UUID_HW_VERSION_STR/0x2a27 | read | |
### DeviceInformationService
#### DeviceInformationService
Implements the standard BLE contract for this service (has software version, hardware model, serial number, etc...)
### BatteryLevelService
#### BatteryLevelService
Implements the standard BLE contract service, provides battery level in a way that most client devices should automatically understand (i.e. it should show in the bluetooth devices screen automatically)
The routing protocol for Meshtastic is really quite simple (and suboptimal). It is heavily influenced by the mesh routing algorithm used in [Radiohead](https://www.airspayce.com/mikem/arduino/RadioHead/) (which was used in very early versions of this project). It has four conceptual layers.
### A note about protocol buffers
Because we want our devices to work across various vendors and implementations, we use [Protocol Buffers](https://github.com/meshtastic/Meshtastic-protobufs) pervasively. For information on how the protocol buffers are used wrt API clients see [sw-design](sw-design.md), for purposes of this document you mostly only
need to consider the MeshPacket and Subpacket message types.
### Layer 1: Non reliable zero hop messaging
This layer is conventional non-reliable lora packet transmission. The transmitted packet has the following representation on the ether:
- A 32 bit LORA preamble (to allow receiving radios to synchronize clocks and start framing). We use a longer than minimum (8 bit) preamble to maximize the amount of time the LORA receivers can stay asleep, which dramatically lowers power consumption.
After the preamble the 16 byte packet header is transmitted. This header is described directly by the PacketHeader class in the C++ source code. But indirectly it matches the first portion of the "MeshPacket" protobuf definition. But notably: this portion of the packet is sent directly as the following 16 bytes (rather than using the protobuf encoding). We do this to both save airtime and to allow receiving radio hardware the option of filtering packets before even waking the main CPU.
- to (4 bytes): the unique NodeId of the destination (or 0xffffffff for NodeNum_BROADCAST)
- from (4 bytes): the unique NodeId of the sender)
- id (4 bytes): the unique (wrt the sending node only) packet ID number for this packet. We use a large (32 bit) packet ID to ensure there is enough unique state to protect any encrypted payload from attack.
- flags (4 bytes): Only a few bits are are currently used - 3 bits for for the "HopLimit" (see below) and 1 bit for "WantAck"
After the packet header the actual packet is placed onto the the wire. These bytes are merely the encrypted packed protobuf encoding of the SubPacket protobuf. A full description of our encryption is available in [crypto](crypto.md). It is worth noting that only this SubPacket is encrypted, headers are not. Which leaves open the option of eventually allowing nodes to route packets without knowing the keys used to encrypt.
NodeIds are constructed from the bottom four bytes of the macaddr of the bluetooth address. Because the OUI is assigned by the IEEE and we currently only support a few CPU manufacturers, the upper byte is defacto guaranteed unique for each vendor. The bottom 3 bytes are guaranteed unique by that vendor.
To prevent collisions all transmitters will listen before attempting to send. If they hear some other node transmitting, they will reattempt transmission in x milliseconds. This retransmission delay is random between FIXME and FIXME (these two numbers are currently hardwired, but really should be scaled based on expected packet transmission time at current channel settings).
### Layer 2: Reliable zero hop messaging
This layer adds reliable messaging between the node and its immediate neighbors (only).
The default messaging provided by layer-1 is extended by setting the "want-ack" flag in the MeshPacket protobuf. If want-ack is set the following documentation from mesh.proto applies:
"""This packet is being sent as a reliable message, we would prefer it to arrive
at the destination. We would like to receive a ack packet in response.
Broadcasts messages treat this flag specially: Since acks for broadcasts would
rapidly flood the channel, the normal ack behavior is suppressed. Instead,
the original sender listens to see if at least one node is rebroadcasting this
packet (because naive flooding algorithm). If it hears that the odds (given
typical LoRa topologies) the odds are very high that every node should
eventually receive the message. So FloodingRouter.cpp generates an implicit
ack which is delivered to the original sender. If after some time we don't
hear anyone rebroadcast our packet, we will timeout and retransmit, using the
regular resend logic."""
If a transmitting node does not receive an ACK (or a NAK) packet within FIXME milliseconds, it will use layer-1 to attempt a retransmission of the sent packet. A reliable packet (at this 'zero hop' level) will be resent a maximum of three times. If no ack or nak has been received by then the local node will internally generate a nak (either for local consumption or use by higher layers of the protocol).
### Layer 3: (Naive) flooding for multi-hop messaging
Given our use-case for the initial release, most of our protocol is built around [flooding](<https://en.wikipedia.org/wiki/Flooding_(computer_networking)>). The implementation is currently 'naive' - i.e. it doesn't try to optimize flooding other than abandoning retransmission once we've seen a nearby receiver has acked the packet. Therefore, for each source packet up to N retransmissions might occur (if there are N nodes in the mesh).
Each node in the mesh, if it sees a packet on the ether with HopLimit set to a value other than zero, it will decrement that HopLimit and attempt retransmission on behalf of the original sending node.
### Layer 4: DSR for multi-hop unicast messaging
This layer is not yet fully implemented (and not yet used). But eventually (if we stay with our own transport rather than switching to QMesh or Reticulum)
we will use conventional DSR for unicast messaging. Currently (even when not requiring 'broadcasts') we send any multi-hop unicasts as 'broadcasts' so that we can
leverage our (functional) flooding implementation. This is suboptimal but it is a very rare use-case, because the odds are high that most nodes (given our small networks and 'hiking' use case) are within a very small number of hops. When any node witnesses an ack for a packet, it will realize that it can abandon its own
broadcast attempt for that packet.
## Misc notes on remaining tasks
This section is currently poorly formatted, it is mostly a mere set of todo lists and notes for @geeksville during his initial development. After release 1.0 ideas for future optimization include:
- Make flood-routing less naive (because we have GPS and radio signal strength as heuristics to avoid redundant retransmissions)
- If nodes have been user marked as 'routers', preferentially do flooding via those nodes
- Fully implement DSR to improve unicast efficiency (or switch to QMesh/Reticulum as these projects mature)
great source of papers and class notes: http://www.cs.jhu.edu/~cs647/
flood routing improvements
@@ -19,20 +89,21 @@ reliable messaging tasks (stage one for DSR):
- DONE once an ack comes in, remove the packet from the retry list and deliver the ack to the original sender
- DONE after three retries, deliver a no-ack packet to the original sender (i.e. the phone app or mesh router service)
- DONE test one hop ack/nak with the python framework
- Do stress test with acks
- DONE Do stress test with acks
dsr tasks
- oops I might have broken message reception
- DONE oops I might have broken message reception
- DONE Don't use broadcasts for the network pings (close open github issue)
- DONE add ignoreSenders to radioconfig to allow testing different mesh topologies by refusing to see certain senders
- test multihop delivery with the python framework
- DONE test multihop delivery with the python framework
optimizations / low priority:
- read this [this](http://pages.cs.wisc.edu/~suman/pubs/nadv-mobihoc05.pdf) paper and others and make our naive flood routing less naive
- read @cyclomies long email with good ideas on optimizations and reply
- Remove NodeNum assignment algorithm (now that we use 4 byte node nums)
- make android app warn if firmware is too old or too new to talk to
- DONE Remove NodeNum assignment algorithm (now that we use 4 byte node nums)
- DONE make android app warn if firmware is too old or too new to talk to
- change nodenums and packetids in protobuf to be fixed32
- low priority: think more careful about reliable retransmit intervals
- make ReliableRouter.pending threadsafe
@@ -145,23 +216,3 @@ look into the literature for this idea specifically.
build the most recent version of reality, and if some nodes are too far, then nodes closer in will eventually forward their changes to the distributed db.
- construct non ambigious rules for who broadcasts to request db updates. ideally the algorithm should nicely realize node X can see most other nodes, so they should just listen to all those nodes and minimize the # of broadcasts. the distributed picture of nodes rssi could be useful here?
- possibly view the BLE protocol to the radio the same way - just a process of reconverging the node/msgdb database.
# Old notes
FIXME, merge into the above:
good description of batman protocol: https://www.open-mesh.org/projects/open-mesh/wiki/BATMANConcept
interesting paper on lora mesh: https://portal.research.lu.se/portal/files/45735775/paper.pdf
It seems like DSR might be the algorithm used by RadioheadMesh. DSR is described in https://tools.ietf.org/html/rfc4728
Use naive flooding at first (FIXME - do some math for a 20 node, 3 hop mesh. A single flood will require a max of 20 messages sent)
Then move to MPR later (http://www.olsr.org/docs/report_html/node28.html). Use altitude and location as heursitics in selecting the MPR set
compare to db sync algorithm?
what about never flooding gps broadcasts. instead only have them go one hop in the common case, but if any node X is looking at the position of Y on their gui, then send a unicast to Y asking for position update. Y replies.
If Y were to die, at least the neighbor nodes of Y would have their last known position of Y.
Some files were not shown because too many files have changed in this diff
Show More
Reference in New Issue
Block a user
Blocking a user prevents them from interacting with repositories, such as opening or commenting on pull requests or issues. Learn more about blocking a user.