mqtt design progress

docs/software/remote-hardware-service.md

@@ -0,0 +1,23 @@
+# Remote Hardware Service
+
+FIXME - the following are a collection of notes moved from elsewhere.  We need to refactor these notes into actual documentation on the remote-hardware/gpio service.
+
+### 1.7.2. New 'no-code-IOT' mini-app
+
+Add a new 'remote GPIO/serial port/SPI/I2C access' mini-app. This new standard app would use the MQTT messaging layer to let users (developers that don't need to write device code) do basic (potentially dangerous) operations remotely.
+
+#### 1.7.2.1. Supported operations in the initial release
+
+Initially supported features for no-code-IOT.
+
+- Set any GPIO
+- Read any GPIO
+
+#### 1.7.2.2. Supported operations eventually
+
+General ideas for no-code IOT.
+
+- Subscribe for notification of GPIO input status change (i.e. when pin goes low, send my app a message)
+- Write/read N bytes over I2C/SPI bus Y (as one atomic I2C/SPI transaction)
+- Send N bytes out serial port Z
+- Subscribe for notification for when regex X matches the bytes that were received on serial port Z