portuino now kinda works with the pinetab lora USB module.

still need to add an AEX256 impl for the linux port and optimize a bit

src/portduino/PortduinoGlue.cpp

@@ -37,6 +37,52 @@ CryptoEngine *crypto = new CryptoEngine();
 
 void updateBatteryLevel(uint8_t level) NOT_IMPLEMENTED("updateBatteryLevel");
 
+#include <assert.h>
+#include "mesh/RF95Interface.h"
+
+/** Dear pinetab hardware geeks!
+ * 
+ * The current pinetab lora module has a slight bug.  The ch341 part only provides ISR assertions on edges.
+ * This makes sense because USB interrupts happen through fast/repeated special irq urbs that are constantly
+ * chattering on the USB bus.
+ * 
+ * But this isn't sufficient for level triggered ISR sources like the sx127x radios.  The common way that seems to
+ * be addressed by cs341 users is to **always** connect the INT# (pin 26 on the ch341f) signal to one of the GPIO signals
+ * on the part.  I'd recommend connecting that LORA_DIO0/INT# line to pin 19 (data 4) on the pinetab board.  This would
+ * provide an efficent mechanism so that the (kernel) code in the cs341 driver that I've slightly hacked up to see the
+ * current state of LORA_DIO0.  Without that access, I can't know if the interrupt is still pending - which would create
+ * race conditions in packet handling.  
+ * 
+ * My workaround is to poll the status register internally to the sx127x.  Which is expensive because it involves a number of
+ * i2c transactions and many trips back and forth between kernel and my userspace app.  I think shipping the current version
+ * of the pinetab lora device would be fine because I can poll slowly (because lora is slow).  But if you ever have cause to
+ * rev this board.  I highly encourage this small change.
+ * 
+ * Btw - your little "USB lora dongle" is really neat.  I encourage you to sell it, because even non pinetab customers could
+ * use it to easily add lora to rasberry pi, desktop pcs etc...
+ * 
+ * Porduino helper class to do this i2c based polling:
+ */
+class R595PolledIrqPin : public GPIOPin {
+public:
+    R595PolledIrqPin() : GPIOPin(LORA_DIO0, "LORA_DIO0") {}
+
+    /// Read the low level hardware for this pin
+    virtual PinStatus readPinHardware()
+    {
+        if(isrPinStatus < 0)
+            return LOW; // No interrupt handler attached, don't bother polling i2c right now
+        else {
+            extern RadioInterface *rIf; // FIXME, temporary hack until we know if we need to keep this 
+
+            assert(rIf);
+            RF95Interface *rIf95 = static_cast<RF95Interface *>(rIf);
+            bool p = rIf95->isIRQPending();
+            // log(SysGPIO, LogDebug, "R595PolledIrqPin::readPinHardware(%s, %d, %d)", getName(), getPinNum(), p);
+            return p ? HIGH : LOW;
+        }
+    }
+};
 
 
 /** apps run under portduino can optionally define a portduinoSetup() to 
@@ -45,7 +91,7 @@ void updateBatteryLevel(uint8_t level) NOT_IMPLEMENTED("updateBatteryLevel");
  */
 void  portduinoSetup() {
   printf("Setting up Meshtastic on Porduino...\n");
-  gpioBind((new SimGPIOPin(LORA_DIO0, "LORA_DIO0")));
-  gpioBind((new SimGPIOPin(LORA_RESET, "LORA_RESET")));
+  gpioBind(new R595PolledIrqPin());
+  // gpioBind((new SimGPIOPin(LORA_RESET, "LORA_RESET")));
   gpioBind((new SimGPIOPin(RF95_NSS, "RF95_NSS"))->setSilent());
 }