Initial support for Flex LoRa and GNSS updates over UART

Author: PaulZC

Firmware/RTK_Everywhere/Begin.ino

@@ -161,6 +161,7 @@ void identifyBoard()
             productVariant = RTK_POSTCARD;
 
 #ifndef NOT_FACET_FLEX
+        systemPrintln("<<<<<<<<<< !!!!!!!!!! FLEX FORCED !!!!!!!!!! >>>>>>>>>>");
         productVariant = RTK_FLEX; // TODO remove once v1.1 Flex has ID resistors
 #endif
     }
@@ -1129,27 +1130,8 @@ void beginGnssUart()
     }
 }
 
-// Assign GNSS UART interrupts to the core that started the task. See:
-// https://github.com/espressif/arduino-esp32/issues/3386
-void pinGnssUartTask(void *pvParameters)
+void forceGnssCommunicationRate(uint32_t &platformGnssCommunicationRate)
 {
-    // Start notification
-    if (settings.printTaskStartStop)
-        systemPrintln("Task pinGnssUartTask started");
-
-    if (serialGNSS == nullptr)
-        serialGNSS = new HardwareSerial(2); // Use UART2 on the ESP32 for communication with the GNSS module
-
-    serialGNSS->setRxBufferSize(settings.uartReceiveBufferSize);
-    serialGNSS->setTimeout(settings.serialTimeoutGNSS); // Requires serial traffic on the UART pins for detection
-
-    if (pin_GnssUart_RX == -1 || pin_GnssUart_TX == -1)
-        reportFatalError("Illegal UART pin assignment.");
-
-    uint32_t platformGnssCommunicationRate =
-        settings.dataPortBaud; // Default to 230400bps for ZED. This limits GNSS fixes at 4Hz but allows SD buffer to be
-                               // reduced to 6k.
-
     if (productVariant == RTK_TORCH)
     {
         // Override user setting. Required because beginGnssUart() is called before beginBoard().
@@ -1178,6 +1160,29 @@ void pinGnssUartTask(void *pvParameters)
             platformGnssCommunicationRate = 115200;
         }
     }
+}
+// Assign GNSS UART interrupts to the core that started the task. See:
+// https://github.com/espressif/arduino-esp32/issues/3386
+void pinGnssUartTask(void *pvParameters)
+{
+    // Start notification
+    if (settings.printTaskStartStop)
+        systemPrintln("Task pinGnssUartTask started");
+
+    if (serialGNSS == nullptr)
+        serialGNSS = new HardwareSerial(2); // Use UART2 on the ESP32 for communication with the GNSS module
+
+    serialGNSS->setRxBufferSize(settings.uartReceiveBufferSize);
+    serialGNSS->setTimeout(settings.serialTimeoutGNSS); // Requires serial traffic on the UART pins for detection
+
+    if (pin_GnssUart_RX == -1 || pin_GnssUart_TX == -1)
+        reportFatalError("Illegal UART pin assignment.");
+
+    uint32_t platformGnssCommunicationRate =
+        settings.dataPortBaud; // Default to 230400bps for ZED. This limits GNSS fixes at 4Hz but allows SD buffer to be
+                               // reduced to 6k.
+
+    forceGnssCommunicationRate(platformGnssCommunicationRate);
 
     serialGNSS->begin(platformGnssCommunicationRate, SERIAL_8N1, pin_GnssUart_RX,
                       pin_GnssUart_TX); // Start UART on platform dependent pins for SPP. The GNSS will be

Firmware/RTK_Everywhere/Display.ino

@@ -3288,3 +3288,30 @@ void displayWebConfig(std::vector<iconPropertyBlinking> &iconPropertyList)
 
     printTextCenter(myIP, yPos, QW_FONT_5X7, 1, false);
 }
+
+// Show GNSS update - button exit
+void paintGnssUpdate()
+{
+    paintGenericUpdate("GNSS");
+}
+void paintLoRaUpdate()
+{
+    paintGenericUpdate("LoRa");
+}
+void paintGenericUpdate(const char *device)
+{
+    if (online.display)
+    {
+        oled->erase(); // Clear the display's internal buffer
+        int yPos = (oled->getHeight() - 38) / 2;
+        uint8_t fontHeight = 8;
+        printTextCenter(device, yPos, QW_FONT_5X7, 1, false); // text, y, font type, kerning, inverted
+        yPos = yPos + fontHeight + 1;
+        printTextCenter("Update", yPos, QW_FONT_5X7, 1, false);
+        yPos = yPos + fontHeight + 3;
+        printTextCenter("Button", yPos, QW_FONT_5X7, 1, true); // text, y, font type, kerning, inverted
+        yPos = yPos + fontHeight + 1;
+        printTextCenter("To Exit", yPos, QW_FONT_5X7, 1, true);
+        oled->display(); // Push internal buffer to display
+    }
+}

Firmware/RTK_Everywhere/GNSS.ino

@@ -142,7 +142,10 @@ void gnssDetectReceiverType()
 
     // TODO remove after testing, force retest on each boot
     // Note: with this in place, the X5 detection will take a lot longer due to the baud rate change
-    settings.detectedGnssReceiver = GNSS_RECEIVER_UNKNOWN;
+#ifndef NOT_FACET_FLEX
+    systemPrintln("<<<<<<<<<< !!!!!!!!!! FLEX FORCED !!!!!!!!!! >>>>>>>>>>");
+    //settings.detectedGnssReceiver = GNSS_RECEIVER_UNKNOWN; // This may be causing weirdness on the LG290P. Commenting for now
+#endif
 
     // Start auto-detect if NVM is not yet set
     if (settings.detectedGnssReceiver == GNSS_RECEIVER_UNKNOWN)
@@ -243,4 +246,179 @@ void gnssReset()
     {
         digitalWrite(pin_GNSS_Reset, LOW); // Tell LG290P to reset
     }
-}
+}
+
+//----------------------------------------
+// Force UART connection to GNSS for firmware update on the next boot by special file in
+// LittleFS
+//----------------------------------------
+bool createGNSSPassthrough()
+{
+    return createPassthrough("/updateGnssFirmware.txt");
+}
+bool createPassthrough(const char *filename)
+{
+    if (online.fs == false)
+        return false;
+
+    if (LittleFS.exists(filename))
+    {
+        if (settings.debugGnss)
+            systemPrintf("LittleFS %s already exists\r\n", filename);
+        return true;
+    }
+
+    File updateUm980Firmware = LittleFS.open(filename, FILE_WRITE);
+    updateUm980Firmware.close();
+
+    if (LittleFS.exists(filename))
+        return true;
+
+    if (settings.debugGnss)
+        systemPrintf("Unable to create %s on LittleFS\r\n", filename);
+    return false;
+}
+
+//----------------------------------------
+void gnssFirmwareBeginUpdate()
+{
+    // Note: UM980 needs its own dedicated update function, due to the T@ and bootloader trigger
+
+    // Note: gnssFirmwareBeginUpdate is called during setup, after identify board. I2C, gpio expanders, buttons
+    //  and display have all been initialized. But, importantly, the UARTs have not yet been started.
+    //  This makes our job much easier...
+
+    // NOTE: X20P may expect a baud rate change during the update. We may need to force 9600 baud. TODO
+
+    // Flag that we are in direct connect mode. Button task will gnssFirmwareRemoveUpdate and exit
+    inDirectConnectMode = true;
+
+    // Note: we can't call gnssFirmwareRemoveUpdate() here as closing Tera Term will reset the ESP32,
+    //       returning the firmware to normal operation...
+
+    // Paint GNSS Update
+    paintGnssUpdate();
+
+    // Stop all UART tasks. Redundant
+    tasksStopGnssUart();
+
+    uint32_t serialBaud = 115200;
+
+    forceGnssCommunicationRate(serialBaud); // On Flex, must be called after gnssDetectReceiverType
+
+    systemPrintln();
+    systemPrintf("Entering GNSS direct connect for firmware update and configuration. Disconnect this terminal "
+                  "connection. Use the GNSS manufacturer software "
+                  "to update the firmware. Baudrate: %dbps. Press the %s button to return "
+                  "to normal operation.\r\n", serialBaud, present.button_mode ? "mode" : "power");
+    systemFlush();
+
+    Serial.end(); // We must end before we begin otherwise the UART settings are corrupted
+    Serial.begin(serialBaud);
+
+    if (serialGNSS == nullptr)
+        serialGNSS = new HardwareSerial(2); // Use UART2 on the ESP32 for communication with the GNSS module
+
+    serialGNSS->setRxBufferSize(settings.uartReceiveBufferSize);
+    serialGNSS->setTimeout(settings.serialTimeoutGNSS); // Requires serial traffic on the UART pins for detection
+
+    // This is OK for Flex too. We're using the main GNSS pins.
+    serialGNSS->begin(serialBaud, SERIAL_8N1, pin_GnssUart_RX, pin_GnssUart_TX);
+
+    // // On Flex with the LG290P, it may be wise to disable message output on UART1 first?
+    // if ((productVariant == RTK_FLEX) && present.gnss_lg290p)
+    // {
+    //     // GNSS has not been begun, so we need to send the command manually
+    //     serialGNSS->println("$PQTMCFGPROT,W,1,1,00000000,00000000*38");
+    //     delay(100);
+    //     serialGNSS->println("$PQTMCFGPROT,W,1,1,00000000,00000000*38");
+    //     delay(100);
+    //     while (serialGNSS->available())
+    //         serialGNSS->read(); // Soak up any residual messages
+    // }
+
+    // Echo everything to/from GNSS
+    while (1)
+    {
+        static unsigned long lastSerial = millis(); // Temporary fix for buttonless Flex
+
+        if (Serial.available()) // Note: use if, not while
+        {
+            serialGNSS->write(Serial.read());
+            lastSerial = millis();
+        }
+
+        if (serialGNSS->available()) // Note: use if, not while
+            Serial.write(serialGNSS->read());
+
+        // Button task will gnssFirmwareRemoveUpdate and restart
+        
+        // Temporary fix for buttonless Flex. TODO - remove
+        if ((productVariant == RTK_FLEX) && (millis() > (lastSerial + 30000)))
+        {
+                // Beep to indicate exit
+                beepOn();
+                delay(300);
+                beepOff();
+                delay(100);
+                beepOn();
+                delay(300);
+                beepOff();
+
+                gnssFirmwareRemoveUpdate();
+
+                systemPrintln("Exiting direct connection (passthrough) mode");
+                systemFlush(); // Complete prints
+
+                ESP.restart();
+        }
+    }
+}
+
+//----------------------------------------
+// Check if direct connection file exists
+//----------------------------------------
+bool gnssFirmwareCheckUpdate()
+{
+    return gnssFirmwareCheckUpdateFile("/updateGnssFirmware.txt");
+}
+bool gnssFirmwareCheckUpdateFile(const char *filename)
+{
+    if (online.fs == false)
+        return false;
+
+    if (LittleFS.exists(filename))
+    {
+        if (settings.debugGnss)
+            systemPrintf("LittleFS %s exists\r\n", filename);
+
+        // We do not remove the file here. See removeupdateUm980Firmware().
+
+        return true;
+    }
+
+    return false;
+}
+
+//----------------------------------------
+// Remove direct connection file
+//----------------------------------------
+void gnssFirmwareRemoveUpdate()
+{
+    return gnssFirmwareRemoveUpdateFile("/updateGnssFirmware.txt");
+}
+void gnssFirmwareRemoveUpdateFile(const char *filename)
+{
+    if (online.fs == false)
+        return;
+
+    if (LittleFS.exists(filename))
+    {
+        if (settings.debugGnss)
+            systemPrintf("Removing %s\r\n", filename);
+
+        LittleFS.remove(filename);
+    }
+}
+
+//----------------------------------------