feat: Reliable GPS on all RAK WisBlock GPS boards (RAK12500 ublox + RAK12501 Quectel)

examples/companion_radio/ui-new/UITask.cpp

@@ -308,22 +308,37 @@ class HomeScreen : public UIScreen {
       display.drawTextLeftAlign(0, y, buf);
       if (nmea == NULL) {
         y = y + 12;
-        display.drawTextLeftAlign(0, y, "Can't access GPS");
+        display.drawTextLeftAlign(0, y, "No GPS detected");
       } else {
-        strcpy(buf, nmea->isValid()?"fix":"no fix");
+        if (!gps_state) {
+          strcpy(buf, "off");
+        } else switch (nmea->getFixType()) {
+          case 3:  strcpy(buf, "3D"); break;
+          case 2:  strcpy(buf, "2D"); break;
+          default: strcpy(buf, "no fix"); break;
+        }
         display.drawTextRightAlign(display.width()-1, y, buf);
         y = y + 12;
         display.drawTextLeftAlign(0, y, "sat");
         sprintf(buf, "%d", nmea->satellitesCount());
         display.drawTextRightAlign(display.width()-1, y, buf);
         y = y + 12;
+        bool has_pos = (nmea->getLatitude() != 0 || nmea->getLongitude() != 0);
         display.drawTextLeftAlign(0, y, "pos");
-        sprintf(buf, "%.4f %.4f",
-          nmea->getLatitude()/1000000., nmea->getLongitude()/1000000.);
+        if (has_pos) {
+          sprintf(buf, "%.4f %.4f",
+            nmea->getLatitude()/1000000., nmea->getLongitude()/1000000.);
+        } else {
+          strcpy(buf, "---");
+        }
         display.drawTextRightAlign(display.width()-1, y, buf);
         y = y + 12;
         display.drawTextLeftAlign(0, y, "alt");
-        sprintf(buf, "%.2f", nmea->getAltitude()/1000.);
+        if (has_pos) {
+          sprintf(buf, "%.2f", nmea->getAltitude()/1000.);
+        } else {
+          strcpy(buf, "---");
+        }
         display.drawTextRightAlign(display.width()-1, y, buf);
         y = y + 12;
       }

examples/companion_radio/ui-tiny/UITask.cpp

@@ -267,7 +267,7 @@ class HomeScreen : public UIScreen {
       display.drawTextLeftAlign(0, y, buf);
       if (nmea == NULL) {
         // y = y + 8;
-        display.drawTextLeftAlign(0, y, "Can't access GPS");
+        display.drawTextLeftAlign(0, y, "No GPS detected");
       } else {
         if (!gps_state || !nmea->isValid()) {
             strcpy(buf, "no fix");

src/helpers/sensors/EnvironmentSensorManager.cpp

@@ -165,7 +165,9 @@ static RAK12035_SoilMoisture RAK12035;
 #endif
 
 #ifdef RAK_WISBLOCK_GPS
-static uint32_t gpsResetPin = 0;
+// -1 = no enable pin; out-of-range values are no-ops in pinMode/digitalWrite,
+// while 0 would be a real GPIO (P0.00 = LFXO crystal on nRF52)
+static uint32_t gpsResetPin = -1;
 static bool i2cGPSFlag = false;
 static bool serialGPSFlag = false;
 #ifndef TELEM_RAK12500_ADDRESS
@@ -181,28 +183,71 @@ class RAK12500LocationProvider : public LocationProvider {
   int _sats = 0;
   long _epoch = 0;
   bool _fix = false;
+  uint8_t _fixType = 0;
+  unsigned long _next_poll = 0;
 public:
   long getLatitude() override { return _lat; }
   long getLongitude() override { return _lng; }
   long getAltitude() override { return _alt; }
   long satellitesCount() override { return _sats; }
   bool isValid() override { return _fix; }
+  uint8_t getFixType() override { return _fixType; }
   long getTimestamp() override { return _epoch; }
   void sendSentence(const char * sentence) override { }
   void reset() override { }
   void begin() override { }
   void stop() override { }
   void loop() override {
-    if (ublox_GNSS.getGnssFixOk(8)) {
-      _fix = true;
-      _lat = ublox_GNSS.getLatitude(2) / 10;
-      _lng = ublox_GNSS.getLongitude(2) / 10;
-      _alt = ublox_GNSS.getAltitude(2);
-      _sats = ublox_GNSS.getSIV(2);
+    // Throttle the I²C poll to ~1 Hz. The getXxx() calls below each issue a
+    // synchronous ublox poll that blocks up to its maxWait; the GNSS solution only
+    // updates at the 1 Hz navigation rate (setMeasurementRate(1000)), so polling on
+    // every main-loop iteration just burns the loop on redundant I²C round-trips —
+    // that stall is what made the AIN1 button sluggish and drop double-clicks.
+    // Polling once per nav epoch keeps the fix/time fresh while leaving the loop
+    // free for button sampling the rest of the time.
+    if (millis() < _next_poll) {
+      return;
+    }
+    _next_poll = millis() + 1000;
+
+    // The numeric arg is maxWait (ms) for the I²C poll, not a field index.
+    // The previous 2/8 ms values were below the ublox response window, so polls
+    // routinely timed out and returned stale/garbage PVT data (observed: random
+    // wrong-hemisphere longitudes despite getGnssFixOk() returning true).
+    // 250 ms is a ceiling; a responsive module returns well before that. getPVT()
+    // does the single poll here, then every getter reads that same cached packet
+    // (passing no maxWait, so they never re-poll). Gating all reads on getPVT()
+    // succeeding matters: if the poll times out, a getter with a stale cache would
+    // otherwise fire its own poll at the library default (~1100 ms) and stall hard.
+    if (!ublox_GNSS.getPVT(250)) {
+      return;   // no response this tick — keep last reported values
+    }
+
+    // Show the position EAGERLY: as soon as there's a real 2D/3D solution (SIV>0,
+    // fixType>=2) with valid coords, display it -- don't wait for gnssFixOk, which can
+    // take up to ~30 s to assert. Coords must be present (0/0 is the "no data" value) and
+    // in range: the module emits 0/0 and ~999deg junk while cold/re-tracking, so rejecting
+    // those keeps _lat/_lng at 0 (-> "---"). Telemetry is stricter: _fix (= isValid()) only
+    // goes true once gnssFixOk passes on a full 3D fix, and node_lat is gated on isValid()
+    // -- so the screen can show a settling fix while we withhold a loose one from the mesh.
+    _sats = ublox_GNSS.getSIV();           // valid without a fix -- shows acquisition progress
+    long lat = ublox_GNSS.getLatitude() / 10;
+    long lng = ublox_GNSS.getLongitude() / 10;
+    uint8_t ft = (_sats > 0) ? ublox_GNSS.getFixType() : 0;
+    bool coords_ok = (lat != 0 || lng != 0) &&
+                     lat >= -90000000  && lat <= 90000000 &&     // +/-90 deg  (1e6 scale)
+                     lng >= -180000000 && lng <= 180000000;      // +/-180 deg
+    if (ft >= 2 && coords_ok) {
+      _fixType = ft;                        // 2 or 3 -- shown on screen with the coords
+      _lat = lat;
+      _lng = lng;
+      _alt = ublox_GNSS.getAltitudeMSL();   // height above mean sea level, not ellipsoid
+      _fix = (ft == 3 && ublox_GNSS.getGnssFixOk());   // isValid()/telemetry: accuracy-OK 3D only
     } else {
+      _fixType = 0;                         // no usable fix -> "no fix" + held/--- position
       _fix = false;
     }
-    _epoch = ublox_GNSS.getUnixEpoch(2);
+    _epoch = ublox_GNSS.getUnixEpoch();
   }
   bool isEnabled() override { return true; }
 };
@@ -787,16 +832,25 @@ void EnvironmentSensorManager::rakGPSInit(){
   //search for the correct IO standby pin depending on socket used
   if(gpsIsAwake(WB_IO2)){
   }
-  else if(gpsIsAwake(WB_IO4)){
-  }
-  else if(gpsIsAwake(WB_IO5)){
-  }
-  else{
-    MESH_DEBUG_PRINTLN("No GPS found");
-    gps_active = false;
-    gps_detected = false;
-    Serial1.end();
-    return;
+  else {
+    // WB_IO2 controls the 3V3_S switched peripheral rail on these RAK boards.
+    // gpsIsAwake() leaves the pin as INPUT on failure, which drops the rail and
+    // takes I²C peripherals (RTC, display, the GPS itself) down with it.
+    // Restore it before probing other sockets.
+    pinMode(WB_IO2, OUTPUT);
+    digitalWrite(WB_IO2, HIGH);
+
+    if(gpsIsAwake(WB_IO4)){
+    }
+    else if(gpsIsAwake(WB_IO5)){
+    }
+    else{
+      MESH_DEBUG_PRINTLN("No GPS found");
+      gps_active = false;
+      gps_detected = false;
+      Serial1.end();
+      return;
+    }
   }
 
   #ifndef FORCE_GPS_ALIVE // for use with repeaters, until GPS toggle is implimented
@@ -837,7 +891,7 @@ bool EnvironmentSensorManager::gpsIsAwake(uint8_t ioPin){
   } else if (Serial1.available()) {
     MESH_DEBUG_PRINTLN("Serial GPS init correctly and is turned on");
 #ifdef PIN_GPS_EN
-    if(PIN_GPS_EN){
+    if(PIN_GPS_EN >= 0){
       gpsResetPin = PIN_GPS_EN;
     }
 #endif
@@ -856,8 +910,23 @@ bool EnvironmentSensorManager::gpsIsAwake(uint8_t ioPin){
 void EnvironmentSensorManager::start_gps() {
   gps_active = true;
   #ifdef RAK_WISBLOCK_GPS
-    pinMode(gpsResetPin, OUTPUT);
-    digitalWrite(gpsResetPin, HIGH);
+    #if defined(PIN_GPS_EN) && (PIN_GPS_EN >= 0)
+      pinMode(gpsResetPin, OUTPUT);
+      digitalWrite(gpsResetPin, HIGH);   // dedicated GPS enable pin
+    #else
+      // No dedicated enable pin: gpsResetPin is the shared 3V3_S rail (WB_IO2),
+      // which also powers the RTC/boost and must stay HIGH. Wake the receiver in
+      // software instead of touching the rail.
+      if (i2cGPSFlag) {
+        // UBX-CFG-RST "controlled GNSS start": resume the receiver stopped below.
+        static const uint8_t ubxGnssStart[] = {0xB5,0x62,0x06,0x04,0x04,0x00,0x00,0x00,0x09,0x00,0x17,0x76};
+        Wire.beginTransmission((uint8_t)TELEM_RAK12500_ADDRESS);
+        Wire.write(ubxGnssStart, sizeof(ubxGnssStart));
+        Wire.endTransmission();
+      } else if (serialGPSFlag) {
+        Serial1.write((uint8_t)0xFF);                              // wake MTK/Quectel from standby
+      }
+    #endif
     return;
   #endif
 
@@ -872,8 +941,25 @@ void EnvironmentSensorManager::start_gps() {
 void EnvironmentSensorManager::stop_gps() {
   gps_active = false;
   #ifdef RAK_WISBLOCK_GPS
-    pinMode(gpsResetPin, OUTPUT);
-    digitalWrite(gpsResetPin, LOW);
+    #if defined(PIN_GPS_EN) && (PIN_GPS_EN >= 0)
+      pinMode(gpsResetPin, OUTPUT);
+      digitalWrite(gpsResetPin, LOW);   // dedicated GPS enable pin
+    #else
+      // No dedicated enable pin: gpsResetPin is the shared 3V3_S rail (WB_IO2),
+      // which also powers the RTC/boost and must stay HIGH. Don't drop it; put
+      // the receiver into software low-power instead (rail/RTC stay up, warm-start).
+      if (i2cGPSFlag) {
+        // UBX-CFG-RST "controlled GNSS stop": stops RF/tracking but keeps the host
+        // interface alive, so it restarts reliably over I2C. (PMREQ backup only wakes
+        // on EXTINT/UART, not I2C -- confirmed dead on this hardware.)
+        static const uint8_t ubxGnssStop[] = {0xB5,0x62,0x06,0x04,0x04,0x00,0x00,0x00,0x08,0x00,0x16,0x74};
+        Wire.beginTransmission((uint8_t)TELEM_RAK12500_ADDRESS);
+        Wire.write(ubxGnssStop, sizeof(ubxGnssStop));
+        Wire.endTransmission();
+      } else if (serialGPSFlag) {
+        Serial1.println("$PMTK161,0*28");     // Quectel/MTK standby
+      }
+    #endif
     return;
   #endif
 
@@ -890,6 +976,7 @@ void EnvironmentSensorManager::loop() {
 
   #if ENV_INCLUDE_GPS
   static unsigned long next_gps_update = 0;
+  static uint8_t gps_debug_skip = 0;   // throttle: print roughly every 10th update tick
   if (gps_active) {
     _location->loop();
   }
@@ -900,17 +987,21 @@ void EnvironmentSensorManager::loop() {
     if ((i2cGPSFlag || serialGPSFlag) && _location->isValid()) {
       node_lat = ((double)_location->getLatitude())/1000000.;
       node_lon = ((double)_location->getLongitude())/1000000.;
-      MESH_DEBUG_PRINTLN("lat %f lon %f", node_lat, node_lon);
       node_altitude = ((double)_location->getAltitude()) / 1000.0;
-      MESH_DEBUG_PRINTLN("lat %f lon %f alt %f", node_lat, node_lon, node_altitude);
+      if (gps_debug_skip-- == 0) {
+        gps_debug_skip = 9;
+        MESH_DEBUG_PRINTLN("lat %f lon %f alt %f", node_lat, node_lon, node_altitude);
+      }
     }
     #else
     if (_location->isValid()) {
       node_lat = ((double)_location->getLatitude())/1000000.;
       node_lon = ((double)_location->getLongitude())/1000000.;
-      MESH_DEBUG_PRINTLN("lat %f lon %f", node_lat, node_lon);
       node_altitude = ((double)_location->getAltitude()) / 1000.0;
-      MESH_DEBUG_PRINTLN("lat %f lon %f alt %f", node_lat, node_lon, node_altitude);
+      if (gps_debug_skip-- == 0) {
+        gps_debug_skip = 9;
+        MESH_DEBUG_PRINTLN("lat %f lon %f alt %f", node_lat, node_lon, node_altitude);
+      }
     }
     #endif
     }

src/helpers/sensors/EnvironmentSensorManager.h

@@ -37,7 +37,9 @@ class EnvironmentSensorManager : public SensorManager {
 public:
   #if ENV_INCLUDE_GPS
   EnvironmentSensorManager(LocationProvider &location): _location(&location){};
-  LocationProvider* getLocationProvider() { return _location; }
+  // NULL when no GPS was detected, so the UI shows "No GPS detected" (CLI: "gps provider
+  // not found") instead of an unfixed-but-present GPS. All consumers already null-check.
+  LocationProvider* getLocationProvider() { return gps_detected ? _location : NULL; }
   #else
   EnvironmentSensorManager(){};
   #endif

src/helpers/sensors/LocationProvider.h

@@ -15,6 +15,7 @@ class LocationProvider {
     virtual long getAltitude() = 0;
     virtual long satellitesCount() = 0;
     virtual bool isValid() = 0;
+    virtual uint8_t getFixType() { return isValid() ? 3 : 0; }  // 0=none, 2=2D, 3=3D; providers may override
     virtual long getTimestamp() = 0;
     virtual void sendSentence(const char * sentence);
     virtual void reset() = 0;

src/helpers/sensors/MicroNMEALocationProvider.h

@@ -110,15 +110,20 @@ public :
     }
 
     void syncTime() override { nmea.clear(); LocationProvider::syncTime(); }
-    long getLatitude() override { return nmea.getLatitude(); }
-    long getLongitude() override { return nmea.getLongitude(); }
+    // MicroNMEA reports lat/lng = 999000000 (999 deg) when there is no fix; map that to 0
+    // (the codebase's no-data value) so the UI shows "---" and node_lat stays 0.
+    long getLatitude() override  { long v = nmea.getLatitude();  return v == 999000000L ? 0 : v; }
+    long getLongitude() override { long v = nmea.getLongitude(); return v == 999000000L ? 0 : v; }
     long getAltitude() override { 
         long alt = 0;
         nmea.getAltitude(alt);
         return alt;
     }
     long satellitesCount() override { return nmea.getNumSatellites(); }
-    bool isValid() override { return nmea.isValid(); }
+    // Require actual coordinates, not just the RMC 'A' status flag: some MTK/Quectel
+    // receivers assert 'A' for seconds before the position is computed -- and MicroNMEA
+    // reports lat==999000000 until then. Without this it'd show "fix" with no coords.
+    bool isValid() override { return nmea.isValid() && nmea.getLatitude() != 999000000L; }
 
     long getTimestamp() override { 
         DateTime dt(nmea.getYear(), nmea.getMonth(),nmea.getDay(),nmea.getHour(),nmea.getMinute(),nmea.getSecond());

variants/rak3401/platformio.ini

@@ -6,13 +6,17 @@ build_flags = ${nrf52_base.build_flags}
   ${sensor_base.build_flags}
   -I variants/rak3401
   -D RAK_3401
+  -D RAK_BOARD
   -D NRF52_POWER_MANAGEMENT
   -D RADIO_CLASS=CustomSX1262
   -D WRAPPER_CLASS=CustomSX1262Wrapper
   -D LORA_TX_POWER=22
   -D SX126X_CURRENT_LIMIT=140
   -D SX126X_RX_BOOSTED_GAIN=1
   -D SX126X_REGISTER_PATCH=1       ; Patch register 0x8B5 for improved RX with SKY66122 FEM
+  -D FORCE_GPS_ALIVE               ; on RAK3401, gpsResetPin ends up = WB_IO2 (kills 3V3_S rail) or
+                                   ; pin 4 (= SX126X_RESET, holds radio in reset). stop_gps() must not run.
+  -D PIN_GPS_EN=-1                 ; -1 = no dedicated GPS enable pin (power is the shared 3V3_S rail), same as rak4631
 build_src_filter = ${nrf52_base.build_src_filter}
   +<../variants/rak3401>
   +<helpers/sensors>

variants/rak3401/variant.h

@@ -188,8 +188,8 @@ static const uint8_t AREF = PIN_AREF;
 // Power is on the controllable 3V3_S rail
 #define PIN_GPS_PPS (17) // Pulse per second input from the GPS
 
-#define PIN_GPS_RX PIN_SERIAL1_RX
-#define PIN_GPS_TX PIN_SERIAL1_TX
+#define PIN_GPS_RX PIN_SERIAL1_TX
+#define PIN_GPS_TX PIN_SERIAL1_RX
 
 #define PIN_GPS_1PPS PIN_GPS_PPS
 #define GPS_BAUD_RATE 9600

variants/rak4631/platformio.ini

@@ -12,8 +12,7 @@ build_flags = ${nrf52_base.build_flags}
   -D NRF52_POWER_MANAGEMENT
   -D PIN_BOARD_SCL=14
   -D PIN_BOARD_SDA=13
-  -D PIN_GPS_TX=PIN_SERIAL1_RX
-  -D PIN_GPS_RX=PIN_SERIAL1_TX
+  -D FORCE_GPS_ALIVE
   -D PIN_GPS_EN=-1
   -D PIN_OLED_RESET=-1
   -D USE_SX1262
@@ -122,7 +121,7 @@ board_upload.maximum_size = 712704
 build_flags =
   ${rak4631.build_flags}
   -I examples/companion_radio/ui-new
-  -D PIN_USER_BTN=9
+  -D PIN_USER_BTN=9  ; P0.09 = IO5: incompatible with Slot D peripherals (e.g. RAK12002 CLKOUT holds it low)
   -D PIN_USER_BTN_ANA=31
   -D DISPLAY_CLASS=SSD1306Display
   -D MAX_CONTACTS=350
@@ -143,7 +142,7 @@ board_upload.maximum_size = 712704
 build_flags =
   ${rak4631.build_flags}
   -I examples/companion_radio/ui-new
-  -D PIN_USER_BTN=9
+  -D PIN_USER_BTN=9  ; P0.09 = IO5: incompatible with Slot D peripherals (e.g. RAK12002 CLKOUT holds it low)
   -D PIN_USER_BTN_ANA=31
   -D DISPLAY_CLASS=SSD1306Display
   -D MAX_CONTACTS=350
@@ -165,7 +164,7 @@ lib_deps =
 extends = rak4631
 build_flags =
   ${rak4631.build_flags}
-  -D PIN_USER_BTN=9
+  -D PIN_USER_BTN=9  ; P0.09 = IO5: incompatible with Slot D peripherals (e.g. RAK12002 CLKOUT holds it low)
   -D PIN_USER_BTN_ANA=31
   -D MAX_CONTACTS=100
   -D MAX_GROUP_CHANNELS=1

variants/rak4631/variant.h

@@ -182,6 +182,9 @@ extern "C"
 #define EXTERNAL_FLASH_DEVICES IS25LP080D
 #define EXTERNAL_FLASH_USE_QSPI
 
+#define PIN_GPS_RX PIN_SERIAL1_TX
+#define PIN_GPS_TX PIN_SERIAL1_RX
+
 #define PIN_GPS_1PPS      17  //GPS PPS pin
 #define GPS_BAUD_RATE   9600
 #define GPS_ADDRESS   0x42  //i2c address for GPS