Merge branch 'develop' into fix-radio-init

Support softsleep by defining PIN_GPS_STANDBY on CDTop CD-PA1010D.

This differs from existing MTK GPS e.g. L76K, where pulling PIN_GPS_STANDBY (WAKE-UP pin) low is not sufficient to put the GPS module in standby.

An additional `$PMTK225,4*2F` must be sent to enter "Backup Mode", which is exited by bringing PIN_GPS_STANDBY (WAKE-UP pin) high.

Refer to datasheet[0] §1.9.3 "Backup Mode".

0: https://cdn-learn.adafruit.com/assets/assets/000/084/295/original/CD_PA1010D_Datasheet_v.03.pdf

Signed-off-by: Andrew Yong <me@ndoo.sg>

src/gps/GPS.cpp

@@ -905,6 +905,12 @@ void GPS::writePinStandby(bool standby)
     // Write and log
     pinMode(PIN_GPS_STANDBY, OUTPUT);
     digitalWrite(PIN_GPS_STANDBY, val);
+
+    // Enter backup mode on PA1010D; TODO: may be applicable to other MTK GPS too
+    if (IS_ONE_OF(gnssModel, GNSS_MODEL_MTK_PA1010D)) {
+        _serial_gps->write("$PMTK225,4*2F\r\n");
+    }
+
 #ifdef GPS_DEBUG
     LOG_DEBUG("Pin STANDBY %s", val == HIGH ? "HI" : "LOW");
 #endif

src/mesh/LR11x0Interface.cpp

@@ -91,10 +91,21 @@ template <typename T> bool LR11x0Interface<T>::init()
     LOG_DEBUG("Set RF1 switch to %s", getFreq() < 1e9 ? "SubGHz" : "2.4GHz");
 #endif
 
+    // Allow extra time for TCXO to stabilize after power-on
+    delay(10);
+
     int res = lora.begin(getFreq(), bw, sf, cr, syncWord, power, preambleLength, tcxoVoltage);
+
+    // Retry if we get SPI command failed - some units need extra TCXO stabilization time
+    if (res == RADIOLIB_ERR_SPI_CMD_FAILED) {
+        LOG_WARN("LR11x0 init failed with %d (SPI_CMD_FAILED), retrying after delay...", res);
+        delay(100);
+        res = lora.begin(getFreq(), bw, sf, cr, syncWord, power, preambleLength, tcxoVoltage);
+    }
+
     // \todo Display actual typename of the adapter, not just `LR11x0`
     LOG_INFO("LR11x0 init result %d", res);
-    if (res == RADIOLIB_ERR_CHIP_NOT_FOUND)
+    if (res == RADIOLIB_ERR_CHIP_NOT_FOUND || res == RADIOLIB_ERR_SPI_CMD_FAILED)
         return false;
 
     LR11x0VersionInfo_t version;

src/mesh/RF95Interface.cpp

@@ -177,6 +177,9 @@ bool RF95Interface::init()
 
     int res = lora->begin(getFreq(), bw, sf, cr, syncWord, power, preambleLength);
     LOG_INFO("RF95 init result %d", res);
+    if (res == RADIOLIB_ERR_CHIP_NOT_FOUND || res == RADIOLIB_ERR_SPI_CMD_FAILED)
+        return false;
+
     LOG_INFO("Frequency set to %f", getFreq());
     LOG_INFO("Bandwidth set to %f", bw);
     LOG_INFO("Power output set to %d", power);

src/mesh/SX128xInterface.cpp

@@ -69,6 +69,8 @@ template <typename T> bool SX128xInterface<T>::init()
     int res = lora.begin(getFreq(), bw, sf, cr, syncWord, power, preambleLength);
     // \todo Display actual typename of the adapter, not just `SX128x`
     LOG_INFO("SX128x init result %d", res);
+    if (res == RADIOLIB_ERR_CHIP_NOT_FOUND || res == RADIOLIB_ERR_SPI_CMD_FAILED)
+        return false;
 
     if ((config.lora.region != meshtastic_Config_LoRaConfig_RegionCode_LORA_24) && (res == RADIOLIB_ERR_INVALID_FREQUENCY)) {
         LOG_WARN("Radio only supports 2.4GHz LoRa. Adjusting Region and rebooting");