Added .beginAutoBaudDetect()

Author: mikalhart

USERGUIDE.md

@@ -24,6 +24,9 @@ This library provides an interface for controlling and configuring an LG290P GNS
 - **`bool begin(HardwareSerial &serialPort, Print *parserDebug = nullptr, Print *parserError = &Serial);`**  
   Initialize communication with the GNSS module using a serial port. Optional debugging and error printing can be specified.
 
+- **`bool beginAutoBaudDetect(HardwareSerial &serialPort, int rxPin, int txPin, Print *parserDebug = nullptr, Print *parserError = &Serial);`**  
+  Auto-detect which baud rate the port is connected at. Repeatedly calls 'begin()' above, trying all the various baud rates that the LG290P supports, starting with the default, 480600. Optional debugging and error printing can be specified.
+
 - **`bool isConnected();`**  
   Check if the GNSS module is connected.
 

keywords.txt

@@ -13,6 +13,7 @@ LG290P	KEYWORD1
 #######################################
 
 begin	KEYWORD2
+beginAutoBaudDetect	KEYWORD2
 isConnected	KEYWORD2
 isBlocking	KEYWORD2
 update	KEYWORD2

src/SparkFun_LG290P_GNSS.cpp

@@ -128,17 +128,35 @@ bool LG290P::begin(HardwareSerial &serialPort, Print *parserDebug, Print *parser
     ok = ok && getMode(devState.mode);
     ok = ok && scanForMsgsEnabled();
 
-    debugPrintf("Starting with %s mode, GGA %d RMC %d EPE %d PVT %d PL %d SVIN %d GSV %d", 
-        devState.mode == BASEMODE ? "BASE" : "ROVER", devState.ggaRate, devState.rmcRate, devState.epeRate, 
-        devState.pvtRate, devState.plRate, devState.svinstatusRate, devState.gsvRate);
-    if (!ok)
+    if (ok)
+    {
+        debugPrintf("Starting with %s mode, GGA %d RMC %d EPE %d PVT %d PL %d SVIN %d GSV %d", 
+            devState.mode == BASEMODE ? "BASE" : "ROVER", devState.ggaRate, devState.rmcRate, devState.epeRate, 
+            devState.pvtRate, devState.plRate, devState.svinstatusRate, devState.gsvRate);
+    }
+    else
     {
+        debugPrintf("begin() failed.");
         sempStopParser(&_sempParse);
     }
 
     return ok;
 }
 
+bool LG290P::beginAutoBaudDetect(HardwareSerial &serialPort, int rxPin, int txPin, Print *parserDebug /* = nullptr */, Print *parserError /* = &Serial */)
+{
+    serialPort.setRxBufferSize(4096);
+
+    for (int baud: {460800, 921600, 230400, 115200, 9600})
+    {
+        debugPrintf("Trying baud rate %d...", baud);
+        serialPort.begin(baud, SERIAL_8N1, rxPin, txPin);
+        if (begin(serialPort, parserDebug, parserError))
+            return true;
+    }
+    return false;
+}
+
 // Query the device with 'UNIQID', expect OK response
 // Device may be booting and outputting other messages (ie, PQTMVER)
 // Try a few times

src/SparkFun_LG290P_GNSS.h

@@ -72,6 +72,17 @@ class LG290P
    */
   bool begin(HardwareSerial &serialPort, Print *parserDebug = nullptr, Print *parserError = &Serial);
 
+  /** 
+   * @brief Starts the LG290P engine. Does not require open serial port. Tests various likely baud rates
+   * @param serialPort a port that is connected to the LG290P module
+   * @param rxPin the pin that receives data from the LG290P
+   * @param txPin the pin that sends data to the LG290P
+   * @param parserDebug if provided, show debugging for the parser
+   * @param parserError if provided, show error messages for the parser
+   * @return true if the initialization succeeded
+   */
+  bool beginAutoBaudDetect(HardwareSerial &serialPort, int rxPin, int txPin, Print *parserDebug = nullptr, Print *parserError = &Serial);
+
   /** 
    * @brief Poll the device with the PQTMUNIQID command to see if it is responding
    * @return true if the device responds within 10 seconds