Add simpler checkUblox locking

Author: PaulZC

src/u-blox_GNSS.cpp

@@ -1048,10 +1048,16 @@ const char *DevUBLOXGNSS::statusString(sfe_ublox_status_e stat)
 }
 
 // Check for the arrival of new I2C/Serial/SPI data
-
 // Called regularly to check for available bytes on the user' specified port
+
+void DevUBLOXGNSS::lockCheckUblox(void) { if (_enableCheckUbloxLock) _checkUbloxLock = true; }
+void DevUBLOXGNSS::unlockCheckUblox(void) { _checkUbloxLock = false; }
+
 bool DevUBLOXGNSS::checkUblox(uint8_t requestedClass, uint8_t requestedID)
 {
+  if (_checkUbloxLock)
+    return false;
+
   return checkUbloxInternal(&packetCfg, requestedClass, requestedID);
 }
 
@@ -4621,6 +4627,8 @@ void DevUBLOXGNSS::addToChecksum(uint8_t incoming)
 // Given a packet and payload, send everything including CRC bytes via I2C port
 sfe_ublox_status_e DevUBLOXGNSS::sendCommand(ubxPacket *outgoingUBX, uint16_t maxWait, bool expectACKonly)
 {
+  lockCheckUblox();
+
   if (!lock()) return SFE_UBLOX_STATUS_FAIL;
 
   sfe_ublox_status_e retVal = SFE_UBLOX_STATUS_SUCCESS;
@@ -4646,6 +4654,8 @@ sfe_ublox_status_e DevUBLOXGNSS::sendCommand(ubxPacket *outgoingUBX, uint16_t ma
         _debugSerial.println(F("Send I2C Command failed"));
       }
 #endif
+      unlock();
+      unlockCheckUblox();
       return retVal;
     }
   }
@@ -4688,6 +4698,9 @@ sfe_ublox_status_e DevUBLOXGNSS::sendCommand(ubxPacket *outgoingUBX, uint16_t ma
   {
     processSpiBuffer(&packetCfg, 0, 0); // Process any SPI data received during the sendSpiCommand - but only if not checking for a response
   }
+
+  unlockCheckUblox();
+
   return retVal;
 }
 

src/u-blox_GNSS.h

@@ -136,11 +136,19 @@ class DevUBLOXGNSS
   // Flag to indicate if we are connected to UART1 or UART2
   // Needed to select the correct config items when enabling a periodic message
   bool _UART2 = false; // Default to UART1
+  
   // the lock / unlock functions can be used if you have multiple tasks writing to the bus. 
   // the idea is that in a RTOS you override this class and the two functions in which you take and give a mutex.
   virtual bool lock(void) { return true; }
   virtual void unlock(void) { }
 
+  // A simpler lock to prevent checkUblox from being called while a sendCommand and waitForResponse is in progress
+  void lockCheckUblox(void)  __attribute__((weak));
+  void unlockCheckUblox(void)  __attribute__((weak));
+  volatile bool _checkUbloxLock = false;
+public:
+  volatile bool _enableCheckUbloxLock = false; // Change this to true to enable simple checkUblox locking
+
 public:
   void connectedToUART2(bool connected = true) { _UART2 = connected; }