Add STM32F1 HW support (#795)

drivers/RFM69/RFM69.cpp

@@ -90,6 +90,8 @@ bool RFM69::initialize(uint8_t freqBand, uint8_t nodeID, uint8_t networkID)
 
 	hwDigitalWrite(_slaveSelectPin, HIGH);
 	hwPinMode(_slaveSelectPin, OUTPUT);
+	hwPinMode(_interruptPin, INPUT);
+
 	SPI.begin();
 	unsigned long start = millis();
 	uint8_t timeout = 50;
@@ -500,8 +502,7 @@ void RFM69::select()
 	// set RFM69 SPI settings
 	SPI.setDataMode(SPI_MODE0);
 	SPI.setBitOrder(MSBFIRST);
-	SPI.setClockDivider(
-	    SPI_CLOCK_DIV4); // decided to slow down from DIV2 after SPI stalling in some instances, especially visible on mega1284p when RFM69 and FLASH chip both present
+	SPI.setClockDivider(MY_RF69_SPI_CLOCK_DIV);
 	hwDigitalWrite(_slaveSelectPin, LOW);
 }