Add UART hardware flow control (sandeepmistry#48)

* Add UART hardware flow control option

Author: d00616

cores/nRF5/Uart.cpp

@@ -27,6 +27,18 @@ Uart::Uart(NRF_UART_Type *_nrfUart, IRQn_Type _IRQn, uint8_t _pinRX, uint8_t _pi
   IRQn = _IRQn;
   uc_pinRX = g_ADigitalPinMap[_pinRX];
   uc_pinTX = g_ADigitalPinMap[_pinTX];
+  uc_hwFlow = 0;
+}
+
+Uart::Uart(NRF_UART_Type *_nrfUart, IRQn_Type _IRQn, uint8_t _pinRX, uint8_t _pinTX, uint8_t _pinCTS, uint8_t _pinRTS)
+{
+  nrfUart = _nrfUart;
+  IRQn = _IRQn;
+  uc_pinRX = g_ADigitalPinMap[_pinRX];
+  uc_pinTX = g_ADigitalPinMap[_pinTX];
+  uc_pinCTS = g_ADigitalPinMap[_pinCTS];
+  uc_pinRTS = g_ADigitalPinMap[_pinRTS];
+  uc_hwFlow = 1;
 }
 
 void Uart::begin(unsigned long baudrate)
@@ -39,7 +51,14 @@ void Uart::begin(unsigned long baudrate, uint16_t /*config*/)
   nrfUart->PSELTXD = uc_pinTX;
   nrfUart->PSELRXD = uc_pinRX;
 
-  nrfUart->CONFIG = (UART_CONFIG_PARITY_Excluded << UART_CONFIG_PARITY_Pos) | UART_CONFIG_HWFC_Disabled;
+  if (uc_hwFlow == 1) {
+    nrfUart->PSELCTS = uc_pinCTS;
+    nrfUart->PSELRTS = uc_pinRTS;
+    nrfUart->CONFIG = (UART_CONFIG_PARITY_Excluded << UART_CONFIG_PARITY_Pos) | UART_CONFIG_HWFC_Enabled;
+  } else {
+    nrfUart->CONFIG = (UART_CONFIG_PARITY_Excluded << UART_CONFIG_PARITY_Pos) | UART_CONFIG_HWFC_Disabled;
+  }
+
 
   uint32_t nrfBaudRate;
 
@@ -144,6 +163,9 @@ void Uart::end()
   nrfUart->PSELTXD = 0xFFFFFFFF;
   nrfUart->PSELRXD = 0xFFFFFFFF;
 
+  nrfUart->PSELRTS = 0xFFFFFFFF;
+  nrfUart->PSELCTS = 0xFFFFFFFF;
+
   rxBuffer.clear();
 }
 
@@ -188,8 +210,18 @@ size_t Uart::write(const uint8_t data)
 }
 
 #if defined(NRF52)
-Uart Serial( NRF_UART0, UARTE0_UART0_IRQn, PIN_SERIAL_RX, PIN_SERIAL_TX );
+  #define NRF_UART0_IRQn UARTE0_UART0_IRQn
+#elif defined(NRF51)
+  #define NRF_UART0_IRQn UART0_IRQn
+#endif
 
+#if defined(PIN_SERIAL_CTS) && defined(PIN_SERIAL_RTS)
+  Uart Serial( NRF_UART0, NRF_UART0_IRQn, PIN_SERIAL_RX, PIN_SERIAL_TX, PIN_SERIAL_CTS, PIN_SERIAL_RTS );
+#else
+  Uart Serial( NRF_UART0, NRF_UART0_IRQn, PIN_SERIAL_RX, PIN_SERIAL_TX );
+#endif
+
+#if defined(NRF52)
 extern "C"
 {
   void UARTE0_UART0_IRQHandler()
@@ -198,8 +230,6 @@ extern "C"
   }
 }
 #elif defined(NRF51)
-Uart Serial( NRF_UART0, UART0_IRQn, PIN_SERIAL_RX, PIN_SERIAL_TX );
-
 extern "C"
 {
   void UART0_IRQHandler()

cores/nRF5/Uart.h

@@ -30,6 +30,7 @@ class Uart : public HardwareSerial
 {
   public:
     Uart(NRF_UART_Type *_nrfUart, IRQn_Type _IRQn, uint8_t _pinRX, uint8_t _pinTX);
+    Uart(NRF_UART_Type *_nrfUart, IRQn_Type _IRQn, uint8_t _pinRX, uint8_t _pinTX, uint8_t _pinCTS, uint8_t _pinRTS );
     void begin(unsigned long baudRate);
     void begin(unsigned long baudrate, uint16_t config);
     void end();
@@ -52,6 +53,9 @@ class Uart : public HardwareSerial
 
     uint8_t uc_pinRX;
     uint8_t uc_pinTX;
+    uint8_t uc_pinCTS;
+    uint8_t uc_pinRTS;
+    uint8_t uc_hwFlow;
 };
 
 #ifdef __cplusplus