LpcUart: [#22] This could have worked.

* It appears that LPC11u68 has ony USART0 redirected to USB as debug UART.
* The code here was written only for USART1-4.

source/shoh/src/main.cpp

@@ -6,12 +6,17 @@
 #include "ThreadCommon.h"
 #include "Master.h"
 #include "Rotary.h"
-
+#include "retarget_uart.h"
 
 int main(void)
 {
   SystemCoreClockUpdate();
   Board_Init();
+
+  retarget_init();
+
+  printf("Hello there!\r\n");
+
   ThreadCommon::ThreadManager* manager = new ThreadCommon::ThreadManager;
   ThreadCommon::QueueManager* qmanager = new ThreadCommon::QueueManager;
   //Creating queues

source/shoh/src/peripherals/LpcUart.cpp

@@ -13,6 +13,10 @@
  * We don't have movable pins -> not needed.
  *
  * Muxing is like this:
+ * Chip_IOCON_PinMuxSet(LPC_IOCON, 0, 14, (IOCON_FUNC4 | IOCON_MODE_INACT | IOCON_DIGMODE_EN));
+ * Chip_IOCON_PinMuxSet(LPC_IOCON, 0, 13, (IOCON_FUNC4 | IOCON_MODE_INACT | IOCON_DIGMODE_EN));
+ * 
+ * USART0 (the only debug uart):
  * Chip_IOCON_PinMuxSet(LPC_IOCON, 0, 18, (IOCON_FUNC1 | IOCON_MODE_INACT | IOCON_DIGMODE_EN));
  * Chip_IOCON_PinMuxSet(LPC_IOCON, 0, 19, (IOCON_FUNC1 | IOCON_MODE_INACT | IOCON_DIGMODE_EN));
  */
@@ -90,7 +94,7 @@ LpcUart::LpcUart(const LpcUartConfig &cfg) {
 		 * UARTs.
 		 * */
 		/* Use main clock rate as base for UART baud rate divider */
-		Chip_Clock_SetUSARTNBaseClockRate(Chip_Clock_GetMainClockRate(), false);
+		Chip_Clock_SetUSARTNBaseClockRate(Chip_Clock_GetMainClockRate(), false); //(115200 * 256), false);
 	}
 
 	uart = nullptr; // set default value before checking which UART to configure
@@ -123,19 +127,19 @@ LpcUart::LpcUart(const LpcUartConfig &cfg) {
 
 
 	if(cfg.tx.port >= 0) {
-		Chip_IOCON_PinMuxSet(LPC_IOCON, cfg.tx.port, cfg.tx.pin, (IOCON_FUNC1 | IOCON_MODE_INACT | IOCON_DIGMODE_EN));
+		Chip_IOCON_PinMuxSet(LPC_IOCON, cfg.tx.port, cfg.tx.pin, (IOCON_FUNC4 | IOCON_MODE_INACT | IOCON_DIGMODE_EN));
 	}
 
 	if(cfg.rx.port >= 0) {
-		Chip_IOCON_PinMuxSet(LPC_IOCON, cfg.rx.port, cfg.rx.pin, (IOCON_FUNC1 | IOCON_MODE_INACT | IOCON_DIGMODE_EN));
+		Chip_IOCON_PinMuxSet(LPC_IOCON, cfg.rx.port, cfg.rx.pin, (IOCON_FUNC4 | IOCON_MODE_INACT | IOCON_DIGMODE_EN));
 	}
 
 	if(use_cts) {
-		Chip_IOCON_PinMuxSet(LPC_IOCON, cfg.cts.port, cfg.cts.pin, (IOCON_FUNC1 | IOCON_MODE_INACT | IOCON_DIGMODE_EN));
+		Chip_IOCON_PinMuxSet(LPC_IOCON, cfg.cts.port, cfg.cts.pin, (IOCON_FUNC4 | IOCON_MODE_INACT | IOCON_DIGMODE_EN));
 	}
 
 	if(use_rts) {
-		Chip_IOCON_PinMuxSet(LPC_IOCON, cfg.rts.port, cfg.rts.pin, (IOCON_FUNC1 | IOCON_MODE_INACT | IOCON_DIGMODE_EN));
+		Chip_IOCON_PinMuxSet(LPC_IOCON, cfg.rts.port, cfg.rts.pin, (IOCON_FUNC4 | IOCON_MODE_INACT | IOCON_DIGMODE_EN));
 	}
 
 	notify_rx = nullptr;

source/shoh/src/peripherals/retarget_uart.cpp

@@ -0,0 +1,91 @@
+/*
+ * retarget_uart.cpp
+ *
+ *  Created on: 28.9.2021
+ *      Author: keijo
+ */
+
+#include "LpcUart.h"
+
+static LpcUart *dbgu;
+
+void retarget_init()
+{
+	LpcPinMap none = {-1, -1}; // unused pin has negative values in it
+	//Sadly, it seems that only USART0 is redirected to USB.
+	//It means that those are pins PIO0_18 and PIO0_19
+	LpcPinMap txpin = { 0, 14 }; // transmit pin that goes to debugger's UART->USB converter
+	LpcPinMap rxpin = { 0, 13 }; // receive pin that goes to debugger's UART->USB converter
+	LpcUartConfig cfg = { LPC_USART1, 115200, UARTN_CFG_DATALEN_8 | UARTN_CFG_PARITY_NONE | UARTN_CFG_STOPLEN_1, false, txpin, rxpin, none, none };
+	dbgu = new LpcUart(cfg);
+}
+
+extern "C" {
+
+// ******************************************************************
+// Redlib C Library function : __sys_write
+// Newlib C library function : _write
+//
+// Function called by bottom level of printf routine within C library.
+// With the default semihosting stub, this would write the
+// character(s) to the debugger console window (which acts as
+// stdout). But this version writes the character(s) to UART
+// ******************************************************************
+#if defined (__REDLIB__)
+int __sys_write(int iFileHandle, char *pcBuffer, int iLength) {
+#elif defined (__NEWLIB__)
+int _write(int iFileHandle, char *pcBuffer, int iLength) {
+#endif
+	if(dbgu) {
+		int len = iLength;
+		while(len > 0) {
+			if(*pcBuffer == '\n') { // send a CR before every LF
+				while(dbgu->write('\r')==0);
+			}
+			while(dbgu->write(*pcBuffer)==0);
+			++pcBuffer;
+			--len;
+		}
+	}
+	// Function returns number of bytes written
+	return iLength;
+}
+
+#if defined (__REDLIB__)
+// ******************************************************************
+// Redlib C Library function : __sys_readc
+//
+// Called by bottom level of scanf routine within RedLib C library
+// to read a character. With the default semihosting stub, this
+// would read the character from the debugger console window (which
+// acts as stdin). But this version reads the character from UART
+// ******************************************************************
+
+int __sys_readc(void) {
+	char c;
+	if(dbgu && dbgu->read(c)) return c;
+	else return -1;
+
+}
+// #endif REDLIB __sys_readc()
+
+#elif defined (__NEWLIB__)
+// ******************************************************************
+// Function _read
+//
+// Called by bottom level of scanf routine within Newlib C library
+// to read multiple characters. With the default semihosting stub, this
+// would read  characters from the debugger console window (which
+// acts as stdin). But this version reads the characters from UART
+// ******************************************************************
+int _read(int iFileHandle, char *pcBuffer, int iLength) {
+
+	// TODO : Should potentially check that iFileHandle == 0 to confirm
+	// that read is from stdin
+	if(!dbgu) return 0;
+	return dbgu->read(pcBuffer, iLength);
+}
+
+#endif // NEWLIB _read()
+
+}

source/shoh/src/peripherals/retarget_uart.h

@@ -0,0 +1,14 @@
+/*
+ * retarget_uart.h
+ *
+ *  Created on: 28.9.2021
+ *      Author: keijo
+ */
+
+#ifndef RETARGET_UART_H_
+#define RETARGET_UART_H_
+
+void retarget_init();
+
+
+#endif /* RETARGET_UART_H_ */

source/shoh/src/threads/master/Master.cpp

@@ -21,15 +21,19 @@ void Master::taskFunction() {
 		{
 			case ThreadCommon::RotaryAction::Right:
 				Board_LED_Set(ThreadCommon::RotaryAction::Right, LedState);
+				printf("Right\r\n");
 				break;
 			case ThreadCommon::RotaryAction::Left:
 				Board_LED_Set(ThreadCommon::RotaryAction::Left, LedState);
+				printf("Left\r\n");
 				break;
 			case ThreadCommon::RotaryAction::Press:
 				Board_LED_Set(ThreadCommon::RotaryAction::Press, LedState);
+				printf("Press\r\n");
 				break;
 			case ThreadCommon::RotaryAction::Idle:
 				Board_LED_Set(ThreadCommon::RotaryAction::Right, LedState);
+				printf("Idle\r\n");
 				break;
 		}
 		LedState = !LedState;