Allow USB Serial to be disabled, redirect to UART Serial

This will set the default Serial output to UART if USB CDC is disabled by setting USB_CDC_DEFAULT_SERIAL to 0.

If the board has serial1 pins defined they will be redefined to Serial and Serial1 will be aliased to Serial

Author: h2zero

cores/nRF5/Arduino.h

@@ -54,16 +54,11 @@ void loop( void ) ;
   #include "WMath.h"
   #include "HardwareSerial.h"
   #include "pulse.h"
-#endif
-#include "delay.h"
-#include "binary.h"
-#ifdef __cplusplus
   #include "Uart.h"
 #endif
 
-#ifdef USE_TINYUSB
-  #include "Adafruit_USBD_CDC.h"
-#endif
+#include "delay.h"
+#include "binary.h"
 
 // Include board variant
 #include "variant.h"

cores/nRF5/TinyUSB/Adafruit_TinyUSB_ArduinoCore/Adafruit_USBD_CDC.h

@@ -95,14 +95,6 @@ class Adafruit_USBD_CDC : public Stream, public Adafruit_USBD_Interface {
 
 extern Adafruit_USBD_CDC SerialTinyUSB;
 
-// Built-in support "Serial" is assigned to TinyUSB CDC
-// CH32 defines Serial as alias in WSerial.h
-#if defined(USE_TINYUSB) && !defined(ARDUINO_ARCH_CH32)
-#define SerialTinyUSB Serial
-#endif
-
-extern Adafruit_USBD_CDC SerialTinyUSB;
-
 #endif // else of ESP32
 #endif // __cplusplus
 

cores/nRF5/Uart.cpp

@@ -17,7 +17,6 @@
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
-#include "Uart.h"
 #include "Arduino.h"
 #include "wiring_private.h"
 
@@ -256,10 +255,10 @@ Uart::operator bool() {
   #define NRF_UART0_IRQn UART0_IRQn
 #endif
 
-#if !defined(USB_CDC_DEFAULT_SERIAL)
+#if !USB_CDC_DEFAULT_SERIAL
 #  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
+#  elif defined(PIN_SERIAL_RX) && defined(PIN_SERIAL_TX) // may not be defined if USB CDC default is disabled
       Uart Serial( NRF_UART0, NRF_UART0_IRQn, PIN_SERIAL_RX, PIN_SERIAL_TX );
 #  endif
 #endif

cores/nRF5/Uart.h

@@ -27,6 +27,12 @@
 #include <cstddef>
 
 #include "variant.h"
+#ifndef USB_CDC_DEFAULT_SERIAL
+  #define USB_CDC_DEFAULT_SERIAL 0
+#endif
+#ifdef USE_TINYUSB
+  #include "Adafruit_USBD_CDC.h"
+#endif
 
 class Uart : public HardwareSerial
 {
@@ -62,7 +68,6 @@ class Uart : public HardwareSerial
     uint8_t uc_hwFlow;
 };
 
-
 // These serial port names are intended to allow libraries and architecture-neutral
 // sketches to automatically default to the correct port name for a particular type
 // of use.  For example, a GPS module would normally connect to SERIAL_PORT_HARDWARE_OPEN,
@@ -78,19 +83,28 @@ class Uart : public HardwareSerial
 //
 // SERIAL_PORT_HARDWARE_OPEN  Hardware serial ports which are open for use.  Their RX & TX
 //                            pins are NOT connected to anything by default.
-#if defined(USB_CDC_DEFAULT_SERIAL)
+#if defined(USE_TINYUSB) && USB_CDC_DEFAULT_SERIAL
+// Built-in support "Serial" is assigned to TinyUSB CDC
+// Don't define Serial if user wants to use Serial for other purpose, e.g. UART
+  #define Serial SerialTinyUSB
   #define SERIAL_PORT_MONITOR         Serial
   #define SERIAL_PORT_USBVIRTUAL      Serial
 
   #define SERIAL_PORT_HARDWARE        Serial1
   #define SERIAL_PORT_HARDWARE_OPEN   Serial1
 #else
+  // If USB CDC default is disabled, make Serial to be the default UART port
+  #if defined(PIN_SERIAL1_RX) && defined(PIN_SERIAL1_TX) && \
+      !defined(PIN_SERIAL_RX) && !defined(PIN_SERIAL_TX)
+    #define Serial Serial1
+  #endif
+
   #define SERIAL_PORT_MONITOR         Serial
   #define SERIAL_PORT_HARDWARE        Serial
 #endif
 
-extern Uart SERIAL_PORT_HARDWARE;
-
 #if defined(PIN_SERIAL1_RX) && defined(PIN_SERIAL1_TX)
-extern Uart Serial1;
+  extern Uart Serial1;
 #endif
+
+extern Uart SERIAL_PORT_HARDWARE;

cores/nRF5/libc/printf/putchar.cpp

@@ -68,7 +68,7 @@ extern "C"
             Serial.write((const uint8_t *)pbuf->buffer, pbuf->index);
             pbuf->index = 0;
         }
-#ifdef USB_CDC_DEFAULT_SERIAL
+#if USB_CDC_DEFAULT_SERIAL
         Serial.flush();
 #endif
     }
@@ -85,7 +85,7 @@ extern "C"
                 Serial.write('\r');
             }
             Serial.write(c);
-#ifdef USB_CDC_DEFAULT_SERIAL
+#if USB_CDC_DEFAULT_SERIAL
             Serial.flush();
 #endif
             return;

cores/nRF5/utils/debug_utils.cpp

@@ -177,7 +177,7 @@ static size_t capture_backtrace(uint32_t* backtrace_buffer, size_t buffer_size,
  */
 static void store_fault_to_ram(exception_frame* ef, uint32_t exc_return_val)
 {
-#ifdef USB_CDC_DEFAULT_SERIAL
+#if USB_CDC_DEFAULT_SERIAL
     volatile fault_data_t* fault = FAULT_DATA_ADDR;
     fault->magic = FAULT_DATA_MAGIC;
     fault->pc = ef->pc;
@@ -240,7 +240,7 @@ static void store_fault_to_ram(exception_frame* ef, uint32_t exc_return_val)
 static void print_exception_data(exception_frame* ef)
 {
 // If USB is used for Serial we must avoid using it in HardFault handler
-#ifndef USB_CDC_DEFAULT_SERIAL
+#if !USB_CDC_DEFAULT_SERIAL
     if (Serial)
     {
         Serial.println("\n======== HARD FAULT DETECTED ========");
@@ -320,7 +320,7 @@ static void print_exception_data(exception_frame* ef)
  */
 void check_and_report_fault()
 {
-#ifdef USB_CDC_DEFAULT_SERIAL
+#if USB_CDC_DEFAULT_SERIAL
     volatile fault_data_t* fault = FAULT_DATA_ADDR;
 
     if (fault->magic == FAULT_DATA_MAGIC)

variants/Seeed_XIAO_nRF52840_Sense/variant.h

@@ -87,7 +87,9 @@ static const uint8_t A5  = PIN_A5;
 // Serial interfaces
 #define PIN_SERIAL1_RX          (7)
 #define PIN_SERIAL1_TX          (6)
-#define USB_CDC_DEFAULT_SERIAL  1
+#ifndef USB_CDC_DEFAULT_SERIAL
+#define USB_CDC_DEFAULT_SERIAL  (1)
+#endif
 
 // SPI Interfaces
 #define SPI_INTERFACES_COUNT    (2)

variants/circuitplayground_nrf52840/variant.h

@@ -92,9 +92,11 @@ static const uint8_t A9  = PIN_A9 ;
 /*
  * Serial interfaces
  */
-#define PIN_SERIAL1_RX       (0)
-#define PIN_SERIAL1_TX       (1)
-#define USB_CDC_DEFAULT_SERIAL 1
+#define PIN_SERIAL1_RX         (0)
+#define PIN_SERIAL1_TX         (1)
+#ifndef USB_CDC_DEFAULT_SERIAL
+#define USB_CDC_DEFAULT_SERIAL (1)
+#endif
 
 /*
  * SPI Interfaces

variants/clue_nrf52840/variant.h

@@ -89,9 +89,11 @@ static const uint8_t A7  = PIN_A7 ;
 /*
  * Serial interfaces
  */
-#define PIN_SERIAL1_RX       (0)
-#define PIN_SERIAL1_TX       (1)
-#define USB_CDC_DEFAULT_SERIAL 1
+#define PIN_SERIAL1_RX         (0)
+#define PIN_SERIAL1_TX         (1)
+#ifndef USB_CDC_DEFAULT_SERIAL
+#define USB_CDC_DEFAULT_SERIAL (1)
+#endif
 
 /*
  * SPI Interfaces

variants/feather_nrf52840_express/variant.h

@@ -91,9 +91,11 @@ static const uint8_t AREF = PIN_AREF;
 /*
  * Serial interfaces
  */
-#define PIN_SERIAL1_RX       (1)
-#define PIN_SERIAL1_TX       (0)
-#define USB_CDC_DEFAULT_SERIAL 1
+#define PIN_SERIAL1_RX         (1)
+#define PIN_SERIAL1_TX         (0)
+#ifndef USB_CDC_DEFAULT_SERIAL
+#define USB_CDC_DEFAULT_SERIAL (1)
+#endif
 
 /*
  * SPI Interfaces