Provide CAN library for enabling useage of CAN for ArduinoCore-mbed e…

…nabled boards.

Caveat: which also make CAN available on their GPIOs.

libraries/Arduino_CAN/examples/CANRead/CANRead.ino

@@ -0,0 +1,30 @@
+/**************************************************************************************
+ * INCLUDE
+ **************************************************************************************/
+
+#include <Arduino_CAN.h>
+
+/**************************************************************************************
+ * SETUP/LOOP
+ **************************************************************************************/
+
+void setup()
+{
+  Serial.begin(115200);
+  while (!Serial) { }
+
+  if (!CAN.begin(CanBitRate::BR_250k))
+  {
+    Serial.println("CAN.begin(...) failed.");
+    for (;;) {}
+  }
+}
+
+void loop()
+{
+  if (CAN.available())
+  {
+    CanMsg const msg = CAN.read();
+    Serial.println(msg);
+  }
+}

libraries/Arduino_CAN/examples/CANWrite/CANWrite.ino

@@ -0,0 +1,55 @@
+/**************************************************************************************
+ * INCLUDE
+ **************************************************************************************/
+
+#include <Arduino_CAN.h>
+
+/**************************************************************************************
+ * CONSTANTS
+ **************************************************************************************/
+
+static uint32_t const CAN_ID = 0x20;
+
+/**************************************************************************************
+ * SETUP/LOOP
+ **************************************************************************************/
+
+void setup()
+{
+  Serial.begin(115200);
+  while (!Serial) { }
+
+  if (!CAN.begin(CanBitRate::BR_250k))
+  {
+    Serial.println("CAN.begin(...) failed.");
+    for (;;) {}
+  }
+}
+
+static uint32_t msg_cnt = 0;
+
+void loop()
+{
+  /* Assemble a CAN message with the format of
+   * 0xCA 0xFE 0x00 0x00 [4 byte message counter]
+   */
+  uint8_t const msg_data[] = {0xCA,0xFE,0,0,0,0,0,0};
+  memcpy((void *)(msg_data + 4), &msg_cnt, sizeof(msg_cnt));
+  CanMsg msg(CAN_ID, sizeof(msg_data), msg_data);
+
+  /* Transmit the CAN message, capture and display an
+   * error core in case of failure.
+   */
+  if (int const rc = CAN.write(msg); rc < 0)
+  {
+    Serial.print  ("CAN.write(...) failed with error code ");
+    Serial.println(rc);
+    for (;;) { }
+  }
+
+  /* Increase the message counter. */
+  msg_cnt++;
+
+  /* Only send one message per second. */
+  delay(1000);
+}

libraries/Arduino_CAN/keywords.txt

@@ -0,0 +1,32 @@
+#######################################
+# Syntax Coloring Map for CAN
+#######################################
+
+#######################################
+# Class (KEYWORD1)
+#######################################
+
+CAN	KEYWORD1
+CAN1	KEYWORD1
+CanMsg	KEYWORD1
+CanBitRate	KEYWORD1
+
+#######################################
+# Methods and Functions (KEYWORD2)
+#######################################
+
+begin	KEYWORD2
+end	KEYWORD2
+write	KEYWORD2
+available	KEYWORD2
+read	KEYWORD2
+
+#######################################
+# Constants (LITERAL1)
+#######################################
+
+BR_100k	LITERAL1
+BR_125k	LITERAL1
+BR_250k	LITERAL1
+BR_500k	LITERAL1
+BR_1000k	LITERAL1

libraries/Arduino_CAN/library.properties

@@ -0,0 +1,10 @@
+name=Arduino_CAN
+version=1.0.0
+author=Arduino
+maintainer=Arduino <[email protected]>
+sentence=CAN communication library for ArduinoCore-mbed enabled boards.
+paragraph=This library provides CAN for ArduinoCore-mbed enabled boards which expose CAN on their connectors.
+category=Other
+url=
+architectures=mbed,mbed_portenta
+include=Arduino_CAN.h

libraries/Arduino_CAN/src/Arduino_CAN.cpp

@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2022 by Alexander Entinger <[email protected]>
+ * Arduino_CAN library for Arduino.
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of either the GNU General Public License version 2
+ * or the GNU Lesser General Public License version 2.1, both as
+ * published by the Free Software Foundation.
+ */
+
+/**************************************************************************************
+ * INCLUDE
+ **************************************************************************************/
+
+#include "Arduino_CAN.h"
+
+/**************************************************************************************
+ * NAMESPACE
+ **************************************************************************************/
+
+namespace arduino
+{
+
+/**************************************************************************************
+ * CTOR/DTOR
+ **************************************************************************************/
+
+Arduino_CAN::Arduino_CAN(PinName const can_tx_pin, PinName const can_rx_pin)
+: _can(can_rx_pin, can_tx_pin)
+{
+
+}
+
+/**************************************************************************************
+ * PUBLIC MEMBER FUNCTIONS
+ **************************************************************************************/
+
+bool Arduino_CAN::begin(CanBitRate const can_bitrate)
+{
+  int const rc = _can.frequency(static_cast<int>(can_bitrate));
+  return (rc == 1);
+}
+
+void Arduino_CAN::end()
+{
+  /* Nothing to do. */
+}
+
+int Arduino_CAN::write(CanMsg const & msg)
+{
+  mbed::CANMessage const can_msg(
+    msg.id,
+    msg.data,
+    msg.data_length,
+    CANData,
+    CANStandard);
+
+  return _can.write(can_msg);
+}
+
+size_t Arduino_CAN::available()
+{
+  mbed::CANMessage can_msg;
+  bool const msg_read = _can.read(can_msg) > 0;
+
+  CanMsg const msg(
+    can_msg.id,
+    can_msg.len,
+    can_msg.data);
+
+  _rx_msg_buf.enqueue(msg);
+  return _rx_msg_buf.available();
+}
+
+CanMsg Arduino_CAN::read()
+{
+  return _rx_msg_buf.dequeue();
+}
+
+/**************************************************************************************
+ * NAMESPACE
+ **************************************************************************************/
+
+} /* arduino */
+
+/**************************************************************************************
+ * OBJECT INSTANTIATION
+ **************************************************************************************/
+
+#if CAN_HOWMANY > 0
+arduino::Arduino_CAN CAN(PIN_CAN0_TX, PIN_CAN0_RX);
+#endif
+
+#if CAN_HOWMANY > 1
+arduino::Arduino_CAN CAN1(PIN_CAN1_TX, PIN_CAN1_RX);
+#endif

libraries/Arduino_CAN/src/Arduino_CAN.h

@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2022 by Alexander Entinger <[email protected]>
+ * CAN library for Arduino.
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of either the GNU General Public License version 2
+ * or the GNU Lesser General Public License version 2.1, both as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef ARDUINO_CORE_MBED_CAN_H_
+#define ARDUINO_CORE_MBED_CAN_H_
+
+/**************************************************************************************
+ * INCLUDE
+ **************************************************************************************/
+
+#include <Arduino.h>
+#include <mbed.h>
+
+#include "api/HardwareCAN.h"
+
+/**************************************************************************************
+ * COMPILE TIME CHECKS
+ **************************************************************************************/
+
+#if !(defined(ARDUINO_PORTENTA_H7_M7) || defined(ARDUINO_PORTENTA_H7_M4))
+# error "CAN only available on Arduino Portenta H7 (of all ArduinoCore-mbed enabled boards)."
+#endif
+
+/**************************************************************************************
+ * TYPEDEF
+ **************************************************************************************/
+
+typedef arduino::CanMsg CanMsg;
+
+/**************************************************************************************
+ * NAMESPACE
+ **************************************************************************************/
+
+namespace arduino
+{
+
+/**************************************************************************************
+ * CLASS DECLARATION
+ **************************************************************************************/
+
+class Arduino_CAN final : public HardwareCAN
+{
+public:
+  Arduino_CAN(PinName const can_tx_pin, PinName const can_rx_pin);
+  virtual ~Arduino_CAN() { }
+
+
+  bool begin(CanBitRate const can_bitrate) override;
+  void end() override;
+
+
+  int write(CanMsg const & msg) override;
+  size_t available() override;
+  CanMsg read() override;
+
+private:
+  mbed::CAN _can;
+  CanMsgRingbuffer _rx_msg_buf;
+};
+
+/**************************************************************************************
+ * NAMESPACE
+ **************************************************************************************/
+
+} /* arduino */
+
+/**************************************************************************************
+ * EXTERN DECLARATION
+ **************************************************************************************/
+
+#if CAN_HOWMANY > 0
+extern arduino::Arduino_CAN CAN;
+#endif
+
+#if CAN_HOWMANY > 1
+extern arduino::Arduino_CAN CAN1;
+#endif
+
+#endif /* ARDUINO_CORE_MBED_CAN_H_ */

variants/PORTENTA_H7_M4/pins_arduino.h

@@ -8,4 +8,4 @@
 #include "../GIGA/pins_arduino.h"
 #endif
 
-#undef SERIAL_CDC
+#undef SERIAL_CDC

variants/PORTENTA_H7_M4/variant.cpp

@@ -12,4 +12,4 @@
 
 #undef initVariant
 
-void initVariant() {}
+void initVariant() {}

variants/PORTENTA_H7_M7/pins_arduino.h

@@ -164,4 +164,9 @@ void _ontouch1200bps_();
 
 #define USB_MAX_POWER	(500)
 
+#define CAN_HOWMANY       1
+
+#define PIN_CAN0_TX       (PH_13)
+#define PIN_CAN0_RX       (PB_8)
+
 #endif //__PINS_ARDUINO__

variants/PORTENTA_H7_M7/variant.cpp

@@ -78,7 +78,7 @@ PinDescription g_APinDescription[] = {
   { PB_5,         NULL, NULL, NULL },
   { PB_6,         NULL, NULL, NULL },
   { PB_7,         NULL, NULL, NULL },
-  { PB_8,         NULL, NULL, NULL },
+  { PB_8,         NULL, NULL, NULL },    // CAN1 RX
   { PB_9,         NULL, NULL, NULL },
   { PB_10,        NULL, NULL, NULL },
   { PB_11,        NULL, NULL, NULL },
@@ -179,7 +179,7 @@ PinDescription g_APinDescription[] = {
   { PH_10,        NULL, NULL, NULL },
   { PH_11,        NULL, NULL, NULL },
   { PH_12,        NULL, NULL, NULL },
-  { PH_13,        NULL, NULL, NULL },
+  { PH_13,        NULL, NULL, NULL },    // CAN1 TX
   { PH_14,        NULL, NULL, NULL },
   { PH_15,        NULL, NULL, NULL },
   { PI_0,         NULL, NULL, NULL },