SAMD Support Initial Patches

DCC.cpp

@@ -62,7 +62,11 @@ byte DCC::globalSpeedsteps=128;
 
 void DCC::begin(const FSH * motorShieldName) {
   shieldName=(FSH *)motorShieldName;
+#if defined(ARDUINO_ARCH_SAMD)
+  StringFormatter::send(SerialUSB,F("<iDCC-EX V-%S / %S / %S G-%S>\n"), F(VERSION), F(ARDUINO_TYPE), shieldName, F(GITHUB_SHA));
+#else
   StringFormatter::send(Serial,F("<iDCC-EX V-%S / %S / %S G-%S>\n"), F(VERSION), F(ARDUINO_TYPE), shieldName, F(GITHUB_SHA));
+#endif
 
 #ifndef DISABLE_EEPROM
   // Load stuff from EEprom

DCCEXParser.cpp

@@ -1,4 +1,5 @@
 /*
+ *  © 2022 Paul M Antoine
  *  © 2021 Neil McKechnie
  *  © 2021 Mike S
  *  © 2021 Herb Morton
@@ -881,7 +882,9 @@ bool DCCEXParser::parseD(Print *stream, int16_t params, int16_t p[])
           wdt_enable( WDTO_15MS); // set Arduino watchdog timer for 15ms 
           delay(50);            // wait for the prescaller time to expire
 #else
+#if defined(ARDUINO_ARCH_ESP)
 	  ESP.restart();
+#endif
 #endif
           break; // and <X> if we didnt restart 
         }

DCCTimer.h

@@ -1,4 +1,5 @@
 /*
+ *  © 2022 Paul M Antoine
  *  © 2021 Mike S
  *  © 2021 Harald Barth
  *  © 2021 Fred Decker
@@ -121,6 +122,9 @@ private:
 #elif defined(ARDUINO_ARCH_ESP32)
 #define ARDUINO_TYPE "ESP32"
 #undef HAS_AVR_WDT
+#elif defined(ARDUINO_ARCH_SAMD)
+#define ARDUINO_TYPE "SAMD21"
+#undef HAS_AVR_WDT
 #else
 #error CANNOT COMPILE - DCC++ EX ONLY WORKS WITH THE ARCHITECTURES LISTED IN DCCTimer.h
 #endif

DCCTimerSAMD.cpp

@@ -0,0 +1,170 @@
+/*
+ *  © 2022 Paul M Antoine
+ *  © 2021 Mike S
+ *  © 2021 Harald Barth
+ *  © 2021 Fred Decker
+ *  © 2021 Chris Harlow
+ *  © 2021 David Cutting
+ *  All rights reserved.
+ *  
+ *  This file is part of Asbelos DCC API
+ *
+ *  This is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  It is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with CommandStation.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+// ATTENTION: this file only compiles on a SAMD21 based board
+// Please refer to DCCTimer.h for general comments about how this class works
+// This is to avoid repetition and duplication.
+#ifdef ARDUINO_ARCH_SAMD
+
+#include "FSH.h" //PMA temp debug
+#include "DIAG.h" //PMA temp debug
+#include "DCCTimer.h"
+
+INTERRUPT_CALLBACK interruptHandler=0;
+
+void DCCTimer::begin(INTERRUPT_CALLBACK callback) {
+  interruptHandler=callback;
+  noInterrupts();
+
+  // Set up ADC to do faster reads... default for Arduino Zero platform configs is 436uS,
+  // and we need sub-100uS. This code sets it to a read speed of around 21uS, and for now
+  // enables 10-bit mode, although 12-bit is possible
+  ADC->CTRLA.bit.ENABLE = 0;              // disable ADC
+  while( ADC->STATUS.bit.SYNCBUSY == 1 ); // wait for synchronization
+
+  ADC->CTRLB.reg &= 0b1111100011111111;          // mask PRESCALER bits
+  ADC->CTRLB.reg |= ADC_CTRLB_PRESCALER_DIV64 |  // divide Clock by 64
+                    ADC_CTRLB_RESSEL_10BIT;      // Result on 10 bits default, 12 bits possible
+
+  ADC->AVGCTRL.reg = ADC_AVGCTRL_SAMPLENUM_1 |   // take 1 sample at a time
+                     ADC_AVGCTRL_ADJRES(0x00ul); // adjusting result by 0
+  ADC->SAMPCTRL.reg = 0x00;                      // sampling Time Length = 0
+
+  ADC->CTRLA.bit.ENABLE = 1;                     // enable ADC
+  while(ADC->STATUS.bit.SYNCBUSY == 1);          // wait for synchronization
+
+  // Timer setup - setup clock sources first
+  REG_GCLK_GENDIV =   GCLK_GENDIV_DIV(1) |            // Divide 48MHz by 1
+                      GCLK_GENDIV_ID(4);              // Apply to GCLK4
+  while (GCLK->STATUS.bit.SYNCBUSY);                  // Wait for synchronization
+                
+  REG_GCLK_GENCTRL =  GCLK_GENCTRL_GENEN |            // Enable GCLK
+                      GCLK_GENCTRL_SRC_DFLL48M |      // Set the 48MHz clock source
+                      GCLK_GENCTRL_ID(4);             // Select GCLK4
+  while (GCLK->STATUS.bit.SYNCBUSY);                  // Wait for synchronization
+            
+  REG_GCLK_CLKCTRL =  GCLK_CLKCTRL_CLKEN |            // Enable generic clock
+                      4 << GCLK_CLKCTRL_GEN_Pos |     // Apply to GCLK4
+                      GCLK_CLKCTRL_ID_TCC0_TCC1;      // Feed GCLK to TCC0/1
+  while (GCLK->STATUS.bit.SYNCBUSY);
+
+  // Assume we're using TCC0... as we're bit-bashing the DCC waveform output pins anyway
+  // for "normal accuracy" DCC waveform generation. For high accuracy we're going to need
+  // to a good deal more. The TCC waveform output pins are mux'd on the SAMD, and output
+  // pins for each TCC are only available on certain pins
+  TCC0->WAVE.reg = TCC_WAVE_WAVEGEN_NPWM;     // Select NPWM as waveform
+  while (TCC0->SYNCBUSY.bit.WAVE);            // Wait for sync
+
+  // Set the frequency
+  TCC0->CTRLA.reg |= TCC_CTRLA_PRESCALER(TCC_CTRLA_PRESCALER_DIV1_Val);
+  TCC0->PER.reg = CLOCK_CYCLES * 2;
+  while (TCC0->SYNCBUSY.bit.PER);
+
+  // Start the timer
+  TCC0->CTRLA.bit.ENABLE = 1;
+  while (TCC0->SYNCBUSY.bit.ENABLE);
+
+  // Set the interrupt condition, priority and enable it in the NVIC
+  TCC0->INTENSET.reg = TCC_INTENSET_OVF;      // Only interrupt on overflow
+  NVIC_SetPriority((IRQn_Type)TCC0_IRQn, 0);  // Make this highest priority
+  NVIC_EnableIRQ((IRQn_Type)TCC0_IRQn);       // Enable the interrupt
+  interrupts();
+}
+
+// Timer IRQ handlers replace the dummy handlers (in cortex_handlers)
+// copied from rf24 branch
+void TCC0_Handler() {
+    if(TCC0->INTFLAG.bit.OVF) {
+        TCC0->INTFLAG.bit.OVF = 1; // writing a 1 clears the flag
+        interruptHandler();
+    }
+}
+
+void TCC1_Handler() {
+    if(TCC1->INTFLAG.bit.OVF) {
+        TCC1->INTFLAG.bit.OVF = 1; // writing a 1 clears the flag
+        interruptHandler();
+    }
+}
+
+void TCC2_Handler() {
+    if(TCC2->INTFLAG.bit.OVF) {
+        TCC2->INTFLAG.bit.OVF = 1; // writing a 1 clears the flag
+        interruptHandler();
+    }
+}
+
+
+bool DCCTimer::isPWMPin(byte pin) {
+  //TODO: SAMD whilst this call to digitalPinHasPWM will reveal which pins can do PWM,
+  //      there's no support yet for High Accuracy, so for now return false
+  //  return digitalPinHasPWM(pin);
+  return false;
+}
+
+void DCCTimer::setPWM(byte pin, bool high) {
+    // TODO: High Accuracy mode is not supported as yet, and may never need to be
+    (void) pin;
+    (void) high;
+}
+
+void DCCTimer::clearPWM() {
+  return;
+}
+
+void   DCCTimer::getSimulatedMacAddress(byte mac[6]) {
+  volatile uint32_t *serno1 = (volatile uint32_t *)0x0080A00C;
+  volatile uint32_t *serno2 = (volatile uint32_t *)0x0080A040;
+//  volatile uint32_t *serno3 = (volatile uint32_t *)0x0080A044;
+//  volatile uint32_t *serno4 = (volatile uint32_t *)0x0080A048;
+
+  volatile uint32_t m1 = *serno1;
+  volatile uint32_t m2 = *serno2;
+  mac[0] = m1 >> 8;
+  mac[1] = m1 >> 0;
+  mac[2] = m2 >> 24;
+  mac[3] = m2 >> 16;
+  mac[4] = m2 >> 8;
+  mac[5] = m2 >> 0;
+}
+
+volatile int DCCTimer::minimum_free_memory=__INT_MAX__;
+
+// Return low memory value... 
+int DCCTimer::getMinimumFreeMemory() {
+  noInterrupts(); // Disable interrupts to get volatile value 
+  int retval = freeMemory();
+  interrupts();
+  return retval;
+}
+
+extern "C" char* sbrk(int incr);
+
+int DCCTimer::freeMemory() {
+  char top;
+  return (int)(&top - reinterpret_cast<char *>(sbrk(0)));
+}
+
+#endif

EEStore.h

@@ -26,7 +26,7 @@
 
 #include <Arduino.h>
 
-#if defined(ARDUINO_ARCH_SAMD)
+#if defined(ARDUINO_ARCH_SAMC)
 #include <SparkFun_External_EEPROM.h>
 extern ExternalEEPROM EEPROM;
 #else

MotorDriver.cpp

@@ -1,4 +1,5 @@
 /*
+ *  © 2022 Paul M Antoine
  *  © 2021 Mike S
  *  © 2021 Fred Decker
  *  © 2020-2022 Harald Barth
@@ -172,8 +173,12 @@ int MotorDriver::mA2raw( unsigned int mA) {
 
 void  MotorDriver::getFastPin(const FSH* type,int pin, bool input, FASTPIN & result) {
     // DIAG(F("MotorDriver %S Pin=%d,"),type,pin);
-    (void) type; // avoid compiler warning if diag not used above. 
+    (void) type; // avoid compiler warning if diag not used above.
+#if defined(ARDUINO_ARCH_SAMD)
+    PortGroup *port = digitalPinToPort(pin);
+#else
     uint8_t port = digitalPinToPort(pin);
+#endif
     if (input)
       result.inout = portInputRegister(port);
     else

MotorDriver.h

@@ -1,4 +1,5 @@
 /*
+ *  © 2022 Paul M Antoine
  *  © 2021 Mike S
  *  © 2021 Fred Decker
  *  © 2020 Chris Harlow
@@ -36,7 +37,7 @@
 #define UNUSED_PIN 127 // inside int8_t
 #endif
 
-#if defined(__IMXRT1062__) || defined(ARDUINO_ARCH_ESP8266) || defined(ARDUINO_ARCH_ESP32)
+#if defined(__IMXRT1062__) || defined(ARDUINO_ARCH_ESP8266) || defined(ARDUINO_ARCH_ESP32) || defined(ARDUINO_ARCH_SAMD)
 struct FASTPIN {
   volatile uint32_t *inout;
   uint32_t maskHIGH;  

MotorDrivers.h

@@ -1,4 +1,5 @@
 /*
+ *  © 2022 Paul M Antoine
  *  © 2021 Fred Decker
  *  © 2020-2022 Harald Barth
  *  (c) 2020 Chris Harlow. All rights reserved.
@@ -50,6 +51,13 @@
                               new MotorDriver(3, 12, UNUSED_PIN, 9, A0, 2.99, 2000, UNUSED_PIN), \
                               new MotorDriver(11, 13, UNUSED_PIN, 8, A1, 2.99, 2000, UNUSED_PIN)
 
+// Setup for SAMD21 Sparkfun DEV board using Arduino standard Motor Shield R3 (MUST be R3 for 3v3 compatibility!!)
+// senseFactor for 3.3v systems is 1.95 as calculated when using 10-bit A/D samples,
+// and for 12-bit samples it's more like 0.488, but we probably need to tweak both these
+#define SAMD_STANDARD_MOTOR_SHIELD F("STANDARD_MOTOR_SHIELD"),                                             \
+                              new MotorDriver(3, 12, UNUSED_PIN, 9, A0, 1.95, 2000, UNUSED_PIN), \
+                              new MotorDriver(11, 13, UNUSED_PIN, 8, A1, 1.95, 2000, UNUSED_PIN)
+
 // Pololu Motor Shield
 #define POLOLU_MOTOR_SHIELD F("POLOLU_MOTOR_SHIELD"),                                                 \
                             new MotorDriver( 9, 7, UNUSED_PIN,         -4, A0, 18, 3000, 12), \

SerialManager.cpp

@@ -1,4 +1,5 @@
  /*
+ *  © 2022 Paul M Antoine
  *  © 2021 Chris Harlow
  *  © 2022 Harald Barth
  *  All rights reserved.
@@ -33,8 +34,13 @@ SerialManager::SerialManager(Stream * myserial) {
 
 void SerialManager::init() {
   while (!Serial && millis() < 5000); // wait max 5s for Serial to start
+#if defined(ARDUINO_ARCH_SAMD)
+  SerialUSB.begin(115200);
+  new SerialManager(&SerialUSB);
+#else
   Serial.begin(115200);
   new SerialManager(&Serial);
+#endif
 #ifdef SERIAL3_COMMANDS
   Serial3.begin(115200);
   new SerialManager(&Serial3);

defines.h

@@ -1,4 +1,5 @@
 /*
+ *  © 2022 Paul M Antoine
  *  © 2021 Neil McKechnie
  *  © 2021 Mike S
  *  © 2021 Fred Decker
@@ -40,7 +41,7 @@
 // WIFI_ON: All prereqs for running with WIFI are met
 // Note: WIFI_CHANNEL may not exist in early config.h files so is added here if needed.
 
-#if defined(ARDUINO_AVR_MEGA) || defined(ARDUINO_AVR_MEGA2560) || defined(ARDUINO_SAMD_ZERO) || defined(TEENSYDUINO) || defined(ARDUINO_AVR_NANO_EVERY) || defined(ARDUINO_ARCH_ESP8266) || defined(ARDUINO_ARCH_ESP32)
+#if defined(ARDUINO_AVR_MEGA) || defined(ARDUINO_AVR_MEGA2560) || defined(ARDUINO_SAMD_ZERO) || defined(TEENSYDUINO) || defined(ARDUINO_AVR_NANO_EVERY) || defined(ARDUINO_ARCH_ESP8266) || defined(ARDUINO_ARCH_ESP32) || defined(ARDUINO_ARCH_SAMD)
  #define BIG_RAM
 #endif 
 #if ENABLE_WIFI

platformio.ini

@@ -15,22 +15,35 @@ default_envs =
 	mega328
 	unowifiR2
 	nano
+	samd21-dev-usb
 src_dir = .
 include_dir = .
 
 [env]
 build_flags = -Wall -Wextra
 
-[env:samd21]
+[env:samd21-dev-usb]
 platform = atmelsam
 board = sparkfun_samd21_dev_usb
 framework = arduino
+upload_protocol = sam-ba
+lib_deps = 
+	${env.lib_deps}
+monitor_speed = 115200
+monitor_flags = --echo
+build_flags = -std=c++17 -DI2C_USE_WIRE -DDISABLE_EEPROM
+
+[env:samc21-firebox]
+platform = atmelsam
+board = firebox
+framework = arduino
 upload_protocol = atmel-ice
 lib_deps = 
 	${env.lib_deps}
 	SparkFun External EEPROM Arduino Library
 monitor_speed = 115200
 monitor_flags = --echo
+build_flags = -std=c++17 -DI2C_USE_WIRE -DDISABLE_EEPROM
 
 [env:mega2560-debug]
 platform = atmelavr