/*
* © 2021 Mike S
* © 2021-2022 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 UNO or MEGA
// Please refer to DCCTimer.h for general comments about how this class works
// This is to avoid repetition and duplication.
#ifdef ARDUINO_ARCH_AVR
#include <avr/boot.h>
#include <avr/wdt.h>
#include "DCCTimer.h"
INTERRUPT_CALLBACK interruptHandler=0;
// Arduino nano, uno, mega etc
#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
#define TIMER1_A_PIN 11
#define TIMER1_B_PIN 12
#define TIMER1_C_PIN 13
#else
#define TIMER1_A_PIN 9
#define TIMER1_B_PIN 10
#endif
void DCCTimer::begin(INTERRUPT_CALLBACK callback) {
interruptHandler=callback;
noInterrupts();
TCCR1A = 0;
ICR1 = CLOCK_CYCLES;
TCNT1 = 0;
TCCR1B = _BV(WGM13) | _BV(CS10); // Mode 8, clock select 1
TIMSK1 = _BV(TOIE1); // Enable Software interrupt
interrupts();
}
// ISR called by timer interrupt every 58uS
ISR(TIMER1_OVF_vect){ interruptHandler(); }
// Alternative pin manipulation via PWM control.
bool DCCTimer::isPWMPin(byte pin) {
return pin==TIMER1_A_PIN
|| pin==TIMER1_B_PIN
#ifdef TIMER1_C_PIN
|| pin==TIMER1_C_PIN
#endif
;
}
void DCCTimer::setPWM(byte pin, bool high) {
if (pin==TIMER1_A_PIN) {
TCCR1A |= _BV(COM1A1);
OCR1A= high?1024:0;
}
else if (pin==TIMER1_B_PIN) {
TCCR1A |= _BV(COM1B1);
OCR1B= high?1024:0;
}
#ifdef TIMER1_C_PIN
else if (pin==TIMER1_C_PIN) {
TCCR1A |= _BV(COM1C1);
OCR1C= high?1024:0;
}
#endif
}
void DCCTimer::clearPWM() {
TCCR1A= 0;
}
void DCCTimer::getSimulatedMacAddress(byte mac[6]) {
for (byte i=0; i<6; i++) {
// take the fist 3 and last 3 of the serial.
// the first 5 of 8 are at 0x0E to 0x013
// the last 3 of 8 are at 0x15 to 0x017
mac[i]=boot_signature_byte_get(0x0E + i + (i>2? 4 : 0));
}
mac[0] &= 0xFE;
mac[0] |= 0x02;
}
volatile int DCCTimer::minimum_free_memory=__INT_MAX__;
// Return low memory value...
int DCCTimer::getMinimumFreeMemory() {
noInterrupts(); // Disable interrupts to get volatile value
int retval = minimum_free_memory;
interrupts();
return retval;
}
extern char *__brkval;
extern char *__malloc_heap_start;
int DCCTimer::freeMemory() {
char top;
return __brkval ? &top - __brkval : &top - __malloc_heap_start;
}
void DCCTimer::reset() {
wdt_enable( WDTO_15MS); // set Arduino watchdog timer for 15ms
delay(50); // wait for the prescaller time to expire
}
#if defined(ARDUINO_AVR_MEGA) || defined(ARDUINO_AVR_MEGA2560)
#define NUM_ADC_INPUTS 16
#else
#define NUM_ADC_INPUTS 8
#endif
uint16_t ADCee::usedpins = 0;
int * ADCee::analogvals = NULL;
byte *ADCee::idarr = NULL;
static bool ADCusesHighPort = false;
/*
* Register a new pin to be scanned
* Returns current reading of pin and
* stores that as well
*/
int ADCee::init(uint8_t pin) {
uint8_t id = pin - A0;
byte n;
if (id >= NUM_ADC_INPUTS)
return -1023;
if (id > 7)
ADCusesHighPort = true;
pinMode(pin, INPUT);
int value = analogRead(pin);
if (analogvals == NULL) {
analogvals = (int *)calloc(NUM_ADC_INPUTS, sizeof(int));
for (n=0 ; n < NUM_ADC_INPUTS; n++) // set unreasonable value at startup as marker
analogvals[n] = -32768; // 16 bit int min value
idarr = (byte *)calloc(NUM_ADC_INPUTS+1, sizeof(byte)); // +1 for terminator value
for (n=0 ; n <= NUM_ADC_INPUTS; n++)
idarr[n] = 255; // set 255 as end of array marker
}
analogvals[id] = value; // store before enable by idarr[n]
for (n=0 ; n <= NUM_ADC_INPUTS; n++) {
if (idarr[n] == 255) {
idarr[n] = id;
break;
}
}
return value;
}
int16_t ADCee::ADCmax() {
return 1023;
}
/*
* Read function ADCee::read(pin) to get value instead of analogRead(pin)
*/
int ADCee::read(uint8_t pin, bool fromISR) {
(void)fromISR; // AVR does ignore this arg
uint8_t id = pin - A0;
int a;
// we do not need to check (analogvals == NULL)
// because usedpins would still be 0 in that case
noInterrupts();
a = analogvals[id];
interrupts();
return a;
}
/*
* Scan function that is called from interrupt
*/
#pragma GCC push_options
#pragma GCC optimize ("-O3")
void ADCee::scan() {
static byte num = 0; // index into id array
static bool waiting = false;
if (waiting) {
// look if we have a result
byte low, high;
if (bit_is_set(ADCSRA, ADSC))
return; // no result, continue to wait
// found value
low = ADCL; //must read low before high
high = ADCH;
bitSet(ADCSRA, ADIF);
analogvals[idarr[num]] = (high << 8) | low;
waiting = false;
}
if (!waiting) {
// cycle around in-use analogue pins
num++;
if (idarr[num] == 255)
num = 0;
// start new ADC aquire on id
#if defined(ADCSRB) && defined(MUX5)
if (ADCusesHighPort) { // if we ever have started to use high pins)
if (idarr[num] > 7) // if we use a high ADC pin
bitSet(ADCSRB, MUX5); // set MUX5 bit
else
bitClear(ADCSRB, MUX5);
}
#endif
ADMUX = (1 << REFS0) | (idarr[num] & 0x07); // select AVCC as reference and set MUX
bitSet(ADCSRA, ADSC); // start conversion
waiting = true;
}
}
#pragma GCC pop_options
void ADCee::begin() {
noInterrupts();
// ADCSRA = (ADCSRA & 0b11111000) | 0b00000100; // speed up analogRead sample time
// Set up ADC for free running mode
ADMUX=(1<<REFS0); //select AVCC as reference. We set MUX later
ADCSRA = (1<<ADEN)|(1 << ADPS2); // ADPS2 means divisor 32 and 16Mhz/32=500kHz.
//bitSet(ADCSRA, ADSC); //do not start the ADC yet. Done when we have set the MUX
interrupts();
}
#endif