You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
250 lines
6.9 KiB
250 lines
6.9 KiB
/*
|
|
|
|
SoftwareSerial.cpp - Implementation of the Arduino software serial for ESP8266.
|
|
Copyright (c) 2015-2016 Peter Lerup. All rights reserved.
|
|
|
|
This library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
This library 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with this library; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
|
|
*/
|
|
|
|
#include <Arduino.h>
|
|
|
|
// The Arduino standard GPIO routines are not enough,
|
|
// must use some from the Espressif SDK as well
|
|
extern "C" {
|
|
#include "gpio.h"
|
|
}
|
|
|
|
#include <SoftwareSerial.h>
|
|
|
|
#define MAX_PIN 15
|
|
|
|
// As the Arduino attachInterrupt has no parameter, lists of objects
|
|
// and callbacks corresponding to each possible GPIO pins have to be defined
|
|
SoftwareSerial *ObjList[MAX_PIN+1];
|
|
|
|
void ICACHE_RAM_ATTR sws_isr_0() { ObjList[0]->rxRead(); };
|
|
void ICACHE_RAM_ATTR sws_isr_1() { ObjList[1]->rxRead(); };
|
|
void ICACHE_RAM_ATTR sws_isr_2() { ObjList[2]->rxRead(); };
|
|
void ICACHE_RAM_ATTR sws_isr_3() { ObjList[3]->rxRead(); };
|
|
void ICACHE_RAM_ATTR sws_isr_4() { ObjList[4]->rxRead(); };
|
|
void ICACHE_RAM_ATTR sws_isr_5() { ObjList[5]->rxRead(); };
|
|
// Pin 6 to 11 can not be used
|
|
void ICACHE_RAM_ATTR sws_isr_12() { ObjList[12]->rxRead(); };
|
|
void ICACHE_RAM_ATTR sws_isr_13() { ObjList[13]->rxRead(); };
|
|
void ICACHE_RAM_ATTR sws_isr_14() { ObjList[14]->rxRead(); };
|
|
void ICACHE_RAM_ATTR sws_isr_15() { ObjList[15]->rxRead(); };
|
|
|
|
static void (*ISRList[MAX_PIN+1])() = {
|
|
sws_isr_0,
|
|
sws_isr_1,
|
|
sws_isr_2,
|
|
sws_isr_3,
|
|
sws_isr_4,
|
|
sws_isr_5,
|
|
NULL,
|
|
NULL,
|
|
NULL,
|
|
NULL,
|
|
NULL,
|
|
NULL,
|
|
sws_isr_12,
|
|
sws_isr_13,
|
|
sws_isr_14,
|
|
sws_isr_15
|
|
};
|
|
|
|
SoftwareSerial::SoftwareSerial(int receivePin, int transmitPin, bool inverse_logic, unsigned int buffSize) {
|
|
m_oneWire = (receivePin == transmitPin);
|
|
m_rxValid = m_txValid = m_txEnableValid = false;
|
|
m_buffer = NULL;
|
|
m_invert = inverse_logic;
|
|
m_overflow = false;
|
|
m_rxEnabled = false;
|
|
if (isValidGPIOpin(receivePin)) {
|
|
m_rxPin = receivePin;
|
|
m_buffSize = buffSize;
|
|
m_buffer = (uint8_t*)malloc(m_buffSize);
|
|
if (m_buffer != NULL) {
|
|
m_rxValid = true;
|
|
m_inPos = m_outPos = 0;
|
|
pinMode(m_rxPin, INPUT);
|
|
ObjList[m_rxPin] = this;
|
|
}
|
|
}
|
|
if (isValidGPIOpin(transmitPin) || (!m_oneWire && (transmitPin == 16))) {
|
|
m_txValid = true;
|
|
m_txPin = transmitPin;
|
|
if (!m_oneWire) {
|
|
pinMode(m_txPin, OUTPUT);
|
|
digitalWrite(m_txPin, !m_invert);
|
|
}
|
|
}
|
|
// Default speed
|
|
begin(9600);
|
|
}
|
|
|
|
SoftwareSerial::~SoftwareSerial() {
|
|
enableRx(false);
|
|
if (m_rxValid)
|
|
ObjList[m_rxPin] = NULL;
|
|
if (m_buffer)
|
|
free(m_buffer);
|
|
}
|
|
|
|
bool SoftwareSerial::isValidGPIOpin(int pin) {
|
|
return (pin >= 0 && pin <= 5) || (pin >= 12 && pin <= MAX_PIN);
|
|
}
|
|
|
|
void SoftwareSerial::begin(long speed) {
|
|
// Use getCycleCount() loop to get as exact timing as possible
|
|
m_bitTime = F_CPU/speed;
|
|
// By default enable interrupt during tx only for low speed
|
|
m_intTxEnabled = speed < 9600;
|
|
|
|
if (!m_rxEnabled)
|
|
enableRx(true);
|
|
}
|
|
|
|
long SoftwareSerial::baudRate() {
|
|
return F_CPU/m_bitTime;
|
|
}
|
|
|
|
void SoftwareSerial::setTransmitEnablePin(int transmitEnablePin) {
|
|
if (isValidGPIOpin(transmitEnablePin)) {
|
|
m_txEnableValid = true;
|
|
m_txEnablePin = transmitEnablePin;
|
|
pinMode(m_txEnablePin, OUTPUT);
|
|
digitalWrite(m_txEnablePin, LOW);
|
|
} else {
|
|
m_txEnableValid = false;
|
|
}
|
|
}
|
|
|
|
void SoftwareSerial::enableIntTx(bool on) {
|
|
m_intTxEnabled = on;
|
|
}
|
|
|
|
void SoftwareSerial::enableTx(bool on) {
|
|
if (m_oneWire && m_txValid) {
|
|
if (on) {
|
|
enableRx(false);
|
|
digitalWrite(m_txPin, !m_invert);
|
|
pinMode(m_rxPin, OUTPUT);
|
|
} else {
|
|
digitalWrite(m_txPin, !m_invert);
|
|
pinMode(m_rxPin, INPUT);
|
|
enableRx(true);
|
|
}
|
|
delay(1); // it's important to have a delay after switching
|
|
}
|
|
}
|
|
|
|
void SoftwareSerial::enableRx(bool on) {
|
|
if (m_rxValid) {
|
|
if (on)
|
|
attachInterrupt(m_rxPin, ISRList[m_rxPin], m_invert ? RISING : FALLING);
|
|
else
|
|
detachInterrupt(m_rxPin);
|
|
m_rxEnabled = on;
|
|
}
|
|
}
|
|
|
|
int SoftwareSerial::read() {
|
|
if (!m_rxValid || (m_inPos == m_outPos)) return -1;
|
|
uint8_t ch = m_buffer[m_outPos];
|
|
m_outPos = (m_outPos+1) % m_buffSize;
|
|
return ch;
|
|
}
|
|
|
|
int SoftwareSerial::available() {
|
|
if (!m_rxValid) return 0;
|
|
int avail = m_inPos - m_outPos;
|
|
if (avail < 0) avail += m_buffSize;
|
|
return avail;
|
|
}
|
|
|
|
#define WAIT { while (ESP.getCycleCount()-start < wait) if (m_intTxEnabled) optimistic_yield(1); wait += m_bitTime; }
|
|
|
|
size_t SoftwareSerial::write(uint8_t b) {
|
|
if (!m_txValid) return 0;
|
|
|
|
if (m_invert) b = ~b;
|
|
if (!m_intTxEnabled)
|
|
// Disable interrupts in order to get a clean transmit
|
|
cli();
|
|
if (m_txEnableValid) digitalWrite(m_txEnablePin, HIGH);
|
|
unsigned long wait = m_bitTime;
|
|
digitalWrite(m_txPin, HIGH);
|
|
unsigned long start = ESP.getCycleCount();
|
|
// Start bit;
|
|
digitalWrite(m_txPin, LOW);
|
|
WAIT;
|
|
for (int i = 0; i < 8; i++) {
|
|
digitalWrite(m_txPin, (b & 1) ? HIGH : LOW);
|
|
WAIT;
|
|
b >>= 1;
|
|
}
|
|
// Stop bit
|
|
digitalWrite(m_txPin, HIGH);
|
|
WAIT;
|
|
if (m_txEnableValid) digitalWrite(m_txEnablePin, LOW);
|
|
if (!m_intTxEnabled)
|
|
sei();
|
|
return 1;
|
|
}
|
|
|
|
void SoftwareSerial::flush() {
|
|
m_inPos = m_outPos = 0;
|
|
}
|
|
|
|
bool SoftwareSerial::overflow() {
|
|
bool res = m_overflow;
|
|
m_overflow = false;
|
|
return res;
|
|
}
|
|
|
|
int SoftwareSerial::peek() {
|
|
if (!m_rxValid || (m_inPos == m_outPos)) return -1;
|
|
return m_buffer[m_outPos];
|
|
}
|
|
|
|
void ICACHE_RAM_ATTR SoftwareSerial::rxRead() {
|
|
// Advance the starting point for the samples but compensate for the
|
|
// initial delay which occurs before the interrupt is delivered
|
|
unsigned long wait = m_bitTime + m_bitTime/3 - 500;
|
|
unsigned long start = ESP.getCycleCount();
|
|
uint8_t rec = 0;
|
|
for (int i = 0; i < 8; i++) {
|
|
WAIT;
|
|
rec >>= 1;
|
|
if (digitalRead(m_rxPin))
|
|
rec |= 0x80;
|
|
}
|
|
if (m_invert) rec = ~rec;
|
|
// Stop bit
|
|
WAIT;
|
|
// Store the received value in the buffer unless we have an overflow
|
|
unsigned int next = (m_inPos+1) % m_buffSize;
|
|
if (next != m_outPos) {
|
|
m_buffer[m_inPos] = rec;
|
|
m_inPos = next;
|
|
} else {
|
|
m_overflow = true;
|
|
}
|
|
// Must clear this bit in the interrupt register,
|
|
// it gets set even when interrupts are disabled
|
|
GPIO_REG_WRITE(GPIO_STATUS_W1TC_ADDRESS, 1 << m_rxPin);
|
|
}
|
|
|