Commit 7e48d847 authored by Eric Duminil's avatar Eric Duminil
Browse files

Trying to replace SoftwareSerial

with lower footprint
Broken
parent da3bcf5a
......@@ -18,7 +18,7 @@ namespace config {
}
#if defined(ESP8266)
# include "src/lib/EspSoftwareSerial/SoftwareSerial.h"
# include "src/lib/Esp8266EdgeSoftwareSerial/SoftwareSerial.h"
# define S8_RX_PIN 13 // GPIO13, a.k.a. D7, connected to S8 Tx pin.
# define S8_TX_PIN 15 // GPIO15, a.k.a. D8, connected to S8 Rx pin.
SoftwareSerial S8_serial(S8_RX_PIN, S8_TX_PIN);
......
MIT License
Copyright (c) 2019 Rob Miles
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
# Esp8266EdgeSoftwareSerial
Software serial for the ESP8266 that uses edge triggered interrupts to improve performance.
Incoming characters do not block programs for the time it takes them to arrive, leading to signficant performance improvements when used on serial data ports running at speeds of 9600 baud or less. Note that the slower the data rate, the more useful this driver becomes. For high speeds it doesn't confer as much of an advantage.
You can drop the files into your Arduino sketch folder and use them as straight replacements for the SoftwareSerial library files. Simply replace the < and > characters with double quote characters in the include statement to use the new library:
```c++
#include <SoftwareSerial.h>
```
with
```c++
#include "SoftwareSerial.h"
```
To use the edge triggered operation add an extra parameter to the constructor for your software serial object:
```c++
SoftwareSerial gpsSerial = new SoftwareSerial(12, -1, false, 128, true);
```
The above statement creates a gps receiver that listens on pin 12 but does not transmit anything (that's what the -1 means in the constructor).
The data is not inverted (that's what false means) and it is using a 128 byte buffer for incoming characters.
The final parameter (which is true in the above code) selects edge operation.
If you leave the final parameter off your constructor the SoftwareSerial library works in exaclty the same way as the original library. In other words it defaults to non-edge operation.
# Late charcters
There is one issue with this implmenentation. It is not guaranteed that the last character of a sequence of characters will be detected when it arrives. This happens because the driver needs to detect a signal change to detect data and some values don't have a signal change at their end.
The "late" character will be registered when the next character arrives. This is not a problem for devices such as GPS sensors and Air Quality sensors as these transmit data continuously, but it would be an issue if you used this mechanism on a user terminal connection. Having said that, you would not need to use edge triggering on such an interface, as your user will not type so quickly and continuously as to cause a problem.
Rob Miles
/*
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 boolean SerialBusy = false;
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, bool edge_triggered) {
m_oneWire = (receivePin == transmitPin);
m_rxValid = m_txValid = m_txEnableValid = false;
m_buffer = NULL;
m_invert = inverse_logic;
m_edge = edge_triggered;
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) {
if (m_edge)
attachInterrupt(m_rxPin, ISRList[m_rxPin], CHANGE); // fire at rising and falling edges
else
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];
}
inline bool SoftwareSerial::propgateBits(bool level, int pulseBitLength)
{
for (int i = 0; i < pulseBitLength; i++)
{
m_rec >>= 1;
if (level)
m_rec |= 0x80;
m_bitNo++;
if (m_bitNo == 8)
{
return true;
}
}
return false;
}
inline void SoftwareSerial::setWaitingForStart()
{
m_getByteState = awaitingStart;
}
inline void SoftwareSerial::setStartBit(unsigned long start)
{
// mark - the start of a pulse
// set the timers and wait for the next pulse
m_byteStart = start;
m_pulseStart = start;
m_rec = 0;
m_bitNo = 0;
m_getByteState = gotStart;
}
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();
if (m_edge) {
// Get the rxLevel and convert for inverted input
bool rxLevel;
if (m_invert)
rxLevel = !digitalRead(m_rxPin);
else
rxLevel = digitalRead(m_rxPin);
unsigned long byteTime;
float byteBitLengthFloat;
int byteBitLength;
unsigned long pulseTime;
float pulseBitLengthFloat;
int pulseBitLength;
bool previousBit = !rxLevel;
bool gotByte = false;
switch (m_getByteState)
{
case awaitingStart:
if (!rxLevel)
{
setStartBit(start);
}
break;
case gotStart:
byteTime = start - m_byteStart;
byteBitLengthFloat = (float)byteTime / m_bitTime;
byteBitLength = (int)(byteBitLengthFloat + 0.5);
pulseTime = start - m_pulseStart;
pulseBitLengthFloat = (float)pulseTime / m_bitTime;
pulseBitLength = (int)(pulseBitLengthFloat + 0.5);
// don't want to add the start bit into the value
if (propgateBits(previousBit, pulseBitLength - 1))
{
// store byte in buffer
int next = (m_inPos + 1) % m_buffSize;
if (next != m_outPos) {
m_buffer[m_inPos] = m_rec;
m_inPos = next;
}
else {
m_overflow = true;
}
setWaitingForStart();
return;
}
m_pulseStart = start;
m_getByteState = readingBits;
break;
case readingBits:
byteTime = start - m_byteStart;
byteBitLengthFloat = (float)byteTime / m_bitTime;
byteBitLength = (int)(byteBitLengthFloat + 0.5);
pulseTime = start - m_pulseStart;
pulseBitLengthFloat = (float)pulseTime / m_bitTime;
pulseBitLength = (int)(pulseBitLengthFloat + 0.5);
if (byteBitLength > 9)
{
// fill in the last bits with high values
// because this is the start bit of the next byte
propgateBits(true, 8);
// store the byte in the buffer
int next = (m_inPos + 1) % m_buffSize;
if (next != m_outPos) {
m_buffer[m_inPos] = m_rec;
m_inPos = next;
}
else {
m_overflow = true;
}
setStartBit(start);
}
else
{
if (propgateBits(previousBit, pulseBitLength))
{
// Store the received value in the buffer unless we have an overflow
int next = (m_inPos + 1) % m_buffSize;
if (next != m_outPos) {
m_buffer[m_inPos] = m_rec;
m_inPos = next;
}
else {
m_overflow = true;
}
setWaitingForStart();
}
}
m_pulseStart = start;
break;
}
}
else
{
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
int next = (m_inPos + 1) % m_buffSize;
if (next != m_inPos) {
m_buffer[m_inPos] = rec;
m_inPos = next;
}
}
// 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);
}
/*
SoftwareSerial.h
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
*/
#ifndef SoftwareSerial_h
#define SoftwareSerial_h
#include <inttypes.h>
#include <Stream.h>
// This class is compatible with the corresponding AVR one,
// the constructor however has an optional rx buffer size.
// Speed up to 115200 can be used.
class SoftwareSerial : public Stream {
public:
SoftwareSerial(int receivePin, int transmitPin, bool inverse_logic = false, unsigned int buffSize = 64, bool edge_triggered = false);
virtual ~SoftwareSerial();
void begin(long speed);
long baudRate();
// Transmit control pin
void setTransmitEnablePin(int transmitEnablePin);
// Enable or disable interrupts during tx
void enableIntTx(bool on);
bool overflow();
int peek();
virtual size_t write(uint8_t byte);
virtual int read();
virtual int available();
virtual void flush();
operator bool() {return m_rxValid || m_txValid;}
// Disable or enable interrupts on the rx pin
void enableRx(bool on);
// One wire control
void enableTx(bool on);
void rxRead();
volatile boolean SerialBusy = false;
// AVR compatibility methods
bool listen() { enableRx(true); return true; }
void end() { stopListening(); }
bool isListening() { return m_rxEnabled; }
bool stopListening() { enableRx(false); return true; }
using Print::write;
void setWaitingForStart();
void setStartBit(unsigned long start);
bool propgateBits(bool level, int pulseBitLength);
private:
bool isValidGPIOpin(int pin);
// Member variables
bool m_edge;
bool m_oneWire;
int m_rxPin, m_txPin, m_txEnablePin;
bool m_rxValid, m_rxEnabled;
bool m_txValid, m_txEnableValid;
bool m_invert;
bool m_overflow;
unsigned long m_bitTime;
bool m_intTxEnabled;
unsigned int m_inPos, m_outPos;
int m_buffSize;
uint8_t *m_buffer;
// Edge detection management
enum GetByteState { awaitingStart, gotStart, readingBits };
volatile GetByteState m_getByteState = awaitingStart;
volatile unsigned long m_byteStart;
volatile unsigned long m_pulseStart;
volatile uint8_t m_rec = 0;
volatile uint8_t m_bitNo = 0;
};
// If only one tx or rx wanted then use this as parameter for the unused pin
#define SW_SERIAL_UNUSED_PIN -1
#endif
This diff is collapsed.
# EspSoftwareSerial
## Implementation of the Arduino software serial library for the ESP8266 / ESP32 family
This fork implements interrupt service routine best practice.
In the receive interrupt, instead of blocking for whole bytes
at a time - voiding any near-realtime behavior of the CPU - only level
change and timestamp are recorded. The more time consuming phase
detection and byte assembly are done in the main code.
Except at high bitrates, depending on other ongoing activity,
interrupts in particular, this software serial adapter
supports full duplex receive and send. At high bitrates (115200bps)
send bit timing can be improved at the expense of blocking concurrent
full duplex receives, with the `SoftwareSerial::enableIntTx(false)` function call.
The same functionality is given as the corresponding AVR library but
several instances can be active at the same time. Speed up to 115200 baud
is supported. Besides a constructor compatible to the AVR SoftwareSerial class,
and updated constructor that takes no arguments exists, instead the `begin()`
function can handle the pin assignments and logic inversion.
It also has optional input buffer capacity arguments for byte buffer and ISR bit buffer.
This way, it is a better drop-in replacement for the hardware serial APIs on the ESP MCUs.
Please note that due to the fact that the ESPs always have other activities
ongoing, there will be some inexactness in interrupt timings. This may
lead to inevitable, but few, bit errors when having heavy data traffic
at high baud rates.
This library supports ESP8266, ESP32, ESP32-S2 and ESP32-C3 devices.
## Resource optimization
The memory footprint can be optimized to just fit the amount of expected
incoming asynchronous data.
For this, the `SoftwareSerial` constructor provides two arguments. First, the
octet buffer capacity for assembled received octets can be set. Read calls are
satisfied from this buffer, freeing it in return.
Second, the signal edge detection buffer of 32bit fields can be resized.
One octet may require up to to 10 fields, but fewer may be needed,
depending on the bit pattern. Any read or write calls check this buffer
to assemble received octets, thus promoting completed octets to the octet
buffer, freeing fields in the edge detection buffer.
Look at the swsertest.ino example. There, on reset, ASCII characters ' ' to 'z'
are sent. This happens not as a block write, but in a single write call per
character. As the example uses a local loopback wire, every outgoing bit is
immediately received back. Therefore, any single write call causes up to
10 fields - depending on the exact bit pattern - to be occupied in the signal
edge detection buffer. In turn, as explained before, each single write call
also causes received bit assembly to be performed, promoting these bits from
the signal edge detection buffer to the octet buffer as soon as possible.
Explaining by way of contrast, if during a a single write call, perhaps because
of using block writing, more than a single octet is received, there will be a
need for more than 10 fields in the signal edge detection buffer.
The necessary capacity of the octet buffer only depends on the amount of incoming
data until the next read call.
For the swsertest.ino example, this results in the following optimized
constructor arguments to spend only the minimum RAM on buffers required:
The octet buffer capacity (`bufCapacity`) is 95 (93 characters net plus two tolerance).
The signal edge detection buffer capacity (`isrBufCapacity`) is 11, as each
single octet can have up to 11 bits on the wire,
which are immediately received during the write, and each
write call causes the signal edge detection to promote the previously sent and
received bits to the octet buffer.
In a more generalized scenario, calculate the bits (use message size in octets
times 10) that may be asynchronously received to determine the value for
`isrBufCapacity` in the constructor. Also use the number of received octets
that must be buffered for reading as the value of `bufCapacity`.
The more frequently your code calls write or read functions, the greater the
chances are that you can reduce the `isrBufCapacity` footprint without losing data,
and each time you call read to fetch from the octet buffer, you reduce the
need for space there.
## SoftwareSerialConfig and parity
The configuration of the data stream is done via a `SoftwareSerialConfig`
argument to `begin()`. Word lengths can be set to between 5 and 8 bits, parity
can be N(one), O(dd) or E(ven) and 1 or 2 stop bits can be used. The default is
`SWSERIAL_8N1` using 8 bits, no parity and 1 stop bit but any combination can
be used, e.g. `SWSERIAL_7E2`. If using EVEN or ODD parity, any parity errors
can be detected with the `readParity()` and `parityEven()` or `parityOdd()`
functions respectively. Note that the result of `readParity()` always applies
to the preceding `read()` or `peek()` call, and is undefined if they report
no data or an error.
To allow flexible 9-bit and data/addressing protocols, the additional parity
modes MARK and SPACE are also available. Furthermore, the parity mode can be
individually set in each call to `write()`.
This allows a simple implementation of protocols where the parity bit is used to
distinguish between data and addresses/commands ("9-bit" protocols). First set
up SoftwareSerial with parity mode SPACE, e.g. `SWSERIAL_8S1`. This will add a
parity bit to every byte sent, setting it to logical zero (SPACE parity).
To detect incoming bytes with the parity bit set (MARK parity), use the
`readParity()` function. To send a byte with the parity bit set, just add
`MARK` as the second argument when writing, e.g. `write(ch, SWSERIAL_PARITY_MARK)`.
## Checking for correct pin selection / configuration
In general, most pins on the ESP8266 and ESP32 devices can be used by SoftwareSerial,
however each device has a number of pins that have special functions or require careful
handling to prevent undesirable situations, for example they are connected to the
on-board SPI flash memory or they are used to determine boot and programming modes
after powerup or brownouts. These pins are not able to be configured by this library.
The exact list for each device can be found in the
[ESP32 data sheet](https://www.espressif.com/sites/default/files/documentation/esp32_datasheet_en.pdf)
in sections 2.2 (Pin Descriptions) and 2.4 (Strapping pins). There is a discussion
dedicated to the use of GPIO12 in this
[note about GPIO12](https://github.com/espressif/esp-idf/tree/release/v3.2/examples/storage/sd_card#note-about-gpio12).
Refer to the `isValidGPIOpin()`, `isValidRxGPIOpin()` and `isValidTxGPIOpin()`
functions for the GPIO restrictions enforced by this library by default.
The easiest and safest method is to test the object returned at runtime, to see if
it is valid. For example:
```
#include <SoftwareSerial.h>
#define MYPORT_TX 12
#define MYPORT_RX 13
SoftwareSerial myPort;
[...]
Serial.begin(115200); // Standard hardware serial port
myPort.begin(38400, SWSERIAL_8N1, MYPORT_RX, MYPORT_TX, false);
if (!myPort) { // If the object did not initialize, then its configuration is invalid
Serial.println("Invalid SoftwareSerial pin configuration, check config");
while (1) { // Don't continue with invalid configuration
delay (1000);
}
}
[...]
```
## Using and updating EspSoftwareSerial in the esp8266com/esp8266 Arduino build environment
EspSoftwareSerial is both part of the BSP download for ESP8266 in Arduino,
and it is set up as a Git submodule in the esp8266 source tree,
specifically in `.../esp8266/libraries/SoftwareSerial` when using a Github
repository clone in your Arduino sketchbook hardware directory.
This supersedes any version of EspSoftwareSerial installed for instance via
the Arduino library manager, it is not required to install EspSoftwareSerial
for the ESP8266 separately at all, but doing so has ill effect.
The responsible maintainer of the esp8266 repository has kindly shared the
following command line instructions to use, if one wishes to manually
update EspSoftwareSerial to a newer release than pulled in via the ESP8266 Arduino BSP:
To update esp8266/arduino SoftwareSerial submodule to lastest master:
Clean it (optional):
```shell
$ rm -rf libraries/SoftwareSerial
$ git submodule update --init
```
Now update it:
```shell
$ cd libraries/SoftwareSerial
$ git checkout master
$ git pull
```
/*
SoftwareSerial.cpp - Implementation of the Arduino software serial for ESP8266/ESP32.
Copyright (c) 2015-2016 Peter Lerup. All rights reserved.
Copyright (c) 2018-2019 Dirk O. Kaar. 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 "SoftwareSerial.h"
#include <Arduino.h>
#ifndef ESP32
uint32_t SoftwareSerial::m_savedPS = 0;
#else
portMUX_TYPE SoftwareSerial::m_interruptsMux = portMUX_INITIALIZER_UNLOCKED;
#endif
inline void IRAM_ATTR SoftwareSerial::disableInterrupts()
{
#ifndef ESP32
m_savedPS = xt_rsil(15);
#else
taskENTER_CRITICAL(&m_interruptsMux);
#endif
}
inline void IRAM_ATTR SoftwareSerial::restoreInterrupts()
{
#ifndef ESP32
xt_wsr_ps(m_savedPS);
#else
taskEXIT_CRITICAL(&m_interruptsMux);
#endif
}
constexpr uint8_t BYTE_ALL_BITS_SET = ~static_cast<uint8_t>(0);
SoftwareSerial::SoftwareSerial() {
m_isrOverflow = false;
m_rxGPIOPullupEnabled = true;
}
SoftwareSerial::SoftwareSerial(int8_t rxPin, int8_t txPin, bool invert)
{
m_isrOverflow = false;
m_rxGPIOPullupEnabled = true;
m_rxPin = rxPin;
m_txPin = txPin;
m_invert = invert;
}
SoftwareSerial::~SoftwareSerial() {
end();
}
bool SoftwareSerial::isValidGPIOpin(int8_t pin) {
#if defined(ESP8266)
return (pin >= 0 && pin <= 16) && !isFlashInterfacePin(pin);
#elif defined(ESP32)
// Remove the strapping pins as defined in the datasheets, they affect bootup and other critical operations
// Remmove the flash memory pins on related devices, since using these causes memory access issues.
#ifdef CONFIG_IDF_TARGET_ESP32
// Datasheet https://www.espressif.com/sites/default/files/documentation/esp32_datasheet_en.pdf,
// Pinout https://docs.espressif.com/projects/esp-idf/en/latest/esp32/_images/esp32-devkitC-v4-pinout.jpg
return (pin == 1) || (pin >= 3 && pin <= 5) ||
(pin >= 12 && pin <= 15) ||
(!psramFound() && pin >= 16 && pin <= 17) ||
(pin >= 18 && pin <= 19) ||
(pin >= 21 && pin <= 23) || (pin >= 25 && pin <= 27) || (pin >= 32 && pin <= 39);
#elif CONFIG_IDF_TARGET_ESP32S2
// Datasheet https://www.espressif.com/sites/default/files/documentation/esp32-s2_datasheet_en.pdf,
// Pinout https://docs.espressif.com/projects/esp-idf/en/latest/esp32s2/_images/esp32-s2_saola1-pinout.jpg
return (pin >= 1 && pin <= 21) || (pin >= 33 && pin <= 44);
#elif CONFIG_IDF_TARGET_ESP32C3
// Datasheet https://www.espressif.com/sites/default/files/documentation/esp32-c3_datasheet_en.pdf,
// Pinout https://docs.espressif.com/projects/esp-idf/en/latest/esp32c3/_images/esp32-c3-devkitm-1-v1-pinout.jpg
return (pin >= 0 && pin <= 1) || (pin >= 3 && pin <= 7) || (pin >= 18 && pin <= 21);
#else
return true;
#endif
#else
return true;
#endif
}
bool SoftwareSerial::isValidRxGPIOpin(int8_t pin) {
return isValidGPIOpin(pin)
#if defined(ESP8266)
&& (pin != 16)
#endif
;
}
bool SoftwareSerial::isValidTxGPIOpin(int8_t pin) {
return isValidGPIOpin(pin)
#if defined(ESP32)
#ifdef CONFIG_IDF_TARGET_ESP32
&& (pin < 34)
#elif CONFIG_IDF_TARGET_ESP32S2
&& (pin <= 45)
#elif CONFIG_IDF_TARGET_ESP32C3
// no restrictions
#endif
#endif
;
}
bool SoftwareSerial::hasRxGPIOPullUp(int8_t pin) {
#if defined(ESP32)
return !(pin >= 34 && pin <= 39);
#else
(void)pin;
return true;
#endif
}
void SoftwareSerial::setRxGPIOPullUp() {
if (m_rxValid) {
pinMode(m_rxPin, hasRxGPIOPullUp(m_rxPin) && m_rxGPIOPullupEnabled ? INPUT_PULLUP : INPUT);
}
}
void SoftwareSerial::begin(uint32_t baud, SoftwareSerialConfig config,
int8_t rxPin, int8_t txPin,
bool invert, int bufCapacity, int isrBufCapacity) {
if (-1 != rxPin) m_rxPin = rxPin;
if (-1 != txPin) m_txPin = txPin;
m_oneWire = (m_rxPin == m_txPin);
m_invert = invert;
m_dataBits = 5 + (config & 07);
m_parityMode = static_cast<SoftwareSerialParity>(config & 070);
m_stopBits = 1 + ((config & 0300) ? 1 : 0);
m_pduBits = m_dataBits + static_cast<bool>(m_parityMode) + m_stopBits;
m_bitCycles = (ESP.getCpuFreqMHz() * 1000000UL + baud / 2) / baud;
m_intTxEnabled = true;
if (isValidRxGPIOpin(m_rxPin)) {
m_buffer.reset(new circular_queue<uint8_t>((bufCapacity > 0) ? bufCapacity : 64));
if (m_parityMode)
{
m_parityBuffer.reset(new circular_queue<uint8_t>((m_buffer->capacity() + 7) / 8));
m_parityInPos = m_parityOutPos = 1;
}
m_isrBuffer.reset(new circular_queue<uint32_t, SoftwareSerial*>((isrBufCapacity > 0) ?
isrBufCapacity : m_buffer->capacity() * (2 + m_dataBits + static_cast<bool>(m_parityMode))));
if (m_buffer && (!m_parityMode || m_parityBuffer) && m_isrBuffer) {
m_rxValid = true;
setRxGPIOPullUp();
}
}
if (isValidTxGPIOpin(m_txPin)) {
m_txValid = true;
if (!m_oneWire) {
pinMode(m_txPin, OUTPUT);
digitalWrite(m_txPin, !m_invert);
}
}
if (!m_rxEnabled) { enableRx(true); }
}
void SoftwareSerial::end()
{
enableRx(false);
m_txValid = false;
if (m_buffer) {
m_buffer.reset();
}
m_parityBuffer.reset();
if (m_isrBuffer) {
m_isrBuffer.reset();
}
}
uint32_t SoftwareSerial::baudRate() {
return ESP.getCpuFreqMHz() * 1000000UL / m_bitCycles;
}
void SoftwareSerial::setTransmitEnablePin(int8_t txEnablePin) {
if (isValidTxGPIOpin(txEnablePin)) {
m_txEnableValid = true;
m_txEnablePin = txEnablePin;
pinMode(m_txEnablePin, OUTPUT);
digitalWrite(m_txEnablePin, LOW);
}
else {
m_txEnableValid = false;
}
}
void SoftwareSerial::enableIntTx(bool on) {
m_intTxEnabled = on;
}
void SoftwareSerial::enableRxGPIOPullup(bool on) {
m_rxGPIOPullupEnabled = on;
setRxGPIOPullUp();
}
void SoftwareSerial::enableTx(bool on) {
if (m_txValid && m_oneWire) {
if (on) {
enableRx(false);
pinMode(m_txPin, OUTPUT);
digitalWrite(m_txPin, !m_invert);
}
else {
setRxGPIOPullUp();
enableRx(true);
}
}
}
void SoftwareSerial::enableRx(bool on) {
if (m_rxValid) {
if (on) {
m_rxLastBit = m_pduBits - 1;
// Init to stop bit level and current cycle
m_isrLastCycle = (ESP.getCycleCount() | 1) ^ m_invert;
if (m_bitCycles >= (ESP.getCpuFreqMHz() * 1000000UL) / 74880UL)
attachInterruptArg(digitalPinToInterrupt(m_rxPin), reinterpret_cast<void (*)(void*)>(rxBitISR), this, CHANGE);
else
attachInterruptArg(digitalPinToInterrupt(m_rxPin), reinterpret_cast<void (*)(void*)>(rxBitSyncISR), this, m_invert ? RISING : FALLING);
}
else {
detachInterrupt(digitalPinToInterrupt(m_rxPin));
}
m_rxEnabled = on;
}
}
int SoftwareSerial::read() {
if (!m_rxValid) { return -1; }
if (!m_buffer->available()) {
rxBits();
if (!m_buffer->available()) { return -1; }
}
auto val = m_buffer->pop();
if (m_parityBuffer)
{
m_lastReadParity = m_parityBuffer->peek() & m_parityOutPos;
m_parityOutPos <<= 1;
if (!m_parityOutPos)
{
m_parityOutPos = 1;
m_parityBuffer->pop();
}
}
return val;
}
int SoftwareSerial::read(uint8_t* buffer, size_t size) {
if (!m_rxValid) { return 0; }
int avail;
if (0 == (avail = m_buffer->pop_n(buffer, size))) {
rxBits();
avail = m_buffer->pop_n(buffer, size);
}
if (!avail) return 0;
if (m_parityBuffer) {
uint32_t parityBits = avail;
while (m_parityOutPos >>= 1) ++parityBits;
m_parityOutPos = (1 << (parityBits % 8));
m_parityBuffer->pop_n(nullptr, parityBits / 8);
}
return avail;
}
size_t SoftwareSerial::readBytes(uint8_t* buffer, size_t size) {
if (!m_rxValid || !size) { return 0; }
size_t count = 0;
auto start = millis();
do {
auto readCnt = read(&buffer[count], size - count);
count += readCnt;
if (count >= size) break;
if (readCnt) start = millis();
else optimistic_yield(1000UL);
} while (millis() - start < _timeout);
return count;
}
int SoftwareSerial::available() {
if (!m_rxValid) { return 0; }
rxBits();
int avail = m_buffer->available();
if (!avail) {
optimistic_yield(10000UL);
}
return avail;
}
void IRAM_ATTR SoftwareSerial::preciseDelay(bool sync) {
if (!sync)
{
// Reenable interrupts while delaying to avoid other tasks piling up
if (!m_intTxEnabled) { restoreInterrupts(); }
const auto expired = ESP.getCycleCount() - m_periodStart;
const int32_t remaining = m_periodDuration - expired;
const int32_t ms = remaining > 0 ? remaining / 1000L / static_cast<int32_t>(ESP.getCpuFreqMHz()) : 0;
if (ms > 0)
{
delay(ms);
}
else
{
optimistic_yield(10000UL);
}
}
while ((ESP.getCycleCount() - m_periodStart) < m_periodDuration) {}
// Disable interrupts again if applicable
if (!sync && !m_intTxEnabled) { disableInterrupts(); }
m_periodDuration = 0;
m_periodStart = ESP.getCycleCount();
}
void IRAM_ATTR SoftwareSerial::writePeriod(
uint32_t dutyCycle, uint32_t offCycle, bool withStopBit) {
preciseDelay(true);
if (dutyCycle)
{
digitalWrite(m_txPin, HIGH);
m_periodDuration += dutyCycle;
if (offCycle || (withStopBit && !m_invert)) preciseDelay(!withStopBit || m_invert);
}
if (offCycle)
{
digitalWrite(m_txPin, LOW);
m_periodDuration += offCycle;
if (withStopBit && m_invert) preciseDelay(false);
}
}
size_t SoftwareSerial::write(uint8_t byte) {
return write(&byte, 1);
}
size_t SoftwareSerial::write(uint8_t byte, SoftwareSerialParity parity) {
return write(&byte, 1, parity);
}
size_t SoftwareSerial::write(const uint8_t* buffer, size_t size) {
return write(buffer, size, m_parityMode);
}
size_t IRAM_ATTR SoftwareSerial::write(const uint8_t* buffer, size_t size, SoftwareSerialParity parity) {
if (m_rxValid) { rxBits(); }
if (!m_txValid) { return -1; }
if (m_txEnableValid) {
digitalWrite(m_txEnablePin, HIGH);
}
// Stop bit: if inverted, LOW, otherwise HIGH
bool b = !m_invert;
uint32_t dutyCycle = 0;
uint32_t offCycle = 0;
if (!m_intTxEnabled) {
// Disable interrupts in order to get a clean transmit timing
disableInterrupts();
}
const uint32_t dataMask = ((1UL << m_dataBits) - 1);
bool withStopBit = true;
m_periodDuration = 0;
m_periodStart = ESP.getCycleCount();
for (size_t cnt = 0; cnt < size; ++cnt) {
uint8_t byte = pgm_read_byte(buffer + cnt) & dataMask;
// push LSB start-data-parity-stop bit pattern into uint32_t
// Stop bits: HIGH
uint32_t word = ~0UL;
// inverted parity bit, performance tweak for xor all-bits-set word
if (parity && m_parityMode)
{
uint32_t parityBit;
switch (parity)
{
case SWSERIAL_PARITY_EVEN:
// from inverted, so use odd parity
parityBit = byte;
parityBit ^= parityBit >> 4;
parityBit &= 0xf;
parityBit = (0x9669 >> parityBit) & 1;
break;
case SWSERIAL_PARITY_ODD:
// from inverted, so use even parity
parityBit = byte;
parityBit ^= parityBit >> 4;
parityBit &= 0xf;
parityBit = (0x6996 >> parityBit) & 1;
break;
case SWSERIAL_PARITY_MARK:
parityBit = 0;
break;
case SWSERIAL_PARITY_SPACE:
// suppresses warning parityBit uninitialized
default:
parityBit = 1;
break;
}
word ^= parityBit;
}
word <<= m_dataBits;
word |= byte;
// Start bit: LOW
word <<= 1;
if (m_invert) word = ~word;
for (int i = 0; i <= m_pduBits; ++i) {
bool pb = b;
b = word & (1UL << i);
if (!pb && b) {
writePeriod(dutyCycle, offCycle, withStopBit);
withStopBit = false;
dutyCycle = offCycle = 0;
}
if (b) {
dutyCycle += m_bitCycles;
}
else {
offCycle += m_bitCycles;
}
}
withStopBit = true;
}
writePeriod(dutyCycle, offCycle, true);
if (!m_intTxEnabled) {
// restore the interrupt state if applicable
restoreInterrupts();
}
if (m_txEnableValid) {
digitalWrite(m_txEnablePin, LOW);
}
return size;
}
void SoftwareSerial::flush() {
if (!m_rxValid) { return; }
m_buffer->flush();
if (m_parityBuffer)
{
m_parityInPos = m_parityOutPos = 1;
m_parityBuffer->flush();
}
}
bool SoftwareSerial::overflow() {
bool res = m_overflow;
m_overflow = false;
return res;
}
int SoftwareSerial::peek() {
if (!m_rxValid) { return -1; }
if (!m_buffer->available()) {
rxBits();
if (!m_buffer->available()) return -1;
}
auto val = m_buffer->peek();
if (m_parityBuffer) m_lastReadParity = m_parityBuffer->peek() & m_parityOutPos;
return val;
}
void SoftwareSerial::rxBits() {
#ifdef ESP8266
if (m_isrOverflow.load()) {
m_overflow = true;
m_isrOverflow.store(false);
}
#else
if (m_isrOverflow.exchange(false)) {
m_overflow = true;
}
#endif
m_isrBuffer->for_each(m_isrBufferForEachDel);
// A stop bit can go undetected if leading data bits are at same level
// and there was also no next start bit yet, so one word may be pending.
// Check that there was no new ISR data received in the meantime, inserting an
// extraneous stop level bit out of sequence breaks rx.
if (m_rxLastBit < m_pduBits - 1) {
const uint32_t detectionCycles = (m_pduBits - 1 - m_rxLastBit) * m_bitCycles;
if (!m_isrBuffer->available() && ESP.getCycleCount() - m_isrLastCycle > detectionCycles) {
// Produce faux stop bit level, prevents start bit maldetection
// cycle's LSB is repurposed for the level bit
rxBits(((m_isrLastCycle + detectionCycles) | 1) ^ m_invert);
}
}
}
void SoftwareSerial::rxBits(const uint32_t isrCycle) {
const bool level = (m_isrLastCycle & 1) ^ m_invert;
// error introduced by edge value in LSB of isrCycle is negligible
uint32_t cycles = isrCycle - m_isrLastCycle;
m_isrLastCycle = isrCycle;
uint32_t bits = cycles / m_bitCycles;
if (cycles % m_bitCycles > (m_bitCycles >> 1)) ++bits;
while (bits > 0) {
// start bit detection
if (m_rxLastBit >= (m_pduBits - 1)) {
// leading edge of start bit?
if (level) break;
m_rxLastBit = -1;
--bits;
continue;
}
// data bits
if (m_rxLastBit < (m_dataBits - 1)) {
uint8_t dataBits = min(bits, static_cast<uint32_t>(m_dataBits - 1 - m_rxLastBit));
m_rxLastBit += dataBits;
bits -= dataBits;
m_rxCurByte >>= dataBits;
if (level) { m_rxCurByte |= (BYTE_ALL_BITS_SET << (8 - dataBits)); }
continue;
}
// parity bit
if (m_parityMode && m_rxLastBit == (m_dataBits - 1)) {
++m_rxLastBit;
--bits;
m_rxCurParity = level;
continue;
}
// stop bits
// Store the received value in the buffer unless we have an overflow
// if not high stop bit level, discard word
if (bits >= static_cast<uint32_t>(m_pduBits - 1 - m_rxLastBit) && level) {
m_rxCurByte >>= (sizeof(uint8_t) * 8 - m_dataBits);
if (!m_buffer->push(m_rxCurByte)) {
m_overflow = true;
}
else {
if (m_parityBuffer)
{
if (m_rxCurParity) {
m_parityBuffer->pushpeek() |= m_parityInPos;
}
else {
m_parityBuffer->pushpeek() &= ~m_parityInPos;
}
m_parityInPos <<= 1;
if (!m_parityInPos)
{
m_parityBuffer->push();
m_parityInPos = 1;
}
}
}
}
m_rxLastBit = m_pduBits - 1;
// reset to 0 is important for masked bit logic
m_rxCurByte = 0;
m_rxCurParity = false;
break;
}
}
void IRAM_ATTR SoftwareSerial::rxBitISR(SoftwareSerial* self) {
uint32_t curCycle = ESP.getCycleCount();
bool level = digitalRead(self->m_rxPin);
// Store level and cycle in the buffer unless we have an overflow
// cycle's LSB is repurposed for the level bit
if (!self->m_isrBuffer->push((curCycle | 1U) ^ !level)) self->m_isrOverflow.store(true);
}
void IRAM_ATTR SoftwareSerial::rxBitSyncISR(SoftwareSerial* self) {
uint32_t start = ESP.getCycleCount();
uint32_t wait = self->m_bitCycles - 172U;
bool level = self->m_invert;
// Store level and cycle in the buffer unless we have an overflow
// cycle's LSB is repurposed for the level bit
if (!self->m_isrBuffer->push(((start + wait) | 1U) ^ !level)) self->m_isrOverflow.store(true);
for (uint32_t i = 0; i < self->m_pduBits; ++i) {
while (ESP.getCycleCount() - start < wait) {};
wait += self->m_bitCycles;
// Store level and cycle in the buffer unless we have an overflow
// cycle's LSB is repurposed for the level bit
if (digitalRead(self->m_rxPin) != level)
{
if (!self->m_isrBuffer->push(((start + wait) | 1U) ^ level)) self->m_isrOverflow.store(true);
level = !level;
}
}
}
void SoftwareSerial::onReceive(Delegate<void(int available), void*> handler) {
receiveHandler = handler;
}
void SoftwareSerial::perform_work() {
if (!m_rxValid) { return; }
rxBits();
if (receiveHandler) {
int avail = m_buffer->available();
if (avail) { receiveHandler(avail); }
}
}
/*
SoftwareSerial.h
SoftwareSerial.cpp - Implementation of the Arduino software serial for ESP8266/ESP32.
Copyright (c) 2015-2016 Peter Lerup. All rights reserved.
Copyright (c) 2018-2019 Dirk O. Kaar. 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
*/
#ifndef __SoftwareSerial_h
#define __SoftwareSerial_h
#include "circular_queue/circular_queue.h"
#include <Stream.h>
enum SoftwareSerialParity : uint8_t {
SWSERIAL_PARITY_NONE = 000,
SWSERIAL_PARITY_EVEN = 020,
SWSERIAL_PARITY_ODD = 030,
SWSERIAL_PARITY_MARK = 040,
SWSERIAL_PARITY_SPACE = 070,
};
enum SoftwareSerialConfig {
SWSERIAL_5N1 = SWSERIAL_PARITY_NONE,
SWSERIAL_6N1,
SWSERIAL_7N1,
SWSERIAL_8N1,
SWSERIAL_5E1 = SWSERIAL_PARITY_EVEN,
SWSERIAL_6E1,
SWSERIAL_7E1,
SWSERIAL_8E1,
SWSERIAL_5O1 = SWSERIAL_PARITY_ODD,
SWSERIAL_6O1,
SWSERIAL_7O1,
SWSERIAL_8O1,
SWSERIAL_5M1 = SWSERIAL_PARITY_MARK,
SWSERIAL_6M1,
SWSERIAL_7M1,
SWSERIAL_8M1,
SWSERIAL_5S1 = SWSERIAL_PARITY_SPACE,
SWSERIAL_6S1,
SWSERIAL_7S1,
SWSERIAL_8S1,
SWSERIAL_5N2 = 0200 | SWSERIAL_PARITY_NONE,
SWSERIAL_6N2,
SWSERIAL_7N2,
SWSERIAL_8N2,
SWSERIAL_5E2 = 0200 | SWSERIAL_PARITY_EVEN,
SWSERIAL_6E2,
SWSERIAL_7E2,
SWSERIAL_8E2,
SWSERIAL_5O2 = 0200 | SWSERIAL_PARITY_ODD,
SWSERIAL_6O2,
SWSERIAL_7O2,
SWSERIAL_8O2,
SWSERIAL_5M2 = 0200 | SWSERIAL_PARITY_MARK,
SWSERIAL_6M2,
SWSERIAL_7M2,
SWSERIAL_8M2,
SWSERIAL_5S2 = 0200 | SWSERIAL_PARITY_SPACE,
SWSERIAL_6S2,
SWSERIAL_7S2,
SWSERIAL_8S2,
};
/// This class is compatible with the corresponding AVR one, however,
/// the constructor takes no arguments, for compatibility with the
/// HardwareSerial class.
/// Instead, the begin() function handles pin assignments and logic inversion.
/// It also has optional input buffer capacity arguments for byte buffer and ISR bit buffer.
/// Bitrates up to at least 115200 can be used.
class SoftwareSerial : public Stream {
public:
SoftwareSerial();
/// Ctor to set defaults for pins.
/// @param rxPin the GPIO pin used for RX
/// @param txPin -1 for onewire protocol, GPIO pin used for twowire TX
SoftwareSerial(int8_t rxPin, int8_t txPin = -1, bool invert = false);
SoftwareSerial(const SoftwareSerial&) = delete;
SoftwareSerial& operator= (const SoftwareSerial&) = delete;
virtual ~SoftwareSerial();
/// Configure the SoftwareSerial object for use.
/// @param baud the TX/RX bitrate
/// @param config sets databits, parity, and stop bit count
/// @param rxPin -1 or default: either no RX pin, or keeps the rxPin set in the ctor
/// @param txPin -1 or default: either no TX pin (onewire), or keeps the txPin set in the ctor
/// @param invert true: uses invert line level logic
/// @param bufCapacity the capacity for the received bytes buffer
/// @param isrBufCapacity 0: derived from bufCapacity. The capacity of the internal asynchronous
/// bit receive buffer, a suggested size is bufCapacity times the sum of
/// start, data, parity and stop bit count.
void begin(uint32_t baud, SoftwareSerialConfig config,
int8_t rxPin, int8_t txPin, bool invert,
int bufCapacity = 64, int isrBufCapacity = 0);
void begin(uint32_t baud, SoftwareSerialConfig config,
int8_t rxPin, int8_t txPin) {
begin(baud, config, rxPin, txPin, m_invert);
}
void begin(uint32_t baud, SoftwareSerialConfig config,
int8_t rxPin) {
begin(baud, config, rxPin, m_txPin, m_invert);
}
void begin(uint32_t baud, SoftwareSerialConfig config = SWSERIAL_8N1) {
begin(baud, config, m_rxPin, m_txPin, m_invert);
}
uint32_t baudRate();
/// Transmit control pin.
void setTransmitEnablePin(int8_t txEnablePin);
/// Enable (default) or disable interrupts during tx.
void enableIntTx(bool on);
/// Enable (default) or disable internal rx GPIO pullup.
void enableRxGPIOPullup(bool on);
bool overflow();
int available() override;
#if defined(ESP8266)
int availableForWrite() override {
#else
int availableForWrite() {
#endif
if (!m_txValid) return 0;
return 1;
}
int peek() override;
int read() override;
/// @returns The verbatim parity bit associated with the last successful read() or peek() call
bool readParity()
{
return m_lastReadParity;
}
/// @returns The calculated bit for even parity of the parameter byte
static bool parityEven(uint8_t byte) {
byte ^= byte >> 4;
byte &= 0xf;
return (0x6996 >> byte) & 1;
}
/// @returns The calculated bit for odd parity of the parameter byte
static bool parityOdd(uint8_t byte) {
byte ^= byte >> 4;
byte &= 0xf;
return (0x9669 >> byte) & 1;
}
/// The read(buffer, size) functions are non-blocking, the same as readBytes but without timeout
int read(uint8_t* buffer, size_t size)
#if defined(ESP8266)
override
#endif
;
/// The read(buffer, size) functions are non-blocking, the same as readBytes but without timeout
int read(char* buffer, size_t size) {
return read(reinterpret_cast<uint8_t*>(buffer), size);
}
/// @returns The number of bytes read into buffer, up to size. Times out if the limit set through
/// Stream::setTimeout() is reached.
size_t readBytes(uint8_t* buffer, size_t size) override;
/// @returns The number of bytes read into buffer, up to size. Times out if the limit set through
/// Stream::setTimeout() is reached.
size_t readBytes(char* buffer, size_t size) override {
return readBytes(reinterpret_cast<uint8_t*>(buffer), size);
}
void flush() override;
size_t write(uint8_t byte) override;
size_t write(uint8_t byte, SoftwareSerialParity parity);
size_t write(const uint8_t* buffer, size_t size) override;
size_t write(const char* buffer, size_t size) {
return write(reinterpret_cast<const uint8_t*>(buffer), size);
}
size_t write(const uint8_t* buffer, size_t size, SoftwareSerialParity parity);
size_t write(const char* buffer, size_t size, SoftwareSerialParity parity) {
return write(reinterpret_cast<const uint8_t*>(buffer), size, parity);
}
operator bool() const {
return (-1 == m_rxPin || m_rxValid) && (-1 == m_txPin || m_txValid) && !(-1 == m_rxPin && m_oneWire);
}
/// Disable or enable interrupts on the rx pin.
void enableRx(bool on);
/// One wire control.
void enableTx(bool on);
// AVR compatibility methods.
bool listen() { enableRx(true); return true; }
void end();
bool isListening() { return m_rxEnabled; }
bool stopListening() { enableRx(false); return true; }
/// Set an event handler for received data.
void onReceive(Delegate<void(int available), void*> handler);
/// Run the internal processing and event engine. Can be iteratively called
/// from loop, or otherwise scheduled.
void perform_work();
using Print::write;
private:
// If sync is false, it's legal to exceed the deadline, for instance,
// by enabling interrupts.
void preciseDelay(bool sync);
// If withStopBit is set, either cycle contains a stop bit.
// If dutyCycle == 0, the level is not forced to HIGH.
// If offCycle == 0, the level remains unchanged from dutyCycle.
void writePeriod(
uint32_t dutyCycle, uint32_t offCycle, bool withStopBit);
bool isValidGPIOpin(int8_t pin);
bool isValidRxGPIOpin(int8_t pin);
bool isValidTxGPIOpin(int8_t pin);
// result is only defined for a valid Rx GPIO pin
bool hasRxGPIOPullUp(int8_t pin);
// safely set the pin mode for the Rx GPIO pin
void setRxGPIOPullUp();
/* check m_rxValid that calling is safe */
void rxBits();
void rxBits(const uint32_t isrCycle);
static void disableInterrupts();
static void restoreInterrupts();
static void rxBitISR(SoftwareSerial* self);
static void rxBitSyncISR(SoftwareSerial* self);
// Member variables
int8_t m_rxPin = -1;
int8_t m_txPin = -1;
int8_t m_txEnablePin = -1;
uint8_t m_dataBits;
bool m_oneWire;
bool m_rxValid = false;
bool m_rxEnabled = false;
bool m_txValid = false;
bool m_txEnableValid = false;
bool m_invert;
/// PDU bits include data, parity and stop bits; the start bit is not counted.
uint8_t m_pduBits;
bool m_intTxEnabled;
bool m_rxGPIOPullupEnabled;
SoftwareSerialParity m_parityMode;
uint8_t m_stopBits;
bool m_lastReadParity;
bool m_overflow = false;
uint32_t m_bitCycles;
uint8_t m_parityInPos;
uint8_t m_parityOutPos;
int8_t m_rxLastBit; // 0 thru (m_pduBits - m_stopBits - 1): data/parity bits. -1: start bit. (m_pduBits - 1): stop bit.
uint8_t m_rxCurByte = 0;
std::unique_ptr<circular_queue<uint8_t> > m_buffer;
std::unique_ptr<circular_queue<uint8_t> > m_parityBuffer;
uint32_t m_periodStart;
uint32_t m_periodDuration;
#ifndef ESP32
static uint32_t m_savedPS;
#else
static portMUX_TYPE m_interruptsMux;
#endif
// the ISR stores the relative bit times in the buffer. The inversion corrected level is used as sign bit (2's complement):
// 1 = positive including 0, 0 = negative.
std::unique_ptr<circular_queue<uint32_t, SoftwareSerial*> > m_isrBuffer;
const Delegate<void(uint32_t&&), SoftwareSerial*> m_isrBufferForEachDel = { [](SoftwareSerial* self, uint32_t&& isrCycle) { self->rxBits(isrCycle); }, this };
std::atomic<bool> m_isrOverflow;
uint32_t m_isrLastCycle;
bool m_rxCurParity = false;
Delegate<void(int available), void*> receiveHandler;
};
#endif // __SoftwareSerial_h
/*
MultiDelegate.h - A queue or event multiplexer based on the efficient Delegate
class
Copyright (c) 2019-2020 Dirk O. Kaar. 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
*/
#ifndef __MULTIDELEGATE_H
#define __MULTIDELEGATE_H
#include <iterator>
#if defined(ESP8266) || defined(ESP32) || !defined(ARDUINO)
#include <atomic>
#else
#include "circular_queue/ghostl.h"
#endif
#if defined(ESP8266)
#include <interrupts.h>
using esp8266::InterruptLock;
#elif defined(ARDUINO)
class InterruptLock {
public:
InterruptLock() {
noInterrupts();
}
~InterruptLock() {
interrupts();
}
};
#else
#include <mutex>
#endif
namespace
{
template< typename Delegate, typename R, bool ISQUEUE = false, typename... P>
struct CallP
{
static R execute(Delegate& del, P... args)
{
return del(std::forward<P...>(args...));
}
};
template< typename Delegate, bool ISQUEUE, typename... P>
struct CallP<Delegate, void, ISQUEUE, P...>
{
static bool execute(Delegate& del, P... args)
{
del(std::forward<P...>(args...));
return true;
}
};
template< typename Delegate, typename R, bool ISQUEUE = false>
struct Call
{
static R execute(Delegate& del)
{
return del();
}
};
template< typename Delegate, bool ISQUEUE>
struct Call<Delegate, void, ISQUEUE>
{
static bool execute(Delegate& del)
{
del();
return true;
}
};
}
namespace delegate
{
namespace detail
{
template< typename Delegate, typename R, bool ISQUEUE = false, size_t QUEUE_CAPACITY = 32, typename... P>
class MultiDelegatePImpl
{
public:
MultiDelegatePImpl() = default;
~MultiDelegatePImpl()
{
*this = nullptr;
}
MultiDelegatePImpl(const MultiDelegatePImpl&) = delete;
MultiDelegatePImpl& operator=(const MultiDelegatePImpl&) = delete;
MultiDelegatePImpl(MultiDelegatePImpl&& md)
{
first = md.first;
last = md.last;
unused = md.unused;
nodeCount = md.nodeCount;
md.first = nullptr;
md.last = nullptr;
md.unused = nullptr;
md.nodeCount = 0;
}
MultiDelegatePImpl(const Delegate& del)
{
add(del);
}
MultiDelegatePImpl(Delegate&& del)
{
add(std::move(del));
}
MultiDelegatePImpl& operator=(MultiDelegatePImpl&& md)
{
first = md.first;
last = md.last;
unused = md.unused;
nodeCount = md.nodeCount;
md.first = nullptr;
md.last = nullptr;
md.unused = nullptr;
md.nodeCount = 0;
return *this;
}
MultiDelegatePImpl& operator=(std::nullptr_t)
{
if (last)
last->mNext = unused;
if (first)
unused = first;
while (unused)
{
auto to_delete = unused;
unused = unused->mNext;
delete(to_delete);
}
return *this;
}
MultiDelegatePImpl& operator+=(const Delegate& del)
{
add(del);
return *this;
}
MultiDelegatePImpl& operator+=(Delegate&& del)
{
add(std::move(del));
return *this;
}
protected:
struct Node_t
{
~Node_t()
{
mDelegate = nullptr; // special overload in Delegate
}
Node_t* mNext = nullptr;
Delegate mDelegate;
};
Node_t* first = nullptr;
Node_t* last = nullptr;
Node_t* unused = nullptr;
size_t nodeCount = 0;
// Returns a pointer to an unused Node_t,
// or if none are available allocates a new one,
// or nullptr if limit is reached
Node_t* IRAM_ATTR get_node_unsafe()
{
Node_t* result = nullptr;
// try to get an item from unused items list
if (unused)
{
result = unused;
unused = unused->mNext;
}
// if no unused items, and count not too high, allocate a new one
else if (nodeCount < QUEUE_CAPACITY)
{
#if defined(ESP8266) || defined(ESP32)
result = new (std::nothrow) Node_t;
#else
result = new Node_t;
#endif
if (result)
++nodeCount;
}
return result;
}
void recycle_node_unsafe(Node_t* node)
{
node->mDelegate = nullptr; // special overload in Delegate
node->mNext = unused;
unused = node;
}
#ifndef ARDUINO
std::mutex mutex_unused;
#endif
public:
class iterator : public std::iterator<std::forward_iterator_tag, Delegate>
{
public:
Node_t* current = nullptr;
Node_t* prev = nullptr;
const Node_t* stop = nullptr;
iterator(MultiDelegatePImpl& md) : current(md.first), stop(md.last) {}
iterator() = default;
iterator(const iterator&) = default;
iterator& operator=(const iterator&) = default;
iterator& operator=(iterator&&) = default;
operator bool() const
{
return current && stop;
}
bool operator==(const iterator& rhs) const
{
return current == rhs.current;
}
bool operator!=(const iterator& rhs) const
{
return !operator==(rhs);
}
Delegate& operator*() const
{
return current->mDelegate;
}
Delegate* operator->() const
{
return &current->mDelegate;
}
iterator& operator++() // prefix
{
if (current && stop != current)
{
prev = current;
current = current->mNext;
}
else
current = nullptr; // end
return *this;
}
iterator& operator++(int) // postfix
{
iterator tmp(*this);
operator++();
return tmp;
}
};
iterator begin()
{
return iterator(*this);
}
iterator end() const
{
return iterator();
}
const Delegate* IRAM_ATTR add(const Delegate& del)
{
return add(Delegate(del));
}
const Delegate* IRAM_ATTR add(Delegate&& del)
{
if (!del)
return nullptr;
#ifdef ARDUINO
InterruptLock lockAllInterruptsInThisScope;
#else
std::lock_guard<std::mutex> lock(mutex_unused);
#endif
Node_t* item = ISQUEUE ? get_node_unsafe() :
#if defined(ESP8266) || defined(ESP32)
new (std::nothrow) Node_t;
#else
new Node_t;
#endif
if (!item)
return nullptr;
item->mDelegate = std::move(del);
item->mNext = nullptr;
if (last)
last->mNext = item;
else
first = item;
last = item;
return &item->mDelegate;
}
iterator erase(iterator it)
{
if (!it)
return end();
#ifdef ARDUINO
InterruptLock lockAllInterruptsInThisScope;
#else
std::lock_guard<std::mutex> lock(mutex_unused);
#endif
auto to_recycle = it.current;
if (last == it.current)
last = it.prev;
it.current = it.current->mNext;
if (it.prev)
{
it.prev->mNext = it.current;
}
else
{
first = it.current;
}
if (ISQUEUE)
recycle_node_unsafe(to_recycle);
else
delete to_recycle;
return it;
}
bool erase(const Delegate* const del)
{
auto it = begin();
while (it)
{
if (del == &(*it))
{
erase(it);
return true;
}
++it;
}
return false;
}
operator bool() const
{
return first;
}
R operator()(P... args)
{
auto it = begin();
if (!it)
return {};
static std::atomic<bool> fence(false);
// prevent recursive calls
#if defined(ARDUINO) && !defined(ESP32)
if (fence.load()) return {};
fence.store(true);
#else
if (fence.exchange(true)) return {};
#endif
R result;
do
{
result = CallP<Delegate, R, ISQUEUE, P...>::execute(*it, args...);
if (result && ISQUEUE)
it = erase(it);
else
++it;
#if defined(ESP8266) || defined(ESP32)
// running callbacks might last too long for watchdog etc.
optimistic_yield(10000);
#endif
} while (it);
fence.store(false);
return result;
}
};
template< typename Delegate, typename R = void, bool ISQUEUE = false, size_t QUEUE_CAPACITY = 32>
class MultiDelegateImpl : public MultiDelegatePImpl<Delegate, R, ISQUEUE, QUEUE_CAPACITY>
{
public:
using MultiDelegatePImpl<Delegate, R, ISQUEUE, QUEUE_CAPACITY>::MultiDelegatePImpl;
R operator()()
{
auto it = this->begin();
if (!it)
return {};
static std::atomic<bool> fence(false);
// prevent recursive calls
#if defined(ARDUINO) && !defined(ESP32)
if (fence.load()) return {};
fence.store(true);
#else
if (fence.exchange(true)) return {};
#endif
R result;
do
{
result = Call<Delegate, R, ISQUEUE>::execute(*it);
if (result && ISQUEUE)
it = this->erase(it);
else
++it;
#if defined(ESP8266) || defined(ESP32)
// running callbacks might last too long for watchdog etc.
optimistic_yield(10000);
#endif
} while (it);
fence.store(false);
return result;
}
};
template< typename Delegate, typename R, bool ISQUEUE, size_t QUEUE_CAPACITY, typename... P> class MultiDelegate;
template< typename Delegate, typename R, bool ISQUEUE, size_t QUEUE_CAPACITY, typename... P>
class MultiDelegate<Delegate, R(P...), ISQUEUE, QUEUE_CAPACITY> : public MultiDelegatePImpl<Delegate, R, ISQUEUE, QUEUE_CAPACITY, P...>
{
public:
using MultiDelegatePImpl<Delegate, R, ISQUEUE, QUEUE_CAPACITY, P...>::MultiDelegatePImpl;
};
template< typename Delegate, typename R, bool ISQUEUE, size_t QUEUE_CAPACITY>
class MultiDelegate<Delegate, R(), ISQUEUE, QUEUE_CAPACITY> : public MultiDelegateImpl<Delegate, R, ISQUEUE, QUEUE_CAPACITY>
{
public:
using MultiDelegateImpl<Delegate, R, ISQUEUE, QUEUE_CAPACITY>::MultiDelegateImpl;
};
template< typename Delegate, bool ISQUEUE, size_t QUEUE_CAPACITY, typename... P>
class MultiDelegate<Delegate, void(P...), ISQUEUE, QUEUE_CAPACITY> : public MultiDelegatePImpl<Delegate, void, ISQUEUE, QUEUE_CAPACITY, P...>
{
public:
using MultiDelegatePImpl<Delegate, void, ISQUEUE, QUEUE_CAPACITY, P...>::MultiDelegatePImpl;
void operator()(P... args)
{
auto it = this->begin();
if (!it)
return;
static std::atomic<bool> fence(false);
// prevent recursive calls
#if defined(ARDUINO) && !defined(ESP32)
if (fence.load()) return;
fence.store(true);
#else
if (fence.exchange(true)) return;
#endif
do
{
CallP<Delegate, void, ISQUEUE, P...>::execute(*it, args...);
if (ISQUEUE)
it = this->erase(it);
else
++it;
#if defined(ESP8266) || defined(ESP32)
// running callbacks might last too long for watchdog etc.
optimistic_yield(10000);
#endif
} while (it);
fence.store(false);
}
};
template< typename Delegate, bool ISQUEUE, size_t QUEUE_CAPACITY>
class MultiDelegate<Delegate, void(), ISQUEUE, QUEUE_CAPACITY> : public MultiDelegateImpl<Delegate, void, ISQUEUE, QUEUE_CAPACITY>
{
public:
using MultiDelegateImpl<Delegate, void, ISQUEUE, QUEUE_CAPACITY>::MultiDelegateImpl;
void operator()()
{
auto it = this->begin();
if (!it)
return;
static std::atomic<bool> fence(false);
// prevent recursive calls
#if defined(ARDUINO) && !defined(ESP32)
if (fence.load()) return;
fence.store(true);
#else
if (fence.exchange(true)) return;
#endif
do
{
Call<Delegate, void, ISQUEUE>::execute(*it);
if (ISQUEUE)
it = this->erase(it);
else
++it;
#if defined(ESP8266) || defined(ESP32)
// running callbacks might last too long for watchdog etc.
optimistic_yield(10000);
#endif
} while (it);
fence.store(false);
}
};
}
}
/**
The MultiDelegate class template can be specialized to either a queue or an event multiplexer.
It is designed to be used with Delegate, the efficient runtime wrapper for C function ptr and C++ std::function.
@tparam Delegate specifies the concrete type that MultiDelegate bases the queue or event multiplexer on.
@tparam ISQUEUE modifies the generated MultiDelegate class in subtle ways. In queue mode (ISQUEUE == true),
the value of QUEUE_CAPACITY enforces the maximum number of simultaneous items the queue can contain.
This is exploited to minimize the use of new and delete by reusing already allocated items, thus
reducing heap fragmentation. In event multiplexer mode (ISQUEUE = false), new and delete are
used for allocation of the event handler items.
If the result type of the function call operator of Delegate is void, calling a MultiDelegate queue
removes each item after calling it; a Multidelegate event multiplexer keeps event handlers until
explicitly removed.
If the result type of the function call operator of Delegate is non-void, in a MultiDelegate queue
the type-conversion to bool of that result determines if the item is immediately removed or kept
after each call: if true is returned, the item is removed. A Multidelegate event multiplexer keeps event
handlers until they are explicitly removed.
@tparam QUEUE_CAPACITY is only used if ISQUEUE == true. Then, it sets the maximum capacity that the queue dynamically
allocates from the heap. Unused items are not returned to the heap, but are managed by the MultiDelegate
instance during its own lifetime for efficiency.
*/
template< typename Delegate, bool ISQUEUE = false, size_t QUEUE_CAPACITY = 32>
class MultiDelegate : public delegate::detail::MultiDelegate<Delegate, typename Delegate::target_type, ISQUEUE, QUEUE_CAPACITY>
{
public:
using delegate::detail::MultiDelegate<Delegate, typename Delegate::target_type, ISQUEUE, QUEUE_CAPACITY>::MultiDelegate;
};
#endif // __MULTIDELEGATE_H
/*
ghostl.h - Implementation of a bare-bones, mostly no-op, C++ STL shell
that allows building some Arduino ESP8266/ESP32
libraries on Aruduino AVR.
Copyright (c) 2019 Dirk O. Kaar. 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
*/
#ifndef __ghostl_h
#define __ghostl_h
#if defined(ARDUINO_ARCH_SAMD)
#include <atomic>
#endif
using size_t = decltype(sizeof(char));
namespace std
{
#if !defined(ARDUINO_ARCH_SAMD)
typedef enum memory_order {
memory_order_relaxed,
memory_order_acquire,
memory_order_release,
memory_order_seq_cst
} memory_order;
template< typename T > class atomic {
private:
T value;
public:
atomic() {}
atomic(T desired) { value = desired; }
void store(T desired, std::memory_order = std::memory_order_seq_cst) volatile noexcept { value = desired; }
T load(std::memory_order = std::memory_order_seq_cst) const volatile noexcept { return value; }
};
inline void atomic_thread_fence(std::memory_order order) noexcept {}
template< typename T > T&& move(T& t) noexcept { return static_cast<T&&>(t); }
#endif
template< typename T, size_t long N > struct array
{
T _M_elems[N];
decltype(sizeof(0)) size() const { return N; }
T& operator[](decltype(sizeof(0)) i) { return _M_elems[i]; }
const T& operator[](decltype(sizeof(0)) i) const { return _M_elems[i]; }
};
template< typename T > class unique_ptr
{
public:
using pointer = T*;
unique_ptr() noexcept : ptr(nullptr) {}
unique_ptr(pointer p) : ptr(p) {}
pointer operator->() const noexcept { return ptr; }
T& operator[](decltype(sizeof(0)) i) const { return ptr[i]; }
void reset(pointer p = pointer()) noexcept
{
delete ptr;
ptr = p;
}
T& operator*() const { return *ptr; }
private:
pointer ptr;
};
template< typename T > using function = T*;
using nullptr_t = decltype(nullptr);
template<typename T>
struct identity {
typedef T type;
};
template <typename T>
inline T&& forward(typename identity<T>::type& t) noexcept
{
return static_cast<typename identity<T>::type&&>(t);
}
}
#endif // __ghostl_h
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