Senseair S8 also works on ESP8266 now

ampel-firmware/co2_sensor.cpp

@@ -18,17 +18,19 @@ namespace config {
 }
 
 #if defined(ESP8266)
-// For ESP8266 : RX on GPIO3, TX on GPIO1
-//TODO: Really not sure it works
-#   define S8_UART_PORT  0
+#  include "src/lib/EspSoftwareSerial/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);
 #endif
 #if defined(ESP32)
-// For ESP32 : RX on GPIO17, TX on GPIO16
-#   define S8_UART_PORT  2
+// GPIO16 connected to S8 Tx pin.
+// GPIO17 connected to S8 Rx pin.
+#  define S8_UART_PORT  2
+HardwareSerial S8_serial(S8_UART_PORT);
 #endif
 
 namespace sensor {
-  HardwareSerial S8_serial(S8_UART_PORT);
   S8_UART *sensor_S8;
   S8_sensor s8;
   uint16_t co2 = 0;

ampel-firmware/src/lib/EspSoftwareSerial/README.md

+# 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
+```

ampel-firmware/src/lib/EspSoftwareSerial/SoftwareSerial.cpp

+/*
+
+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;