wled_serial.cpp

#include "wled.h"

/*
 * Adalight and TPM2 handler
 */

#define SERIAL_MAXTIME_MILLIS 100 // to avoid blocking other activities, do not spend more than 100ms with continouus reading
// at 115200 baud, 100ms is enough to send/receive 1280 chars

enum class AdaState {
  Header_A,
  Header_d,
  Header_a,
  Header_CountHi,
  Header_CountLo,
  Header_CountCheck,
  Data_Red,
  Data_Green,
  Data_Blue,
  TPM2_Header_Type,
  TPM2_Header_CountHi,
  TPM2_Header_CountLo,
};

uint16_t currentBaud = 1152; //default baudrate 115200 (divided by 100)
bool continuousSendLED = false;
uint32_t lastUpdate = 0;

void updateBaudRate(uint32_t rate){
  uint16_t rate100 = rate/100;
  if (rate100 == currentBaud || rate100 < 96) return;
  currentBaud = rate100;

  if (!pinManager.isPinAllocated(hardwareTX) || pinManager.getPinOwner(hardwareTX) == PinOwner::DebugOut){
    if (Serial) { Serial.print(F("Baud is now ")); Serial.println(rate); }
  }

  if (Serial) Serial.flush();
  Serial.begin(rate);
}

// RGB LED data return as JSON array. Slow, but easy to use on the other end.
void sendJSON(){
  if (!pinManager.isPinAllocated(hardwareTX) || pinManager.getPinOwner(hardwareTX) == PinOwner::DebugOut) {
    uint16_t used = strip.getLengthTotal();
    Serial.write('[');
    for (uint16_t i=0; i<used; i++) {
      Serial.print(strip.getPixelColor(i));
      if (i != used-1) Serial.write(',');
    }
    Serial.println("]");
  }
}

// RGB LED data returned as bytes in TPM2 format. Faster, and slightly less easy to use on the other end.
void sendBytes(){
  if (!pinManager.isPinAllocated(hardwareTX) || pinManager.getPinOwner(hardwareTX) == PinOwner::DebugOut) {
    Serial.write(0xC9); Serial.write(0xDA);
    uint16_t used = strip.getLengthTotal();
    uint16_t len = used*3;
    Serial.write(highByte(len));
    Serial.write(lowByte(len));
    for (uint16_t i=0; i < used; i++) {
      uint32_t c = strip.getPixelColor(i);
      Serial.write(qadd8(W(c), R(c))); //R, add white channel to RGB channels as a simple RGBW -> RGB map
      Serial.write(qadd8(W(c), G(c))); //G
      Serial.write(qadd8(W(c), B(c))); //B
    }
    Serial.write(0x36); Serial.write('\n');
  }
}

bool canUseSerial(void) {   // WLEDMM returns true if Serial can be used for debug output (i.e. not configured for other purpose)
  #if defined(CONFIG_IDF_TARGET_ESP32C3) && ARDUINO_USB_CDC_ON_BOOT && !defined(WLED_DEBUG_HOST)
  //  on -C3, USB CDC blocks if disconnected! so check if Serial is active before printing to it.
  if (!Serial) return false;
  #endif
  if (pinManager.isPinAllocated(hardwareTX) && (pinManager.getPinOwner(hardwareTX) != PinOwner::DebugOut)) 
    return false;  // TX allocated to LEDs or other functions
  if ((realtimeMode == REALTIME_MODE_GENERIC) ||  (realtimeMode == REALTIME_MODE_ADALIGHT) || (realtimeMode == REALTIME_MODE_TPM2NET)) 
    return false;  // Serial in use for adaLight or other serial communication
  //if ((improvActive == 1) || (improvActive == 2)) return false; // don't interfere when IMPROV communication is ongoing
  if (improvActive > 0) return false;              // don't interfere when IMPROV communication is ongoing
  if (continuousSendLED == true) return false;     // Continuous Serial Streaming

  return true;
} // WLEDMM end

void handleSerial()
{
  if (pinManager.isPinAllocated(hardwareRX)) return;
  if (!Serial) return;              // arduino docs: `if (Serial)` indicates whether or not the USB CDC serial connection is open. For all non-USB CDC ports, this will always return true
  if (((pinManager.isPinAllocated(hardwareTX)) && (pinManager.getPinOwner(hardwareTX) != PinOwner::DebugOut))) return; // WLEDMM serial TX is necessary for adalight / TPM2

  #ifdef WLED_ENABLE_ADALIGHT
  static auto state = AdaState::Header_A;
  static uint16_t count = 0;
  static uint16_t pixel = 0;
  static byte check = 0x00;
  static byte red   = 0x00;
  static byte green = 0x00;

  unsigned long startTime = millis();
  while ((Serial.available() > 0) && (millis() - startTime < SERIAL_MAXTIME_MILLIS))
  {
    yield();
    byte next = Serial.peek();
    switch (state) {
      case AdaState::Header_A:
        if (next == 'A') state = AdaState::Header_d;
        else if (next == 0xC9) { //TPM2 start byte
          state = AdaState::TPM2_Header_Type;
        }
        else if (next == 'I') {
          handleImprovPacket();
          return;
        } else if (next == 'v') {
          Serial.print("WLED"); Serial.write(' '); Serial.println(VERSION);

        } else if (next == 'X') {
          forceReconnect = true; // WLEDMM - force reconnect via Serial
        } else if (next == 0xB0) {updateBaudRate( 115200);
        } else if (next == 0xB1) {updateBaudRate( 230400);
        } else if (next == 0xB2) {updateBaudRate( 460800);
        } else if (next == 0xB3) {updateBaudRate( 500000);
        } else if (next == 0xB4) {updateBaudRate( 576000);
        } else if (next == 0xB5) {updateBaudRate( 921600);
        } else if (next == 0xB6) {updateBaudRate(1000000);
        } else if (next == 0xB7) {updateBaudRate(1500000);

        } else if (next == 'l') {sendJSON(); // Send LED data as JSON Array
        } else if (next == 'L') {sendBytes(); // Send LED data as TPM2 Data Packet

        } else if (next == 'o') {continuousSendLED = false; // Disable Continuous Serial Streaming
        } else if (next == 'O') {continuousSendLED = true; // Enable Continuous Serial Streaming

        } else if (next == '{') { //JSON API
          bool verboseResponse = false;
          if (!requestJSONBufferLock(16)) return;
          Serial.setTimeout(100);
          DeserializationError error = deserializeJson(doc, Serial);
          if (error) {
            releaseJSONBufferLock();
            return;
          }
          verboseResponse = deserializeState(doc.as<JsonObject>());
          //only send response if TX pin is unused for other purposes
          if (verboseResponse && (!pinManager.isPinAllocated(hardwareTX) || pinManager.getPinOwner(hardwareTX) == PinOwner::DebugOut)) {
            doc.clear();
            JsonObject state = doc.createNestedObject("state");
            serializeState(state);
            JsonObject info  = doc.createNestedObject("info");
            serializeInfo(info);

            serializeJson(doc, Serial);
            Serial.println();
          }
          releaseJSONBufferLock();
        }
        break;
      case AdaState::Header_d:
        if (next == 'd') state = AdaState::Header_a;
        else             state = AdaState::Header_A;
        break;
      case AdaState::Header_a:
        if (next == 'a') state = AdaState::Header_CountHi;
        else             state = AdaState::Header_A;
        break;
      case AdaState::Header_CountHi:
        pixel = 0;
        count = next * 0x100;
        check = next;
        state = AdaState::Header_CountLo;
        break;
      case AdaState::Header_CountLo:
        count += next + 1;
        check = check ^ next ^ 0x55;
        state = AdaState::Header_CountCheck;
        break;
      case AdaState::Header_CountCheck:
        if (check == next) state = AdaState::Data_Red;
        else               state = AdaState::Header_A;
        break;
      case AdaState::TPM2_Header_Type:
        state = AdaState::Header_A; //(unsupported) TPM2 command or invalid type
        if (next == 0xDA) state = AdaState::TPM2_Header_CountHi; //TPM2 data
        else if (next == 0xAA) Serial.write(0xAC); //TPM2 ping
        break;
      case AdaState::TPM2_Header_CountHi:
        pixel = 0;
        count = (next * 0x100) /3;
        state = AdaState::TPM2_Header_CountLo;
        break;
      case AdaState::TPM2_Header_CountLo:
        count += next /3;
        state = AdaState::Data_Red;
        break;
      case AdaState::Data_Red:
        red   = next;
        state = AdaState::Data_Green;
        break;
      case AdaState::Data_Green:
        green = next;
        state = AdaState::Data_Blue;
        break;
      case AdaState::Data_Blue:
        byte blue  = next;
        if (!realtimeOverride) setRealtimePixel(pixel++, red, green, blue, 0);
        if (--count > 0) state = AdaState::Data_Red;
        else {
          realtimeLock(realtimeTimeoutMs, REALTIME_MODE_ADALIGHT);

          if (!realtimeOverride) strip.show();
          state = AdaState::Header_A;
        }
        break;
    }

    // All other received bytes will disable Continuous Serial Streaming
    if (continuousSendLED && next != 'O'){
      continuousSendLED = false;
      }

    Serial.read(); //discard the byte
  }
  //#ifdef WLED_DEBUG
    if ((millis() - startTime) > SERIAL_MAXTIME_MILLIS) { USER_PRINTLN(F("handleSerial(): need a break after >100ms of activity.")); }
  //#endif
  #endif

  // If Continuous Serial Streaming is enabled, send new LED data as bytes
  if (continuousSendLED && (lastUpdate != strip.getLastShow())){
    sendBytes();
    lastUpdate = strip.getLastShow();
  }
}