esp8266_artnet_dmx512.ino

/*
   This sketch receives Art-Net data of one DMX universes over WiFi
   and sends it to a MAX485 module as an interface between wireless
   Art-Net and wired DMX512.

   This firmware can either use the UART (aka Serial) interface to
   the MAX485 module, or the I2S interface. Note that the wiring
   depends on whether you use UART or I2S.

   See https://robertoostenveld.nl/art-net-to-dmx512-with-esp8266/
   and comments to that blog post.

   See https://github.com/robertoostenveld/esp8266_artnet_dmx512
*/

#include <Arduino.h>
#include <ESP8266WiFi.h>         // https://github.com/esp8266/Arduino
#include <ESP8266WebServer.h>
#include <ESP8266mDNS.h>
#include <WiFiManager.h>         // https://github.com/tzapu/WiFiManager
#include <ArtnetWifi.h>          // https://github.com/rstephan/ArtnetWifi
#include <ArduinoJson.h>

#include "rgb_led.h"
#include "webinterface.h"

#define MIN(x,y) (x<y ? x : y)
#define MAX(x,y) (x>y ? x : y)

/*********************************************************************************/

// Uncomment to send DMX data using the microcontroller's builtin UART.
// This is the original way this sketch used to work and expects the max485 level
// shifter to be connected to the pin that corresponds to Serial1.
// On a Wemos D1 this is pin D4 aka TX1.
#define ENABLE_UART

// Uncomment to send DMX data via I2S instead of UART.
// I2S allows for better control of number of stop bits and DMX timing to meet the
// requirements of sloppy devices. Moreover using DMA reduces strain of the CPU and avoids
// issues with background activity such as handling WiFi, interrupts etc.
// However - because of the extra timing/pauses for sloppy device, sending DMX over I2S
// will cause throughput to drop from approx 40 packets/s to around 30.
// On a Wemos D1 I2S is available on pin RX0.
#define ENABLE_I2S

// Enable kind of unit test for new I2S code moving around a knowingly picky device
// (china brand moving head with timing issues)
//#define WITH_TEST_CODE

// Comment in to enable standalone mode. This means that the setup function won't
// block until the device was configured to connect to a Wifi network but will start
// to receive Artnet data right away on the access point network that the WifiManager
// created for this purpose. You can then simply ignore the configuration attempt and
// use the device without a local Wifi network or choose to connect one later.
// Consider setting also a password in standalone mode, otherwise someone else might
// configure your device to connect to a random Wifi.
//#define ENABLE_STANDALONE
//#define STANDALONE_PASSWORD "wifisecret"

// Enable OTA (over the air programming in the Arduino GUI, not via the web server)
//#define ENABLE_ARDUINO_OTA
//#define ARDUINO_OTA_PASSWORD "otasecret"

// Enable the web interface that allows to configure the ArtNet universe, the number
// of channels, etcetera
#define ENABLE_WEBINTERFACE

// Enable multicast DNS, which resolves hostnames to IP addresses within small networks
// that do not include a local name server
#define ENABLE_MDNS

/*********************************************************************************/

#ifdef ENABLE_UART
#include "c_types.h"
#include "eagle_soc.h"
#include "uart_register.h"
// there are two different implementations for the break, one using serial, the other using low-level timings; both should work
#define USE_SERIAL_BREAK
/* UART for DMX output */
#define SEROUT_UART 1
/* DMX minimum timings per E1.11 */
#define DMX_BREAK 92
#define DMX_MAB 12
#endif // ENABLE_UART

/*********************************************************************************/

#ifdef ENABLE_I2S
#include <I2S.h>
#include <i2s_reg.h>
#define I2S_PIN 3
#define DMX_CHANNELS 512

// See comments below
//#define I2S_SUPER_SAFE

#ifdef I2S_SUPER_SAFE
// Below timings are based on measures taken with a commercial DMX512 controller.
// They differ substentially from the offcial DMX standard ... breaks are longer, more
// stop bits. Apparently to please some picky devices out there that cannot handle
// DMX data quickly enough.
// Using these parameters results in a throughput of approx. 29.7 packets/s (with 512 DMX channels)
typedef struct {
  uint16_t mark_before_break[10]; // 10 * 16 bits * 4 us -> 640 us
  uint16_t space_for_break[2]; // 2 * 16 bits * 4 us -> 128 us
  uint16_t mark_after_break; // 13 MSB low bits * 4 us adds 52 us to space_for_break -> 180 us
  // each "byte" (actually a word) consists of:
  // 8 bits payload + 7 stop bits (high) + 1 start (low) for the next byte
  uint16_t dmx_bytes[DMX_CHANNELS + 1];
} i2s_packet;

#else
// This configuration sets way shorter MBB and SFB but still adds lots of extra stop bits.
// At least for my devices this still works and increases thrughput slightly to 30.3  packets/s.
typedef struct {
  uint16_t mark_before_break[1]; // 1 * 16 bits * 4 us -> 64 us
  uint16_t space_for_break[1]; // 1 * 16 bits * 4 us -> 64 us
  uint16_t mark_after_break; // 13 MSB low bits * 4 us adds 52 us to space_for_break -> 116 us
  // each "byte" (actually a word) consists of:
  // 8 bits payload + 7 stop bits (high) + 1 start (low) for the next byte
  uint16_t dmx_bytes[DMX_CHANNELS + 1];
} i2s_packet;
#endif // I2S_SUPER_SAFE

#endif // ENABLE_I2S

/*********************************************************************************/

const char* host = "ARTNET";
const char* version = __DATE__ " / " __TIME__;

Config config;
ESP8266WebServer server(80);
ArtnetWifi artnet;
WiFiManager wifiManager;

// keep track of the timing of the function calls
long tic_loop = 0, tic_fps = 0, tic_packet = 0, tic_web = 0;
unsigned long packetCounter = 0, frameCounter = 0, last_packet_received = 0;
float fps = 0;

// Global buffer with one Artnet universe
struct  {
  uint16_t universe;
  uint16_t length;
  uint8_t sequence;
#ifdef ENABLE_UART
  uint8_t uart_data[512];
#endif
#ifdef ENABLE_I2S
  i2s_packet i2s_data;
  uint16_t i2s_length;
#endif
} global;

#ifdef ENABLE_ARDUINO_OTA
#include <ArduinoOTA.h>
// Keep track whether OTA was started
bool arduinoOtaStarted = false;
unsigned int last_ota_progress = 0;
#endif

#ifdef ENABLE_UART
long tic_uart = 0;
unsigned long uartCounter;
#endif

#ifdef ENABLE_I2S
long tic_i2s = 0;
unsigned long i2sCounter;
#endif

/*********************************************************************************/

// This will be called for each UDP packet that is received
void onDmxPacket(uint16_t universe, uint16_t length, uint8_t sequence, uint8_t * data) {

  unsigned long now = millis();
  if (now - last_packet_received > 1000) {
    Serial.print("Received DMX data\n");
  }
  last_packet_received = now;

  // print some feedback once per second
  if ((millis() - tic_fps) > 1000 && frameCounter > 100) {
    Serial.print("packetCounter = ");
    Serial.print(packetCounter++);
    // don't estimate the FPS too frequently
    fps = 1000 * frameCounter / (millis() - tic_fps);
    tic_fps = last_packet_received;
    frameCounter = 0;
    Serial.print(", FPS = ");             Serial.print(fps);
    // print out also some diagnostic info
    Serial.print(", length = ");          Serial.print(length);
    Serial.print(", sequence = ");        Serial.print(sequence);
    Serial.print(", universe = ");        Serial.print(universe);
    Serial.print(", config.universe = "); Serial.print(universe);
    Serial.println();
  }

  if (universe == config.universe) {
    // copy the data from the UDP packet
    global.universe = universe;
    global.sequence = sequence;

#ifdef ENABLE_I2S
    // TODO optimize i2s such that it can send less than 512 bytes if not required (length<512)
    // we are sending I2S _frames_ (not bytes) and every frame consists of 2 words,
    // so we must ensure an even number of DMX values where every walue is a word

    /* do not activate before thoroughly tested with arbitrary DMX sizes
       int even_length = 2 * (length + 1) / 2;
       if (even_length > DMX_CHANNELS) {
       even_length = DMX_CHANNELS;
       }
       int skipped_bytes = 2 * (DMX_CHANNELS - even_length); // divisible by 4
       global.i2s_length = sizeof(global.i2s_data) - skipped_bytes;
       Serial.printf("length=%d, even_length=%d, skipped_bytes=%d, i2s_length=%d, sizeof(i2s_data)=%d\n",
                  length, even_length, skipped_bytes, global.i2s_length, sizeof(global.i2s_data));
    */

    for (int i = 0; i < DMX_CHANNELS; i++) {
      uint16_t hi = i < length ? flipByte(data[i]) : 0;
      // Add stop bits and start bit of next byte unless there is no next byte.
      uint16_t lo = i == DMX_CHANNELS - 1 ? 0b0000000011111111 : 0b0000000011111110;
      // leave the start-byte (index 0) untouched => +1:
      global.i2s_data.dmx_bytes[i + 1] = (hi << 8) | lo;
    }
#endif

#ifdef ENABLE_UART
    if (length <= 512)
      global.length = length;
    for (int i = 0; i < global.length; i++) {
      global.uart_data[i] = data[i];
    }
#endif
  }
} // onDmxpacket

/*********************************************************************************/

void setup() {

  // Serial0 is for debugging purposes
  Serial.begin(115200);
  while (!Serial) {
    ;
  }
  Serial.println("Setup starting");

  // set up three output pins for a RGB status LED
  ledInit();

#ifdef ENABLE_UART
  // Serial1 output is for DMX signalling to the MAX485 module
  Serial1.begin(250000, SERIAL_8N2);
#endif

  global.universe = 0;
  global.sequence = 0;
  global.length = 512;

#ifdef ENABLE_UART
  for (int i = 0; i < 512; i++)
    global.uart_data[i] = 0;
#endif

#ifdef ENABLE_I2S
#ifdef I2S_SUPER_SAFE
  Serial.println("Using super safe I2S timing");
#else
  Serial.println("Using normal I2S timing");
#endif
  // This must NOT be called before Serial.begin I2S output is on RX0 pin
  // which would be reset to input mode for serial data rather than output for I2S data.

  pinMode(I2S_PIN, OUTPUT); // Override default Serial initiation
  digitalWrite(I2S_PIN, 1); // Set pin high

  memset(&(global.i2s_data), 0x00, sizeof(global.i2s_data));
  memset(&(global.i2s_data.mark_before_break), 0xff, sizeof(global.i2s_data.mark_before_break));

  // 3 bits (12us) MAB. The MAB's LSB 0 acts as the start bit (low) for the null byte
  global.i2s_data.mark_after_break = (uint16_t) 0b000001110;

  // Set LSB to 0 for every byte to act as the start bit of the following byte.
  // Sending 7 stop bits in stead of 2 will please slow/buggy hardware and act
  // as the mark time between slots.
  for (int i = 0; i < DMX_CHANNELS; i++) {
    global.i2s_data.dmx_bytes[i] = (uint16_t) 0b0000000011111110;
  }
  // Set MSB NOT to 0 for the last byte because MBB (mark for break will follow)
  global.i2s_data.dmx_bytes[DMX_CHANNELS] = (uint16_t) 0b0000000011111111;

  i2s_begin();
  // 250.000 baud / 32 bits = 7812
  i2s_set_rate(7812);

  // Use this to fine tune frequency: should be 125 kHz
  //memset(&data, 0b01010101, sizeof(data));
#endif

  // The SPIFFS file system contains the html and javascript code for the web interface
  SPIFFS.begin();

  if (loadConfig()) {
    ledYellow();
    delay(1000);
  }
  else {
    ledRed();
    delay(1000);
  }

  WiFiManager wifiManager;
  wifiManager.setAPStaticIPConfig(IPAddress(192, 168, 1, 1), IPAddress(192, 168, 1, 1), IPAddress(255, 255, 255, 0));
  wifiManager.autoConnect(host);
  Serial.println("connected");

  if (WiFi.status() != WL_CONNECTED)
    ledRed();

#ifdef ENABLE_STANDALONE
  Serial.println("Starting WiFiManager (non-blocking mode)");
  wifiManager.setConfigPortalBlocking(false);
#else
  Serial.println("Starting WiFiManager (blocking mode)");
#endif

  WiFi.hostname(host);
  wifiManager.setAPStaticIPConfig(IPAddress(192, 168, 1, 1), IPAddress(192, 168, 1, 1), IPAddress(255, 255, 255, 0));

#ifdef STANDALONE_PASSWORD
  wifiManager.autoConnect(host, STANDALONE_PASSWORD);
#else
  wifiManager.autoConnect(host);
#endif
  Serial.println("connected");

  if (WiFi.status() == WL_CONNECTED)
    ledGreen();

#ifdef ENABLE_ARDUINO_OTA
  Serial.println("Initializing Arduino OTA");
  ArduinoOTA.setHostname(host);
  ArduinoOTA.setPassword(ARDUINO_OTA_PASSWORD);
  ArduinoOTA.onStart([]() {
    allBlack();
    digitalWrite(LED_B, ON);
  });
  ArduinoOTA.onError([](ota_error_t error) {
    Serial.printf("Error[%u]: ", error);
    allBlack();
    digitalWrite(LED_R, ON);
  });
  ArduinoOTA.onProgress([](unsigned int progress, unsigned int total) {
    analogWrite(LED_B, 4096 - (20 * millis()) % 4096);
    if (progress != last_ota_progress) {
      Serial.printf("OTA Progress: %u%%\n", (progress / (total / 100)));
      last_ota_progress = progress;
    }
  });
  ArduinoOTA.onEnd([]()   {
    allBlack();
    digitalWrite(LED_G, ON);
    delay(500);
    allBlack();
  });
  Serial.println("Arduino OTA init complete");

  if (WiFi.status() == WL_CONNECTED) {
    Serial.println("Starting Arduino OTA (setup)");
    ArduinoOTA.begin();
    arduinoOtaStarted = true;
  }
#endif

#ifdef ENABLE_WEBINTERFACE

  // this serves all URIs that can be resolved to a file on the SPIFFS filesystem
  server.onNotFound(handleNotFound);

  server.on("/", HTTP_GET, []() {
    tic_web = millis();
    handleRedirect("/index.html");
  });

  server.on("/defaults", HTTP_GET, []() {
    tic_web = millis();
    Serial.println("handleDefaults");
    handleStaticFile("/reload_success.html");
    defaultConfig();
    saveConfig();
    server.close();
    server.stop();
    ESP.restart();
  });

  server.on("/reconnect", HTTP_GET, []() {
    tic_web = millis();
    Serial.println("handleReconnect");
    handleStaticFile("/reload_success.html");
    ledRed();
    server.close();
    server.stop();
    delay(5000);
    WiFiManager wifiManager;
    wifiManager.resetSettings();
    wifiManager.setAPStaticIPConfig(IPAddress(192, 168, 1, 1), IPAddress(192, 168, 1, 1), IPAddress(255, 255, 255, 0));
    wifiManager.startConfigPortal(host);
    Serial.println("connected");
    server.begin();
    if (WiFi.status() == WL_CONNECTED)
      ledGreen();
  });

  server.on("/restart", HTTP_GET, []() {
    tic_web = millis();
    Serial.println("handleRestart");
    handleStaticFile("/reload_success.html");
    ledRed();
    server.close();
    server.stop();
    SPIFFS.end();
    delay(5000);
    ESP.restart();
  });

  server.on("/dir", HTTP_GET, [] {
    tic_web = millis();
    handleDirList();
  });

  server.on("/json", HTTP_PUT, [] {
    tic_web = millis();
    handleJSON();
  });

  server.on("/json", HTTP_POST, [] {
    tic_web = millis();
    handleJSON();
  });

  server.on("/json", HTTP_GET, [] {
    tic_web = millis();
    DynamicJsonDocument root(300);
    N_CONFIG_TO_JSON(universe, "universe");
    N_CONFIG_TO_JSON(channels, "channels");
    N_CONFIG_TO_JSON(delay, "delay");
    root["version"] = version;
    root["uptime"]  = long(millis() / 1000);
    root["packets"] = packetCounter;
    root["fps"]     = fps;
    String str;
    serializeJson(root, str);
    server.send(200, "application/json", str);
  });

  server.on("/update", HTTP_GET, [] {
    tic_web = millis();
    handleStaticFile("/update.html");
  });

  server.on("/update", HTTP_POST, handleUpdate1, handleUpdate2);

  // start the web server
  server.begin();

#endif // ifdef ENABLE_WEBINTERFACE

#ifdef ENABLE_MDNS
  // announce the hostname and web server through zeroconf
  MDNS.begin(host);
  MDNS.addService("http", "tcp", 80);
#endif

  artnet.begin();
  artnet.setArtDmxCallback(onDmxPacket);

  // initialize all timers
  tic_loop   = millis();
  tic_packet = millis();
  tic_fps    = millis();
  tic_web    = 0;

#ifdef ENABLE_UART
  tic_uart    = 0;
#endif

#ifdef ENABLE_I2S
  tic_i2s    = 0;
#endif

  Serial.println("Setup done");
} // setup

/*********************************************************************************/

void loop() {
  // handle wifiManager and arduinoOTA requests only when not receiving new DMX data
  long now = millis();
  if (now - last_packet_received > 1000) {
    wifiManager.process();
#ifdef ENABLE_ARDUINO_OTA
    if (WiFi.status() == WL_CONNECTED && !arduinoOtaStarted) {
      Serial.println("Starting Arduino OTA (loop)");
      ArduinoOTA.begin();
      arduinoOtaStarted = true; // remember that it started
    }
    ArduinoOTA.handle();
#endif
  }
  server.handleClient();

  if (WiFi.status() != WL_CONNECTED) {
    ledRed();
    delay(10);
#ifndef ENABLE_STANDALONE
    return;
#endif
  }

  if ((millis() - tic_web) < 5000) {
    // give feedback that the webinterface is active
    ledBlue();
    delay(25);
  }
  else  {
    ledGreen();
    artnet.read();

    // this section gets executed at a maximum rate of around 40Hz
    if ((millis() - tic_loop) > config.delay) {
      long now = millis();
      tic_loop = now;
      frameCounter++;

#ifdef ENABLE_UART
#ifdef USE_SERIAL_BREAK
      // switch to another baud rate, see https://forum.arduino.cc/index.php?topic=382040.0
      Serial1.flush();
      Serial1.begin(90000, SERIAL_8N2);
      while (Serial1.available()) Serial1.read();
      // send the break as a "slow" byte
      Serial1.write(0);
      // switch back to the original baud rate
      Serial1.flush();
      Serial1.begin(250000, SERIAL_8N2);
      while (Serial1.available()) Serial1.read();
#else
      // send break using low-level code
      SET_PERI_REG_MASK(UART_CONF0(SEROUT_UART), UART_TXD_BRK);
      delayMicroseconds(DMX_BREAK);
      CLEAR_PERI_REG_MASK(UART_CONF0(SEROUT_UART), UART_TXD_BRK);
      delayMicroseconds(DMX_MAB);
#endif

      Serial1.write(0); // Start-Byte
      // send out the value of the selected channels (up to 512)
      for (int i = 0; i < MIN(global.length, config.channels); i++) {
        Serial1.write(global.uart_data[i]);
      }

      uartCounter++;
      if ((now - tic_uart) > 1000 && uartCounter > 100) {
        // don't estimate the FPS too frequently
        float pps = (1000.0 * uartCounter) / (now - tic_uart);
        tic_uart = now;
        uartCounter = 0;
        Serial.printf("UART: %.1f p/s\n", pps);
      }
#endif

#ifdef ENABLE_I2S
      // From the comment in I2S.h:
      // "A frame is just a int16_t for mono, for stereo a frame is two int16_t, one for each channel."
      // Therefore we need to divide by 4 in total
      i2s_write_buffer((int16_t*) &global.i2s_data, sizeof(global.i2s_data) / 4);

      i2sCounter++;
      if ((now - tic_i2s) > 1000 && i2sCounter > 100) {
        // don't estimate the FPS too frequently
        float pps = (1000.0 * i2sCounter) / (now - tic_i2s);
        tic_i2s = now;
        i2sCounter = 0;
        Serial.printf("I2S: %.1f p/s\n", pps);
      }
#endif
    }
  }

#ifdef WITH_TEST_CODE
  testCode();
#endif

} // loop

/*********************************************************************************/

#ifdef ENABLE_I2S
// Reverse byte order because DMX expects LSB first but I2S sends MSB first.
byte flipByte(byte c) {
  c = ((c >> 1) & 0b01010101) | ((c << 1) & 0b10101010);
  c = ((c >> 2) & 0b00110011) | ((c << 2) & 0b11001100);
  return (c >> 4) | (c << 4);
}
#endif // ENABLE_I2S

/*********************************************************************************/

#ifdef WITH_TEST_CODE
void testCode() {
  long now = millis();
  uint8_t x = (now / 60) % 240;
  if (x > 120) {
    x = 240 - x;
  }

  //Serial.printf("x: %d\n", x);
#ifdef ENABLE_UART
  global.uart_data[1] =   x;// x 0 - 170
  global.uart_data[2] =   0;// x fine
  global.uart_data[3] =   x;// y: 0: -horz. 120: vert, 240: +horz
  global.uart_data[4] =   0;// y fine
  global.uart_data[5] =  30;// color wheel: red
  global.uart_data[6] =   0;// pattern
  global.uart_data[7] =   0;// strobe
  global.uart_data[8] = 150; // brightness
#endif // ENABLE_UART

#ifdef ENABLE_I2S
  global.i2s_data.dmx_bytes[1] = (flipByte(  x) << 8) | 0b0000000011111110;// x 0 - 170
  global.i2s_data.dmx_bytes[2] = (flipByte(  0) << 8) | 0b0000000011111110;// x fine
  global.i2s_data.dmx_bytes[3] = (flipByte(  x) << 8) | 0b0000000011111110;// y: 0: -horz. 120: vert, 240: +horz
  global.i2s_data.dmx_bytes[4] = (flipByte(  0) << 8) | 0b0000000011111110;// y fine
  global.i2s_data.dmx_bytes[5] = (flipByte( 30) << 8) | 0b0000000011111110; // color wheel: red
  global.i2s_data.dmx_bytes[6] = (flipByte(  0) << 8) | 0b0000000011111110;// pattern
  global.i2s_data.dmx_bytes[7] = (flipByte(  0) << 8) | 0b0000000011111110;// strobe
  global.i2s_data.dmx_bytes[8] = (flipByte(150) << 8) | 0b0000000011111110; // brightness
#endif // ENABLE_I2S
}
#endif // WITH_TEST_CODE