Беспроводной DMX512 приемник/передатчик

В данной статье я расскажу вам как создать передатчик и приемник DMX512 сигнала. Выложена принципиальная схема, схема платы, и вся разводка. Апаратная часть построена на микроконтролере avr ATMEGA 328 от компании Atmel. Приемник и передатчик могут передавать все 512 каналов управления. Без антенны базовая конфигурация работает до 100 метров в прямой видимости(сможет работать до 1км при установке антенны)

Сборка состоит из микроконтролера

• NRF24L01 два модуля.
• 12v Вход (5v и 3.3v регулятор напряжения)
• 2 x XLR вход и выход(папа и мама)
• 2 x Светодиода(для индикации)
• ATMEGA328p-pu микроконтроллер.
• 3 x 100ом резисторы.
• 1 x 10кОМ резистор.
• 3 x 10uF конденсаторы.
• переключатель каналов, джампер.
• 16mHZ кварц.

Для подключения радиомодуля использованы ножки аппаратного SPI микроконтроллера, поэтому разъемы подключения модуля и подключения программатор дублируют друг друга. Это сделано, чтобы удобней было прошивать микроконтроллер на отладночной платке, например, если использовать программатор который подает на схему 5 вольт, а для NRF24L01 это слишком большое напряжение. Чтобы перепрошить управляющий микроконтроллер, достаточно выдернуть трансивер с платы, перепрошить и всунуть его обратно - без лишней возни с перепайкой.

Существуют ситуации, когда где DMX кабель невозможно протянуть, или использование его просто не практично. Этот проект реализует беспроводную передачу сигнала DMX в диапазоне 2,4 ГГц, используя платформу Arduino и популярного модуля приемопередатчика NRF24L01 + из нордического полупроводника. ==== Протокол передачи ==== Прием и передача по протоколу DMX осуществляется на контроллере ATmega с помощью библиотеки DMXSerial. Реализация использует прерывания и является хорошей базой для реализации второго протокола на одном чипе. 2,4 Радиомодуль подключен к плате Arduino или микроконтроллеру ATmega с помощью интерфейса SPI. Библиотека для использования чипа находится здесь https://github.com/gcopeland/RF24 . После инициализации библиотеки можно передавать и принимать данные, используя прилагаемые функции библиотеки. Библиотека передает все команды и данные микросхемы nRF24L01 + также будет обрабатывать все детали передачи в фоновом режиме. ===== Скетч для микроконтроллера ===== <note warning>ВНИМАНИЕ: перед компиляцией и заливкой скетча в микроконтроллер, необходимо установить и добавить в компилятор библиотеки nRF24L01 и RF24</note> <file> FOR ATMEGA328 16mhz ONLY connection information… http://arduino-info.wikispaces.com/Nrf24L01-2.4GHz-HowTo SN75176 configuration : DMXrx NRFtx : pin 2 = 0v | pin 3 = 0v NRFrx DMXtx : pin 2 = 0v | pin 3 = 5v pin 6 = DMX+ | pin7 = DMX- Ensure 3.3v is used to supply NRF24L01 board !! the Nrf24L01 board can only transmit from channel 0 to 83 in the USA, therefore we shall limit it to 0-80 in steps of 5

#include <EEPROM.h> #include <SPI.h> #include <nRF24L01.h> library: https://github.com/maniacbug/RF24 #include <RF24.h> #include <Wire.h> #include <DMXSerial.h> library: http://www.mathertel.de/Arduino/DMXSerial.aspx #define MAX_DMX_CHANNELS 512 full DMX #define BYTES_PER_PACKET 16 usable bytes per packet #define PACKET_OVERHEAD 2 group and time stamp #define MAXPAYLOAD (BYTES_PER_PACKET+PACKET_OVERHEAD) max payload size for nrf24l01 #define MAXGROUPS (MAX_DMX_CHANNELS/BYTES_PER_PACKET) 32 groups of 16 channels = 512 DMX channels

16way hex channel selector - hex switch mounted with zero at top (see PCB layout) #define HEX_0 A4 #define HEX_1 A1 #define HEX_2 A2 #define HEX_3 A5 nRF24L01 control #define nRF_CE 9 Chip enable #define nRF_CSN 10 Chip select not LEDs #define LED_BLUE 6 BLUE PWM #define LED_RED 5 RED PWM sn76175 control #define DMX_NOT_EN 2 #define DMX_MODE 3 other #define ROLE A0 if low (jumper on) then RX otherwise TX

RF24 radio(nRF_CE,nRF_CSN);

unsigned long RXtimer, flashTimer, taskTimer, lastFlash, refreshTimer, radioTimer, rePairTimer; uint64_t RXTXaddress, pairingAddress = 0xF0F0F0F0F0LL; uint16_t rfQuality; uint8_t payload[MAXPAYLOAD], shadow_DMX[MAX_DMX_CHANNELS]; uint8_t timeStamp, lastStamp, bestChannel; uint8_t HEXchannel, _HEXchannel, RXTXchannel, pairingChannel = 80; boolean role, _role, group_send;

void setup(void) {

// set DMX/rs485 interface
pinMode(DMX_NOT_EN, OUTPUT); 
digitalWrite(DMX_NOT_EN, LOW); 
pinMode(DMX_MODE, OUTPUT);
// set bicolour LED
pinMode(LED_BLUE, OUTPUT); 
digitalWrite(LED_BLUE, LOW);
pinMode(LED_RED, OUTPUT); 
digitalWrite(LED_RED, LOW);
// set up ROLE switch
pinMode(ROLE, INPUT_PULLUP); 
// set up HEX channel select switch
pinMode(HEX_0, INPUT_PULLUP);
pinMode(HEX_1, INPUT_PULLUP);
pinMode(HEX_2, INPUT_PULLUP);
pinMode(HEX_3, INPUT_PULLUP);
if ( digitalRead(ROLE) ) { // jumper off : transmitter : initialise & read EEPROM
  init_EEPROM();
}
radio.begin();

test nRF board, if it doesnt reply then flash LED indefinately, or until it does reply while (!radio.isPVariant() ) { check if board connected

  if (digitalRead(ROLE)) { blue(); delay(500); off(); delay(500); }  // Wireless TX : if no rf comms then flash BLUE 50%
  else { red(); delay(500); off(); delay(500); }  // Wireless RX : if no rf comms then flash RED 50%
}

// generic radio stuff    
radio.setAutoAck(false);
radio.setPayloadSize(MAXPAYLOAD);
radio.setPALevel(RF24_PA_HIGH);    
radio.setDataRate(RF24_250KBPS); 
radio.setRetries(0,0);
//radio.setDataRate(RF24_1MBPS); 
//radio.setDataRate(RF24_2MBPS); 

HEXchannel = HEXread();

if this is a transmitter, do a channel scan, transmit network RXTXaddress and clean RXTXchannel during rePair (every 2 secs) only send clean channel data if channel selector is set to zero (send 0xFF if channel other than zero : manualPair)

if ( digitalRead(ROLE) ) { // jumper off : transmitter
  bestChannelScan(); // only do channel scan if this is a transmitter - bestChannel is required for manualPair and autoPair modes
  if (HEXchannel) { //  
    bestChannelDisplay(); // if HEX switch not zero display best channel number
  }
}

if this is a receiver, go into pairing mode and wait (indefinately) for pairing & channel data only use received (clean) channel data if channel selector is set to zero

else  {
  receivePairingAddress();
}
rePairTimer = flashTimer = taskTimer = millis(); // TXtimer =
DMXSerial.maxChannel(MAX_DMX_CHANNELS);
rfQuality = 0;
// read and initialise HEX switch and Role jumper
readPins(true);

} end of init void loop(void) { once per second, test for changes in HEX Switch and Role jumper (rx/tx)

if (millis() - taskTimer > 1000) {
  taskTimer = millis();
  readPins(false);
}

JUMPER OFF : DMX –> WIRELESS Tx LED Wireless TX : Solid BLUE, broken with very short flash of RED only if DMX data is being received.

if (digitalRead(ROLE)) { // if a wireless transmitter
// SEND OUT BURSTS OF RADIO DATA EVERY 30ms....
  for (uint8_t group = 0; group < MAXGROUPS; group++) { // scan through the groups of DMX data, 30 bytes at a time
    uint16_t group_ptr = group*BYTES_PER_PACKET; //30; // create group pointer for array
    if (millis() - refreshTimer > 1000) { // allow ALL radio data (full DMX array) to be send once per second, regardless of changes
      group_send = true; // force ALL send
      refreshTimer = millis();
    } //if refresh timer
    else { 
      group_send = false; // preset flag to false, only set it if there has been a data change since last time
    } // not refresh timer
    for (uint8_t chan = 1; chan < BYTES_PER_PACKET+1; chan++) {
      if ( DMXSerial.read(group_ptr+chan-1) != shadow_DMX[group_ptr+chan-1] ) { // compare test : current DMX against old DMX 
        shadow_DMX[group_ptr+chan-1] = DMXSerial.read(group_ptr+chan-1); // if changed, update shadow array of DMX data and payload
        group_send = true; // set flag so that THIS group packet gets sent
      } // if data compare
      payload[chan+1] = DMXSerial.read(group_ptr+chan-1); // ensure ALL up-to-date data gets through on this packet
    } // for chan
    if (group_send) { // only send the data that has changed, any data change in a group will result in whole group send
      payload[0] = group; // set first byte to point to group number (groups of 30 bytes)
      payload[1] = timeStamp++; // second byte helps us monitor consistency of reception at receiver with a continuous frame counter
      radio.write( payload, sizeof(payload) ); // dump payload to radio
    } // if group_send
  } // for group
  if ( (DMXSerial.noDataSince() < 2000) && (millis() > 1000) ) { // if DMX has been received within the last 2 seconds make LED flash
    if (!(millis() & 0b1111000000)) { 
      red(); 
    } 
    else { // SIMPLE DMX FLASHER
      digitalWrite(LED_RED,0); 
      analogWrite(LED_BLUE,5); // low level Blue
    }  
  }
  else { // no DMX data present, no flash
    digitalWrite(LED_RED,0); 
    analogWrite(LED_BLUE,5); 
  }
  // trigger rePair information send, just once every 2 seconds
  if (millis() - rePairTimer > 2000) {
    rePairTimer = millis();
    rePairTX(); // single burst of pairing information on pairing channel using pairing network address
  }
} // if role

JUMPER ON WIRELESS –> DMX LED Wireless RX : Solid RED, broken with flash of BLUE if wireless is being received (channel match) the gaps between the BLUE flashes are dependant on consistency of consecutive packets, relating to timeStamp

else {
  if (millis() - RXtimer > 20000) { // after 20 seconds without receving any radio data, try and rePair 
    receivePairingAddress();
  } 
  else if (millis() - RXtimer > 2000) { // after 2 seconds of no radio data, stop blinking
    rfQuality = 0; 
  } 
  if ( radio.available() ) {
    if (!rfQuality) { 
      rfQuality = 50; // just to show that channel and address are locked on !
    } 
    RXtimer = millis();
    radio.read( payload, sizeof(payload) ); // get data packet from radio 
    if ( payload[1] == (lastStamp+1) ) { // check for continuous timestamps, increase quality indicator if good
      if (rfQuality < 255) { rfQuality++; } 
    } 
    else { // if incontinuous, reduce quality indicator/LED brightness
     if (rfQuality > 50) { rfQuality--; }
    }  
    lastStamp = payload[1]; // reset last time stamp to current for checking next time
    for (uint8_t i = 0; i <BYTES_PER_PACKET; i++) {
      DMXSerial.write((BYTES_PER_PACKET*payload[0])+i, payload[i+2]); // spill radio data into dmx data array
    } 
  } // if radio avail
  lastFlash = millis() - flashTimer;
  if (lastFlash < 64) { 
    digitalWrite(LED_RED,0);
    analogWrite(LED_BLUE,rfQuality); // show rfQuality as brightness of BLUE LED 
  } 
  else if (lastFlash >= 64) { 
    digitalWrite(LED_BLUE,0);
    analogWrite(LED_RED,5); // switch back to RED at low level
  } 
  if (lastFlash > 1024) { 
    flashTimer = millis(); // reset timer after 1 second(ish)
  } 
} // else

} loop read HEX switch and Role jumper, if there has been a change in settings then an update can be made void readPins(boolean initialise) {

_HEXchannel = HEXread(); // get temp HEXchannel
_role = digitalRead(ROLE); // get temporary Role
if (_role != role || initialise) { // has the ROLE changed ?? - initialise will override any change in settings
  role = _role;
  if (role) { // JUMPER OFF : this is a wireless transmitter
    digitalWrite(DMX_MODE,LOW); // enable rs485 for input
    DMXSerial.init(DMXReceiver); // enable DMX to receive
    radio.openWritingPipe(RXTXaddress); // set network address
    radio.stopListening(); // start talking !
    digitalWrite(LED_RED,0);
    analogWrite(LED_BLUE,5); // low level BLUE to start...
  }
  else { // JUMPER ON : this is a wireless receiver
    digitalWrite(DMX_MODE,HIGH); // enable rs485 for output
    DMXSerial.init(DMXController); // enable DMX for output only
    radio.openReadingPipe(1,RXTXaddress); // set network address
    radio.startListening(); // start listening for data
    digitalWrite(LED_BLUE,0);
    analogWrite(LED_RED,5); // low level RED to start...
  }
}
if (_HEXchannel != HEXchannel || initialise) { // has the CHANNEL changed ? - 'initialise' overrides any change in settings
  HEXchannel = _HEXchannel;
  rfQuality = 0; // reset this so that led stops flashing
  if (!role) {
    radio.stopListening(); // if this is a receiver...
  }
  if (HEXchannel) { 
    RXTXchannel = HEXchannel*5; // create real channel number from HEX read
  } 
  radio.setChannel(RXTXchannel); // set the channel
  if (!role) {
    radio.startListening(); // if this is a receiver...
  }
}

}

void red(void) {

digitalWrite(LED_BLUE,0); 
digitalWrite(LED_RED,1); 

} void blue(void) {

digitalWrite(LED_BLUE,1); 
digitalWrite(LED_RED,0); 

} void off(void) {

digitalWrite(LED_BLUE,0); 
digitalWrite(LED_RED,0); 

}

manualPair & autoPair information selecting HEXchannel 0 instigates «autoPair» mode on transmitter and receivers, therefore channel zero cannot be used in manualPair mode The transmitter and receivers MUST be set to either ALL autoPair(0) or ALL manualPair(1-15) to work correctly manualPair mode can only select RXTXchannels 5 to 75 (via hex switch positions 1-15) manualPair & autoPair (on the Transmitter) has a 'bestChannelScan' on power-up autoPair : The best(quietest)channel will be transmitted with the network address on pairing manualPair : The best(quietest)channel is shown by number of blinks (shown as 3 groups of blinks) (bestChannelDisplay) The RXTXchannel number is 5 times that indicated - example 5 blinks = channel 60 In manualPair, the transmitter and all receivers must be manually set to that channel via the hex switch Transmitter : every 2 seconds, the transmitter sends its network address/pipe number as data on channel 80, using a a pairing address/pipe Receivers : on power up, receiver(s) are in pairing mode, receiver goes to channel 80 and listens on the pairing address/pipe for the network address and channel number to go to receivers change to the network channel and wait for DMX/Radio data to arrive. If any receiver loses pairing, after 20 seconds it will start to repair again.

void bestChannelScan(void) { uint8_t carriers[16], reps, i, best=200; for (reps=0; reps<200; reps++) { scan all channels 200 times for (i=1; i<16; i++) { radio.setChannel(i*5); scan from channel 5 to 75 in steps of 5

    radio.startListening();
    delayMicroseconds(128);
    radio.stopListening();
    if ( radio.testCarrier() )
      ++carriers[i]; // if there is any signal present, increase value in array
  } // i
} // reps
for (i=15; i>0; i--) { //  find quietest channel, starting from highest channel
  if (carriers[i] < best) {
    best = carriers[i]; // save quietest value
    RXTXchannel = i*5; //and save corresponding channel number
  }
}

}

BestChannel will only display if transmitter is not on HEX SWITCH 0 void bestChannelDisplay(void) { uint8_t i, x; for (x=0; x<3; x++) { for (i=0; i<RXTXchannel/5; i++) { blue(); delay(25); off(); delay(375); } delay(1000); } } read the value of the Hex Switch uint8_t HEXread(void) {

  return (!digitalRead(HEX_0)) | (!digitalRead(HEX_1) << 1) | (!digitalRead(HEX_2) << 2) | (!digitalRead(HEX_3) << 3);

}

reguarily, the transmitter sends out a short burst of the config data on the pairing channel and using the pairing address void rePairTX(void) { radio.openWritingPipe(pairingAddress); radio.setChannel(pairingChannel); radio.stopListening(); payload[0] = (uint8_t) (RXTXaddress); payload[1] = (uint8_t) (RXTXaddress » 8); payload[2] = (uint8_t) (RXTXaddress » 16); payload[3] = (uint8_t) (RXTXaddress » 24); payload[4] = (uint8_t) (RXTXaddress » 32); if (HEXread()) { payload[5] = 0xFF; } else { payload[5] = RXTXchannel; } radio.write( payload, sizeof(payload) ); dump pairing data to radio

radio.openWritingPipe(RXTXaddress);
radio.setChannel(RXTXchannel); 
radio.stopListening();

}

void receivePairingAddress(void) {

uint8_t p, q;
radio.stopListening();
radio.openReadingPipe(1,pairingAddress);
radio.setChannel(pairingChannel);
radio.startListening();
digitalWrite(LED_BLUE,LOW);
while ( !radio.available() ) { 
  analogWrite(LED_RED,p++); delay(2); // slowly pulse RED LED while awaiting pairing connection
} 
radio.read( payload, sizeof(payload) ); // get data packet from radio if available
RXTXaddress = (uint64_t)(payload[0]) | (uint64_t)(payload[1] << 8) | (uint64_t)(payload[2] << 16);
RXTXaddress |= (uint64_t)(payload[3] << 24) | (uint64_t)(payload[4] << 32); // get RXTX address from payload
if ( payload[5] == 0xFF ) {
  RXTXchannel = HEXread()*5; // use channel from hex switch
} 
else { 
  RXTXchannel = payload[5]; // use best channel from scan
} 
radio.stopListening();
radio.openReadingPipe(1,RXTXaddress); 
radio.setChannel(RXTXchannel);
radio.startListening();
RXtimer = millis();

}

void init_EEPROM(void) { do this only if a transmitter if the EEPROM hasnt already been set (all bytes at 0xFF) then set an address using 2 random numbers to make up unique 40bit address the address will be used in pairing. Once it has been set the first time it wont need to be set again if ( digitalRead(ROLE) ) { jumper off : transmitter

  if ( (EEPROM.read(0) == 0xff) && (EEPROM.read(1) == 0xff) ) {// check for uninitialised/used eeprom memory
    randomSeed(analogRead(A3)); // seed from unused floating analog port
    EEPROM.write(0,random(255)); // unique lowest byte only
    EEPROM.write(1,random(255)); // initialise 40 bit address number into eeprom, this makes up bytes 1-4 in address
  }
  RXTXaddress = (uint64_t) (EEPROM.read(0)) | (uint64_t)(EEPROM.read(1) << 8) | (uint64_t)(EEPROM.read(1) << 16);
  RXTXaddress |= (uint64_t)(EEPROM.read(1) << 24) | (uint64_t)(EEPROM.read(1) << 32); // reconstruct RXTXaddress from eeprom, byte 0 is unique, bytes 1-4 are the same
}

}

</file> #define ROLE A0 - Эта строка отвечает за прием и ли передачу. Если нужен приемник то A0, передатчик A1