Team thingSoC:

Published August 8, 2016 © LGPL

DMX-512 : Light & Relay Control

DMX-512 is the protocol used world-wide for theater lighting control, and here is an easy, low cost way to embed it in your projects!

BeginnerFull instructions provided1 hour7,308

Things used in this project

Hardware components

thingSoC RS485 Expansion

Software apps and online services

Arduino IDE

Story

The thingSoC RS485 module is a simple way to create RS485 "wired" networks of Arduino compatible AVR microprocessors. The thingSoC RS485 module can either be used as a thingSoC Base (populated with sockets) or a thingSoC Expansion module (populated with pins or stack-thru sockets). In this example, we are using each thingSoC RS485 module as a standalone Base (populated with sockets) , and can plug other Expansion modules (ESP8266, RS-232, Ethernet, etc.) into the thingSoC RS485.

The thingSoC RS485 module includes a wide voltage range RS-485 transceiver chip, with a termination matching circuit. This allows the thingSoC RS485 to be strapped for either 3.3V or 5.0V operation, depending on what you need to interface with.

In this example, we use the DMXSimple Arduino Library from tinker.it/PJRC for the DMX-512 Master node, and DMXSerial from Mattias Hertel for the DMX-512 Slave nodes. Below is a photo of a simple test setup for DMX-512 (and other RS-485 protocols like Modbus or VMB).

RS-485 Multidrop Testing Circuit

The DC Barrel Jack is used to provide 5 Volt DC Power to the system, the power draw is minimal( < 300mA), and a USB outlet or charger can be used.

The little "red" FTDI to RS485 breakout is used to monitor the RS485 transactions on the bus from either the host computer or protocol analyzer.

TSOC_RS485 #1 is the DMX-512 "master" node and transmits on the bus. It also has a Methane Sensor (Methane Click) installed on it, and can monitor Methane levels in an area, and transmit that data on a DMX-512 channel. The Methane Sensor requires 5.0 V operation, so the TSOC_RS485 master is strapped for 5V operation.

TSOC_RS485 #2 & #3 are DMX-512 "slave" nodes and receive on the bus. Each "slave" also has a dual (2) relay module (Relay Click) installed onto it, so that each node can control two different external devices using relays. They can each be assigned to different DMX-512 channels for control. The Relay Click requires 5.0 V operation, so the TSOC_RS485 slaves are strapped for 5V operation.

Installing the DMXSimple Library

The DMXSimple Library is installed from the Arduino Library manager :

Install DMXSimple Library

Installing the DMXSerial Library

The DMXSerial Library is installed from the Arduino Library manager :

Programming the DMX-512 Master Node

The DMX-512 "master" node and DMX-512 "slave" nodes use different programs. Open the tsoc_rs485_dmxMaster.ino sketch and upload it to the master node.

Program the Master Node

Programming the DMX-512 Slave Nodes

Open the tsoc_rs485_dmxSlave.ino sketch and upload it to the slave node(s).

Program the Slave Node(s)

Demo Testing Sequence

The attached Master Sketch just cycles through the addressed DMX-512 channels, turning them on and off in sequence. This will ensure that you have all your wiring correct and that the setup is working for you.

Happy Hacking !

Code

/* Welcome to DmxSimple. This library allows you to control DMX stage and
** architectural lighting and visual effects easily from Arduino. DmxSimple
** is compatible with the Tinker.it! DMX shield and all known DIY Arduino
** DMX control circuits.
**
** DmxSimple is available from: http://code.google.com/p/tinkerit/
** Help and support: http://groups.google.com/group/dmxsimple       */

/* To use DmxSimple, you will need the following line. Arduino will
** auto-insert it if you select Sketch > Import Library > DmxSimple. */

#include <DmxSimple.h>

#define MAXCHAN 254

const int RedPin =     A3;  // PWM output pin for Red Light.
const int GreenPin =   A2;  // PWM output pin for Green Light.
const int BluePin =     7;  // PWM output pin for Blue Light.
const int YellowPin =   8;  // PWM output pin for Yellow Light.
const int Relay1Pin =   3;
const int Relay2Pin =  10;

void setup() {
  /* enable LED outputs */
  pinMode(RedPin,    OUTPUT); // sets the digital pin as output
  pinMode(GreenPin,  OUTPUT);
  pinMode(BluePin,   OUTPUT);
  pinMode(YellowPin, OUTPUT);
  pinMode(Relay1Pin, OUTPUT);
  pinMode(Relay2Pin, OUTPUT);  
  digitalWrite(RedPin,    LOW);
  digitalWrite(GreenPin,  LOW);
  digitalWrite(BluePin,   LOW);
  digitalWrite(YellowPin, LOW);
  digitalWrite(Relay1Pin, LOW);
  digitalWrite(Relay2Pin, LOW);
  delay(200);
  digitalWrite(RedPin, HIGH);
  digitalWrite(GreenPin, HIGH);
  digitalWrite(BluePin, HIGH);
  /*
   * Configure RS-485 Driver Enable as Output for DMX512 Master
   * Rev4.0  = D5
   * Rev5.0  = D2
   */
  pinMode(2, OUTPUT);
  digitalWrite(2, HIGH);
  /* 
   *  If RDM512, Configure RS-485 Driver for RDM512 Input
   * Rev4.0  = D6
   * Rev5.0  = D0   */
  pinMode(0, INPUT);
 
  /* The most common pin for DMX output is pin 3, which DmxSimple
   * uses by default. If you need to change that, do it here. 
   * Rev4.0  = D4
   * Rev5.0  = D1
   */
  DmxSimple.usePin(1);

  /* DMX devices typically need to receive a complete set of channels
  ** even if you only need to adjust the first channel. You can
  ** easily change the number of channels sent here. If you don't
  ** do this, DmxSimple will set the maximum channel number to the
  ** highest channel you DmxSimple.write() to. */
  DmxSimple.maxChannel(MAXCHAN);

  /* turn on brightness channel(s) */
  DmxSimple.write(11, 255);
  digitalWrite(YellowPin, HIGH);
}

void loop() {
  int channum;
  byte level;

  digitalWrite(RedPin,    LOW);
  DmxSimple.write(12, 255);
  delay(1000);
  digitalWrite(RedPin,    HIGH);
  digitalWrite(GreenPin,  LOW);
  DmxSimple.write(12, 0);
  DmxSimple.write(13, 255);
  delay(1000);
  digitalWrite(GreenPin,  HIGH);
  digitalWrite(BluePin,   LOW);
  DmxSimple.write(13, 0);
  DmxSimple.write(14, 255);
  delay(1000);
  digitalWrite(BluePin,   HIGH);
  digitalWrite(YellowPin, LOW);
  DmxSimple.write(14, 0);
  DmxSimple.write(15, 255);
  delay(1000);
  digitalWrite(YellowPin, HIGH);
  digitalWrite(Relay1Pin, HIGH);
  DmxSimple.write(15, 0);
  DmxSimple.write(16, 255);
  delay(1000);
  digitalWrite(Relay1Pin, LOW);
  digitalWrite(Relay2Pin, HIGH);
  DmxSimple.write(16, 0);
  DmxSimple.write(17, 255);
  delay(1000);
  digitalWrite(Relay2Pin, LOW);
  DmxSimple.write(17, 0);
}

// - - - - -
// DmxSerial - A hardware supported interface to DMX.
// DmxSerialRecv.ino: Sample DMX application for retrieving 3 DMX values:
// address 1 (red) -> PWM Port A3
// address 2 (green) -> PWM Port A2
// address 3 (blue) -> PWM Port D7
// 
// Copyright (c) 2011-2015 by Matthias Hertel, http://www.mathertel.de
// This work is licensed under a BSD style license. See http://www.mathertel.de/License.aspx
// 
// Documentation and samples are available at http://www.mathertel.de/Arduino
// 25.07.2011 creation of the DmxSerial library.
// 10.09.2011 fully control the serial hardware register
//            without using the Arduino Serial (HardwareSerial) class to avoid ISR implementation conflicts.
// 01.12.2011 include file and extension changed to work with the Arduino 1.0 environment
// 28.12.2011 changed to channels 1..3 (RGB) for compatibility with the DmxSerialSend sample.
// 10.05.2012 added some lines to loop to show how to fall back to a default color when no data was received since some time.
// - - - - -

#include <DMXSerial.h>

// Constants for demo program

const int RedPin =     A3;  // PWM output pin for Red Light.
const int GreenPin =   A2;  // PWM output pin for Green Light.
const int BluePin =     7;  // PWM output pin for Blue Light.
const int YellowPin =   8;  // PWM output pin for Yellow Light.
const int Relay1Pin =   3;
const int Relay2Pin =  10;


#define RedChannel          12
#define RedDefaultLevel    255
#define GreenChannel        13
#define GreenDefaultLevel  255
#define BlueChannel         14
#define BlueDefaultLevel   255
#define YellowChannel       15
#define YellowDefaultLevel 255
#define Relay1Channel       16
#define Relay1DefaultLevel   0
#define Relay2Channel       17
#define Relay2DefaultLevel   0
void setup () {
  /* enable LED outputs */
  pinMode(RedPin,   OUTPUT); // sets the digital pin as output
  pinMode(GreenPin, OUTPUT);
  pinMode(BluePin,  OUTPUT);
  pinMode(YellowPin,  OUTPUT);
  pinMode(Relay1Pin,  OUTPUT);
  pinMode(Relay2Pin,  OUTPUT);
    
  DMXSerial.init(DMXReceiver);
  
  // set some default values
  DMXSerial.write(RedChannel, RedDefaultLevel);
  DMXSerial.write(GreenChannel, GreenDefaultLevel);
  DMXSerial.write(BlueChannel, BlueDefaultLevel);
  DMXSerial.write(YellowChannel, YellowDefaultLevel);
  DMXSerial.write(Relay1Channel, Relay1DefaultLevel);
  DMXSerial.write(Relay2Channel, Relay2DefaultLevel);    
}


void loop() {
  // Calculate how long no data backet was received
  unsigned long lastPacket = DMXSerial.noDataSince();
  
  if (lastPacket < 5000) {
    analogWrite(RedPin,  255-DMXSerial.read(RedChannel));
    analogWrite(GreenPin,  255-DMXSerial.read(GreenChannel));
    analogWrite(BluePin,   255-DMXSerial.read(BlueChannel));
    analogWrite(YellowPin, 255- DMXSerial.read(YellowChannel));
    digitalWrite(Relay1Pin, DMXSerial.read(Relay1Channel));
    digitalWrite(Relay2Pin, DMXSerial.read(Relay2Channel));
            
  } else {
    // Show pure red color, when no data was received since 5 seconds or more.
    analogWrite(RedPin,    RedDefaultLevel);
    analogWrite(GreenPin,  GreenDefaultLevel);
    analogWrite(BluePin,   BlueDefaultLevel);
    analogWrite(YellowPin, YellowDefaultLevel);
    digitalWrite(Relay1Pin, Relay1DefaultLevel);
    digitalWrite(Relay2Pin, Relay2DefaultLevel);
  }
}

Credits

Tom Moxon

16 projects • 38 followers

Chip Designer, Embedded Hardware and Software Design

Contact

Thanks to PaulStoffregen.

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DMX-512 : Light & Relay Control