Tinkerkit DMX Receiver - Relay
The DMX Relay Receiver is a DMX module that mounts four relays; they can be individually controlled using a DMX master like TinkerKit!’s DMX Master Shield. Each Relay supports up to 220V at 10A.
A single master can control up to 512 receivers individually (128 of these boards for example) sequentially connected.
The DMX Relay Receiver works also as a standalone USB board; in fact it mounts a micro-usb connector and the same microcontroller as the Arduino Leonardo.
The board itself is divided in three parts:
1. Relay output
Where the high-voltages connections are made. Each Relay has three outputs: the one in the middle is the common line, while the external ones are normally-open and normally-closed. Refer to the relay tutorial for more detailed information on hot to wire a relay properly.
BE ALWAYS SAFE WHEN WORKING WITH HIGH VOLTAGES, NEVER TOUCH THIS PART OF THE BOARD WHEN THE HIGH VOLTAGE CURRENT IS RUNNING THROUGH IT. ALWAYS DISCONNECT THE POWER FIRST!
2. DMX connections
Plug in here the wires from the Master Shield or another DMX Receiver. The connections are easy, D+ goes to D+, D- to D- and GND to GND. For the external power, the Relay module requires 12V.
DMX works with one master and up to 128 receivers, all connected to a single line. In order to send signals to the right output, each receiver is identified by an address from 0 to 512.
Each receiver has an address that is set from this pin interface. The address is expressed with a binary number where each pin correspond to a digit.
As you probably understood from the pictures, if the pin is down that digit is 0, while if it’s up it is 1. Mind that the number is written from right to left; the most significant digit is in fact on the far right. If you notice in the last example, where we select an address with the number 20 (10100 in binary), we start writing it from right to left. This address refers to the first relay on the board (the one with the number 1 label), all the others have addresses that are sequential to the first one.
e.g. if set the address of the board on 3 (101), if you want to turn on the first relay you have to write:
if you want to turn on the second:
and so on. This means that if you have multiple DMX receivers, you have to set their addresses with a gap of four numbers, in order to have full control on all the modules on the board.
This way of setting addresses can be a bit confusing at the beginning, that’s why we created this visual tool that helps to understand how it works.
Binary Value: 0
This is an example code used to control a DMX Relay Receiver with an address of 5, we turn each relay on sequentially and then off altogether.