Driving a 8 relays board by DMX with arpschuino.

8 relays board drived by DMX

For this first tutorial, let's see how to simply drive a 8 relays board by DMX with arpschuino.


* We have no agreement with Conrad company, images and links are just provided as examples.

Set up

Let's begin by connecting the adapter to the 8 relay board, either by welding it for final assembly or with female connectors.

In the first case, match the marks - and gnd and the + and vcc marks. Solder the 10 pins and cut the protruding legs.

adapter on 8 relays board

For removable mounting, solder the 8-pin socket on the underside of the adapter and connect it according to the markings.

removable adapter for 8 relays board

A relay behaves like a controlled switch, so it is connected to one of the two power cables of the device to be controlled. Check the voltage and current of the relays. Here with 10A / 250V maximum one can envisage to use them with devices of 2000W (for 250V, 1000W for 110V)!

On the 8-relay board we can see that there are 3 terminal blocks per relay, we connect our device as shown in the image below.

WARNING ! For safety reasons always work off. Do not connect to 110/230V at this point.

screw terminals

There is a triple male connector and a jumper on the 8 relays board. With the jumper as in the picture on the right, the relays are powered by the arpschuino board.

It is also possible, as in the photo on the left, to power the relays separately in 5V and to benefit from a galvanic isolation. This is the solution that must be adopted if you have an arpschuino first version (not an arpschuino²).


Source code

We can use the default arpschuino code, in this case it will be necessary to use an on / off curve in your console or DMX software.

Another approach is to reprogram the arpschuino. On our board, the relays are active and close the circuit when they receive a signal at low level (0V). You can use arpschuino 16 off / on available on the download page. In this case the outputs will be inverted , which may be useful for some applications, but impractical in most cases.

With arpschuino_2X8relays , the relays will be active at the high level.

Here the flip-flop is done at 50% (127 steps Dmx) but this value can very easily be changed. Just change line 39: #define toggles 127 .

code source

#define toggle 0 will trigger as soon as the level is greater than 0, while #define toggles 254 will trigger at max level.

Do not forget to remove the jumper from DMX in to reprogram the arpschuino, and then replace it.

Let's plug ?

All you have to do is connect the arpschuino and the 8 relays card with the ribbon cable, power the arpschuino (the red led should light up) and connect the Dmx cable. As soon as the signal is received, the green LED flashes quickly.

IMPORTANT: It is necessary to isolate the all completely before connecting to the mains.

You can now check it by sending DMX levels to the start adress and the 7 following ones. The relays should switch on and off.

It's working!

We can easily connect two relay boards on the arpschuino to enjoy 16 circuits.

A relay card and a arpower can also be used for 8 relay outputs and 8 graduated low-voltage outputs.

You can contact us at :

8 relays board user guide : PDF

8 relays board shematic : PDF