24 Ch Custom DMX Controller

Relay controller W/ DMX upgrade

When I started running my small haunted house the controllers I used were very simple and standalone. The more props I built the more I found a need for channels of control. Over the years I changed the design and function of these relay boards I was using. This will walk thought the building of the 4th generation of the controller I was using.

It uses a custom DMX control board to address each relay and will be controlled using Visual Show Automation or any DMX Program.


Click Here for parts list

This list will give you a good idea of the parts that you will need to make this project. Some tools you might need will be a soldering iron, drill, screw drivers, pliers and wire cutters.

New Enclosure And power boxes.
The enclosure for this project was a simple plastic box I found from an old satellite setup. The power boxes were metal outlet boxes with standard outlets installed inside. Each box it set up for 2 controllable outlets.

Relay board & High Voltage wiring:
Use Caution when working with 120VAC, It is dangerous and can kill you. If you dont know what your doing find someone that does and ask for help. This is provided for information only, I am not responsible for what you do with it. Please take the proper precautions.

The wiring for this project uses all 3 wires in an extension cord the black and white wires are used to address the individual sockets and the green is used to connect the neutral side. Each socket is split to allow control of 2 lights per box. The wiring is pretty simple, the relays share a common side and each relay handles one socket, all the green wires that come from the box are tied together. I split the board right down the middle and use 2 plugs so that the load can be split on 2 breakers, allowing it to handle a larger amp load if needed. Since this will only be used to control incandescent lights I did not connect the ground pin to the outlets.


DMX Control board:
The first time I made this board it did not work, I set it up again and it works perfectly, the next step will be to solder 3 of them together on a board for final installation.
I have finished programming all of the chips I will be using for the DMX control boards. In addition to the three that will run this relay light controller, I will be making 4 other controllers to run air valves and mechanical relays.

Click here for the Firmware

The only changes made to the firmware is the addressing line. I choose to use a programmed start address instead of a switch select one. so the start addresses are defined in the firmware.
Since the start address is defined in the firmware parts of the circuit are not needed and thus left out of the final build. The entire addressing section and the eeprom can both be left out.

Power supply:
The power supply for this relay setup will be in a few parts. First there are 2- 120 volt power connectors, this will supply the lights connected to the board with the power they need. Second will be a transformer putting out 15 volts, this will supply the voltage needed by the relays to switch on and off and provide power to the DMX network interface. The 15 volts will be regulated down to 5 volts that the SX28 chips need.

Computer, DMX setup and software:
The computer I used to test this is an HP mini laptop with a 1.6 ghz processor and 2 gigs of ram. I used 2 different software programs, the first was for initial testing which was trackskull This is a program that is great for testing and recording DMX or other signals. The second program I used is VSA, this is a show automation software. Both allow you to send dmx signals over a network and control a large number of devices. I will be using VSA to control everything thing in the haunted house during the season. For the DMX signal I bought a enttec USB-to-DMX controller. The open version was enough for what i am doing, I will eventually go to the pro version to allow for a second DMX universe.

Testing during and after construction:


Completed system
After installing the last few parts to complete the relay board and finish testing. everything works perfect and it is ready for Halloween.

Original concept for DMX Controller

If you need more information Email me