Using Uno with DMX Shield

Hey guys,

So I am trying to control a dmx fixture using my Arduino Uno here, and I've purchased a shield for it, which can be found here. Apparently the library that comes with it is garbage, so people recommend using DmxSimple.

Since I still wanted to have serial access to the Uno, I am using pins 3 and 4 instead of 0 and 1. Unfortunately, this doesn't seem to work. My fixture never receives any valid DMX commands. It should be noted with this board that there are various jumpers on it, and so I have them set as follows:

EN <-- EN(with line on top) Slave --> DE TX-io <-- TX-UART RX-io <-- RX-UART

Now, I have tried researching this a bit on the forums here, but I didn't find much that was relevant or actually included a solution.

Below is my code:


void setup() {

int oldVal = 0;
void loop() {
  int val = analogRead(A0);
  if ((oldVal - 15 > val || oldVal + 15 < val) && oldVal != val) {
    for (int i=1;i<=24;i++) {
      DmxSimple.write(i, val/4);
    oldVal = val;

Basically what I'm trying to do here is read the value of a pot and set DMX values accordingly. Reading the pot works fine, and provides suitable values (I just have to divide it by 4 to match the 256 scheme of DMX).

Let me know if you guys have any suggestions as to how to get this whole thing to work.

Thanks! Emanuel