DMX Serial Issue [Solved]

Forum 2005-2010 (read only) Hardware Troubleshooting
1

Hi,
i am trying to make a DMX Controler with the Arduino.
i have all the serial port working normally with the UART in the arduino (pin 1 TX)
BUT...
In order to respect the DMX protocol i need to generate a break on the serial port (LOW for at least 88usecond)
That is where the problem start,

  if (full_dmx_channel == 0)
  {
//    pinMode(1, OUTPUT);
    digitalWrite(1,LOW);
    delay(1000);
    digitalWrite(1,HIGH);
  }
  Serial.print((char)full_dmx_channel, BYTE);
  full_dmx_channel++;
  if (full_dmx_channel>512)
    full_dmx_channel = 0;

in this part, i actually climb the delay to 1 second to debug, with or without the pinMode it doesn't want to write a zero?
Anyone have a idea?
Thank in advance
Patgadget
Montreal

2

i Think i found it, need to Disable port TXEN0 to 0
will test it and be back
Patgadget

3

As i though, not enabling the UART and waiting for it to empty did the job.
then i could do what i want with the pin

  if (full_dmx_channel == 0)
  {
    UCSR0B = UCSR0B & ~0x08;
    delayMicroseconds(120);
    pinMode(1, OUTPUT);
    digitalWrite(1,LOW);
    delayMicroseconds(120);
    digitalWrite(1,HIGH);
    delayMicroseconds(12);
    UCSR0B = UCSR0B | 0x08;
  }