Hello all,

I am absolutely tired of reading various application notes, example programs and datasheets available on the internet for DMX-512. I am trying to implement a simple LED light dimmer using DMX-512 protocol. I hae a DMX-512 controller console which has 5 sliders. 4 for controlling intensities of individual lights (i suppose) and 5th is called master as it alone can control the intensities of all the lights at once.

I am making a circuit using 89c51, RS485 transreciever, and LEDs Red Green and Blue and trying control their intensities using the console. I am finding it very difficult the overall concept of how to decode the DMX-512 signals, how to wait for frame break how to detect make after break etc.
I have configured the microcontroller UART in mode 2 to work at 250kbps with crystal of 16MHz (PCON bit 8 = 0). But I have had numerous failed attempts to decode the incoming data stream.

Can anyone please explain me this procedure STEP BY STEP in detail or give suitable pointers. This is urgent. Thanks in advance.

 

Hello,

Are you bound to use the 89c51?
Here is a circuit with the ATmega8515:
http://www.hoelscher-hi.de/hendrik/english/led.htm

It can drive 8 leds.
There are several examples for the different leds too.

Bertus

 

Yes I have to use 89C51. If possible I have to implement it on 89c2051 further. But I guess 89c51 would be good for making the first prototype.