[question/help] raw ola uart

[Aworldc]

Hi, sorry for this (probably) stupid question. i have a raspberry pi 5 and i need to use it's gpio to control 6 channels of normal dmx512.

I enabled the uart plugin and connected wires to some pins on the piI don't know what's wrong, but when i use the ola ui to turn up the channels the lights don't change.

I connected uart tx on the pi to pin 3 on the dmx cable. i connected ground on the pi to pin 1 on the dmx cable. I don't have any breakout board but as far as i know i don't need one.

Attached is an -l 4 log and copy of ola-uart config. log.txt

If anyone knows what i messed up, that would be great.

[peternewman]

Hi @Aworldc ,

Did you see the suggested schematic in the blog linked from the Plugin's readme documentation: http://eastertrail.blogspot.co.uk/2014/04/command-and-control-ii.html

There's also a copy of the plugin docs here: http://docs.openlighting.org/ola/conf/ola-uartdmx.conf.html

You might get better responses on our mailing list: https://groups.google.com/forum/#!forum/open-lighting

[Aworldc]

Did you see the suggested schematic in the blog linked from the Plugin's readme documentation: http://eastertrail.blogspot.co.uk/2014/04/command-and-control-ii.html

Yeah i saw that, but it uses some adapter board i don't have and can't get as there isn't enough time for it to get shipped by tomorrow morning

[peternewman]

Sorry but you're probably out of luck then. The UART on the Pi generates TTL level unbalanced signals, and DMX is balanced RS-485 level.

How many lights have you got? The only thing you could possibly do would be some horrible bodge of sending the TTL level into the RS-485 chip of one of the lights (on the TTL side). If you could put a bodge wire in to put it into transmit enable (rather than receive enable where it will be) you could possibly use that light in place of the adapter board to drive the others.

[Aworldc]

got 2 lights. this only has to work for 8 hours so a horrible bodge is completely fine.