Hi, I've got an Arduino mega 2560 and am using this shield:
Sorry if this is posted in the wrong section.
I'm using the dmx simple library and it is set up to output on pin 4. I have tried using other pins with a long jumper and the issue remains when it occurs.
The issue:
Sometimes when sending dmx info to my lights from the board and shield listed above, data won't send or it sends random data unless I lightly touch one or more of the pins on the Arduino.
Notes:
-I have used known working code multiple times
-I've used different Arduino mega 2560's to test this issue
-I've tried different lights, dmx cables, tried mic xlr cables, tried different usb-b cables with and without rf chokes
-I've tried it with and without my laptop plugged in (trying to see if it was a ground loop as the shield is non isolating), and even plugged my Arduino into a USB phone charging dongle
-I do have my Arduino sitting next to me on my couch which is either fake leather or a thin real leather, I don't know if that could carry any amount of capacitance that could mess with the serial ports and cause it to spaz out.
I only chock this up to capacitance since having my finger touching pin 2 or occasionally pin 4 (or the pin that I have designated for the output to the dmx shield which uses a max485 chip without an optoisolator) will make the issue go away. Also unsure if it's just a lack of enough power being supplied.
I've already emailed the supplier of this board to get any insight into this issue, just waiting on a reply.
I would appreciate any ideas as to what could be causing this.
I'm posting this while on break at work but I can post the code later tonight if anyone needs to see it.