Avoid a headache. Separate power supplies recommended

As you know I have been posting about problems with supposed EMI interference of my CCTV video signal, my A/D converters, ESC’s, T100’s, you name it. Just a lot of erratic behavior that was frustrating and unexplainable. I was pretty much blaming it on EMI from the ESC outputs. Well, I have good news. Completely separating the CCTV power supply from the Arduino 328 processor power source has eliminated all of the above. I am now using a separate battery and ground for the CCTV and 328 processor. Luckily there is plenty of room in my control box for a second battery. I guess the high frequency signals from the video circuitry was finding its’ way into the processor through the common power supply. I now have the video signal going through a twisted pair with its’ own ground wire. Just testing in the garage shows no ESC interference on the video signal, but until I actually test out in the water, I’ll just keep my fingers crossed. A/D converters in the 328 read perfectly and the ESC is working great.

A down side is I had to use two more wires from topside for the CCTV power supply. Before I get my vertical/depth control system going I will have to come up with a 2-wire serial communication system for all of my control functions. I have a second Metro Mini processor on its’ way and will be installing it in the topside control box. Setting up a 485 serial comm system will be a challenge for me but I will get it done.

Thanks for the help everyone. Don’t forget to see my underwater videos on my YouTube channel Richard Fast.

Richard

Richard,

Great! Thanks for the update and glad that separating the power supplies helped. That’s very interesting - I’ve never seen that before.

I think moving to RS485 will be a good move and will enable you to do lots of cool new stuff.

Best,

Rusty