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Avoid a headache. Separate power supplies recommended

(Richard) #1

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.


(Rusty) #2


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.