Arduino Powered TCU Replacement

[wildBill83]

I have to wait on my watchdog and brownout boards to arrive, been killing my arduinos on some cranks...

[Domesticated]

What exactly have you been doing? I take it you're the kinda kinda guy who caused a shortage of op amps in lab lol.

[wildBill83]

I have never done automotive electronics, the power fluctuates a good deal and the arduino just doesn't like it. I haven't been able to smooth it out. It doesn't happen every time, just like 1 in 75 starts.

Also sometimes it just plain out scrambles the binary and does well ... strange things... and you have to reflash it.

Power spikes kill the board
brownouts scramble it

[Domesticated]

I have never done automotive electronics, the power fluctuates a good deal and the arduino just doesn't like it. I haven't been able to smooth it out. It doesn't happen every time, just like 1 in 75 starts.

Also sometimes it just plain out scrambles the binary and does well ... strange things... and you have to reflash it.

Power spikes kill the board
brownouts scramble it

Build a voltage regulator son! LOL.

[stevediraddo]

Build a voltage regulator son! LOL.

THIS. But dont choose a linear regulator, they will crap out as soon as you start your engine. Switching mode regulators all the way! And a big fat capacitor for the brownouts. Not like a 1/2 farad car audio capacitor but like a small supercap.

[wildBill83]

It turns out after looking at my previous attempts at filtering power I either forgot about one or another.

I just put together a protection circuit. It's so basic I'm not sure why I didn't do it right to begin with.

It's basically an 1N4000 series diode and a 10Ohm 2W resister in series with a 27V zener diode to ground for spikes and a .1uF cap for noise and an electrolytic cap on the power input to the arduino.

Basically a conglomeration of my pervious attempts. If it survives startups I'm a day closer than I was before. I'll get back to testing this week and leave the arduino in my car and fully enabled to see how it reacts.

[wildBill83]

This project is now derpicated. I did successfully get shifting and could use three different shifting maps for 3 different modes but the push button on demand shifting is not a good idea. I got tired of throwing money away, bottom line is that if you want tunable automatic shifting that is possible, if you want manual like shifting, do a 5sp swap.