TL;DR @ bottom
I bought a bluetooth receiver for the car because the stock head unit didn't receive A2DP capabilities until the next year model,
So I bought one knowing the reviews said that you had to keep turning it on when it would "sleep". I thought, no problem, I'll just remove the internal battery, then it will only get power when the car comes on, and "boot". I did some testing still in stock form yesterday when I got it . After it powers off/sleeps, I can hold the button in that turns it on and activates the pairing procedure for as long as I want and it will pair and operate normally. That was encouraging for my plans. Tonight, I de-soldered the battery, and shorted the button/switch with a jumper wire. Plugged the 5v USB cable in, it started up, paired, and played music for 10 mins straight, good enough for me. Put it back together, and of course it starts throwing a fit. I've figured out that if it gets power, even for a second, loses power, then on the 2nd power application - it throws the fit and won't work. Error's out I guess. It takes it 1.5 minutes to reset and work again on the first plug in.
The problem is when the car is starting. It applies the power for a second before the starter engages thus cutting power, then after it's running it gives power again. This trips something in the circuit causing it to need the 1.5 min timeout again.
I've been trying to brush up on capacitors and resistors for the past hour, but I'm getting myself nowhere. Would it be possible to add a resistor and capacitor to the positive and negative pins on the input to delay it? Or would that require a huge capacitor? I'm only needing to delay it for maybe 5-10 seconds max. I know I could always configure the 5v source in the car to always be on, but that's probably not ideal. Plus, this little thing is easier to disassemble lol I've seen some 5v time delay relays but I would believe I can modify the existing circuit somehow. I hope I'm not way off in left field here, and you guys can understand what I'm trying to accomplish.
TL;DR - I need to delay power from 5v source for 5-10s going to the input of the circuit by modifying the existing circuit.
Any comments or suggestions are appreciated. Thanks for reading!