I'm building my own motorcycle quickshifter with gear indicator. Everything is done except of one thing - namely powering arduino from motorcycle battery.
When I power arduino from USB it's working very good, not a single problem, but when I power it using that circuit it's going crazy it keeps on sensing gear changes (I'm using hall effect sensor which when i'm not changing gear is like 240 on analog input and when i wnage gear it's going up to 360), and rebooting itself over and over.
What could be the problem?
What about using STEP-UP 12V (to make it 12V even when 12V voltage regulator is in drop mode (Vin lower than 12V)) after 12V voltage regulator (I have to use that, because there is sametimes more than 12V on motorcycle 12V wire)?
Interference from the rest of the electrics on the bike.
This is only to be expected given that you seem to have taken no precautions against it. There is no sure fire cure you have to work on it until you get it working.
Things like good supply decoupling shielded wiring to your sensors. Spike protection and surge protection are all things that need considering.
I haven't had much experience with it but automotive electrical systems can be pretty nasty. I would look into ways of powering arduinos from car batteries.
I think i've found the solution. I've solvered capacitors to voltage regulator wrong way. Date sheet sayd there should be 330nF between Vin and GDN, and 100nF between Vout and GDN. Before i mad that the oposite way. Now i have soldered that again but good way and so far thats working well.