I am building a "digital dash" for my motorcycle, a 1999 Royal Enfield Bullet. It uses a GPS module for speed, distance and acceleration (0 - 40, 0 - 60). I also monitor battery voltage vis a potential divider and an analogue input. My problem is that it keeps locking up or resetting at random. It only does this when I power it via the bikes loom. If I use a battery pack and do not connect it in any way to the loom then it works fine (apart from not monitoring battery voltage of course!).
I am using a 7805 voltage regulator with 100 uf electrolytic capacitors between the input and output lines of the regulator and ground. There is also a 4 mH toroidal suppression choke on the input.
Any thoughts or suggestions?