I want to use an Arduino (maybe Nano, maybe MEGA) in my motorcycle (a new KTM with lots of electronics). I checked my test circuit (with the MEGA) and it uses about 100mA (with 5V connected to the 5V pin).
Edit: the bike has a 12v battery and when it's on the generator pushes this up to about 14.3v.
For my first tests I used a 3 terminals DC/DC Regulator with output 5V for the Arduino power supply. If the ignition is on the Arduino works. As soon as I start the bike the Arduino restarts every couple of seconds.
Currently I used the BP5293 DC/DC Regulator because it has 2% precision. Currently I don't have any capacitors on the input or output terminals of that regulator.
I guess I have the following options:
a) Use the BP5293 and add capacitors on the input and/or output terminals. In the datasheet an output capacitor of about 10-330uF is recommended. For the input it recommends a capacitor but without any value given.
b) Use another regulator to 5V
c) Use a regulator to i.e. 7V and then connect that to the Arduino power input and let the Arduino do the filtering of the input.
What is the proper solution and what are suitable values for the capacitors?
I have 100nF ceramic capacitors and Low ESR electrolyte capacitors with 6.3V, 16V and 35V from 68uF up to 3300uF in stock. Obviously I could just try but I prefer to know how it should be done.
Connect ceramic capacitor, recommended 10μF
from the datasheet. I'd start with the input side, as the Arduino boards already have some capacitors on the board itself. Low ESR electrolytic, instead of ceramic, is most likely fine. Just make sure you have the correct polarity. I'd go for the 35V rating, just to be sure.