Best board advice

[colinwebb]

Hi. I'm new to Arduino and have a project I'm looking to take analog to digital. I would appreciate advice on what board would work best. Also will I need any additional interfaces to make it work?

I've attached a crude diagram but to try and be clear, it's how I've been controlling my Daytime Running Lights on my car for years. I now want a smaller solution I can adjust.

The 14v VDC on the diagram is provided through a split charge caravan relay. This ensures the DRL are only lit when engines running not on aux power. Relay 1 then powers relay 2&3. The DRLs come on untill the left or right indicator (left R2 right r3) is turned on, this then throws the relay for that side and the capacitor keeps it thrown so the DRL that side stays off for 2 seconds after the final indicator blink then comes back on.

I would like to use Arduino to ditch the relays and perform the following.

1. DRL turn on after voltage reaches 14v
2. When voltage is received from indicator the DRL on that side is dimmed (preferred) or turned off untill 2 seconds after indicator is cancelled.
3. turn DRLs off if dipped beam is turned on.

Thanks for any advice

[Robin2]

Image from Original Post so we don't have to download it. See this Simple Image Posting Guide

...R

[Robin2]

I don't think your diagram matches your description. It seems to me when relay1 is powered it turns the others off. And there is no reference in the diagram to a turn indicator or a capacitor.

In any case, any Arduino should be able to deal with the logic.

If the relays are 12v automotive relays then you will need a transistor between the Arduino and the relay coil as the Arduino I/O pins cannot provide the current needed for a relay coil.

And if the Arduino is to detect voltages from the car system you will need voltage dividers to ensure the voltage on the Arduino pins NEVER exceeds 5v.

For both inputs and outputs using opto-isolators would be a good idea as car electrical systems can be very noisy.

...R