Wiring the controller modules

Setting up the power supply

This may seem an odd place/time to do this but it’s probably safer to do this at this point. The power supply may be set at the factory to deliver maximum voltage and that could damage components. Once adjusted the power supply will maintain the set voltage almost regardless of the supply voltage.

Research suggests that the optimum voltage to supply to an Arduino is 7 volts. All the other modules in this controller take their power from the Arduino which drops the supplied voltage to 5v. Putting a power supply between the Arduino and the vehicle electrics helps safeguard the Arduino from voltage spikes.

Connect a volt meter across the output of the power supply module (out + and out -). Connect the In+ and In- to a 12v battery or power source. Once connected, adjust the potentiometer/trimmer until the volt meter reads 7v DC. It may take several turns of the adjuster before you see any change in the output voltage.