[woodcote]

@jJuniorHRW

The diagram you posted shows how to connect the Arduino into a four-lane track (using UK slot car club standard 3-pin plug controller hook-ups), where the relay board is being used to control the track power on each lane - eg a dead start, end of timed race or track call (using the button).

There are also connections shown from each lane to inputs 4-7 on the Arduino. I presume this is a sort of shorthand for “sensor signal from this lane” - as simply attaching a wire from the lane to the Ardino input won’t work, as 1. it makes no functional sense and 2. anything input above 5V will damage the board.

So if you wanted to use a deadstrip to create your sensor signal, search a wiring diagram for a deadstrip (the BSCRA site is my go-to resource). You can then use diagram you posted to see what inputs on the Arduino each lane needs to go, BUT to wire directly into the Arduino inputs will risk serious damage to the board. 

You could use a hefty resistor to modulate the signal, but I think the only completely safe way to protect the board is to completely de-couple the deadstrip output from the Arduino input - and that’s what the optocoupler does. You will need one optocoupler relay per lane - they are available in 1,2 and 4 relay modules.

BTW, I think one of us probably needs to download the latest version of Race Coordinator and see if the interface document has been updated for a deadstrip.