DTAForum.com - a forum for the DTA ECU

Hi, I'm setting up to use a NPN speed sensor which will be used for STACK speedo and ecu. Being as the ecu cannot output a car speed, I could run the sensor to the speedo and then use the output from that to drive the ecu input. This is a 5v DC square wave output.
I assume for the ecu input to work, it will also need the ecu ground back to the speedo/sensor. Will this be ok, shared with the speedo which is 12v? Or should I just share the signal from the sensor to the speedo and ecu? And share the grounds?

ECU can be configured to output road speed, something like this but you will have to put your own settings in.

Just use same signal for both, it won't care.