Motec M150 vehicle speed output

Hi all,

I would like to send the vehicle speed out from a Motec M150 to an '80s (Veglia) electronic speedometer / odometer. This speedo/odo is looking for a frequency signal. Essentially, I need the same thing I use for the tach output (frequency – not duty cycle – based on engine speed), but for vehicle speed.

Is this possible without going into custom firmware / development license territory?

Thanks in advance.

Have you considered just driving the speedo with an appropriate sensor / trigger combo from one of the output shafts (what did the OEM system look like?)

You are correct there isn't an equivalent "Speedo" output to the Engine "Tacho" output in the GPxx packages. That's a simple thing to add however if you did have a custom firmware package.

There are also GPS-based speedo output devices -- hot rod guys use them.

Another possibility -- use a small development board to receive a CAN signal and produce a frequency output (and perhaps drive other display lights, etc) Something like this: https://www.autosportlabs.com/product/esp32-can-x2-dual-can-bus-automotive-grade-development-board/

The OEM system uses a current output sensor (1mA - 10mA based on speed). This is sent to an crude circuit behind the speedo that converts to a 12v frequency that drives the speedo needle and odometer. That circuit is NLA, and mine went kaput.

I could find a way to repair the circuit, and then split the signal from the sensor to the speedo / ECU, but then I'd need to find a way to calibrate for the different tire sizes I am running (something easy to do in the ECU). The whole thing seemed more trouble than it's worth.

Bummer about the GPxx package not having a speedo output similar to the tacho. That would seem kind of basic, but what do I know.

I like the CAN idea. That has to be cheaper than going the development license route (even if this feature is trivial to enable once I have the license).

Thanks for the tips.