Connecting tachometer to Cerbo GX

DIY
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1

I have a W-connection on my alternator that I use with a physical gauge to show the RPM.

I would also like to have this visible on my Cerbo’s Boat dashboard.

I have read that I should use an optocoupler like a PC817 to get the signal into the digital I/O of the Cerbo to not cause any damage.
Can anyone confirm this is the safe way to do this?

2

I don’t think the Cerbo input is fast enough to catch that signal.

3

maybe this helps:

I would send the value by MQTT / NodeRED to the Venus System, no direct electrical connection

4

Wow, that looks interesting but also a little complex… :frowning: