I just got done setting up FrSky Integration and the RPM reading I'm getting is fluctuating all over the place.

Here's my equipment...
Trex 470
Align RCE BL50X Esc
Hobbywing RPM Sensor
Sprit II FBL
Taranis X9D transmitter and X8R receiver

I've got the RPM sensor plugged into the Ele/Pit/Ail port on the Spirit
The FrSky Integration cable long end is in the Sys port on the Spirit

When the motor is not running I show 0 RPM on the telemetry screen.
When I give it a little bit of throttle I get an RPM reading, but it keeps changing. Example: 933 to 12,567 to 1250 to 7653, etc. The reading changes 2 to 3 times per second.
For the RPM sensor, I removed the heat shrink from two of the ESC motor connectors, soldered the sensor wires to the outside of the connectors, and the put on new heat shrink.

This is the sensor I have...
https://www.helidirect.com/products/hob ... oltage-esc

Any ideas?

Additional information. I had a standard 3 wire servo cable going from the sensor to the FBL. I then found in the online manual where I'm only supposed to have the RPM signal only going to the "Pit" (middle) pin of the Ele/Pit/Ail connector. I've since re-done my connector to have only the signal pin from the sensor going to the Pitch pin. This didn't change anything.

I then found in the manual where it says to try increasing the RPM Sensor Filter setting in the Expert settings if you have a noisy signal. I changed it from 6 to the max value of 8 and I'm still having the same issue.

Also - I checked the RPM by using the Spirit application, General Tab, Governor/Throttle Settings, Tester Button. It's the same whether I get it there or via telemetry.

Went to dinner. While waiting for my table I figured it out.
It turns out I'm just a dummy.

I had the signal pin going from the sensor to the Spirit, but I didn't have anything bringing power to the sensor. I took the positive and negative wires and ran them to the unused Aux 2 port on the FBL and that took care of everything.

Thank you for the message and helpful details.

In case of any question feel free to ask.

_________________
Spirit System developer