Frsky Hall Effect RPM Sensor ?

[nickxab]

Hello again
I have an monster truck with a nitro engine.
I wanna have RPM data of the engine, FrSky's optical sensor doesn't really help. I remember in past i saw something about a hall effect sensor
and magnet on the flywheel.
Did anyone try it ? If yes do i need one magnet ? can i have 3 on the flywheel and set it up as 3 blades on the firmware?
My hardware is this:
D8R-II plus
FSH-01 (the hub)

It's the old telemetry system.

PS: Sorry if post that on a wrong section

[kalle123]

Seen this thread?

https://openrcforums.com/forum/viewtopi ... 86&t=12169

cu KH

[nickxab]

Oooh this looks interesting.
I didn't understand if i can use my existing hub and just plug an arduino base hall sensor on it instead of the optical.

[MikeB]

The RPM input on the hub is connected directly to a processor pin. The three connections are 0V, signal, and 5V. I assume the signal is just pulses from the original, optical RPM sensor. Ideally keep the signal in the range 0-3.3V, although I believe the processor pin is 5V tolerant.

Mike

[jhsa]

A few years ago I have built an oXs (OpenXsensor) with RPM sensor. You need an Hall effect switch and a couple magnets. I think you can tell the code how many magnets you have installed.
And I actually never finished this project 100%. It consists of a Battery backup system, the RPM sensor, an onboard Glowplug driver controlled by the radio and with bad (open) glowplug detection, and a fuel level sensor. I never managed to finish the fuel level sensor and make it work reliably. So, the project is halted until I learn more about coding

João

[nickxab]

Hmm i see...well i have to experiment a bit...sadly i have no clue about coding

jhsa, i was reading about that on the github. actually my last questions was aimed for this project

I was thinning to use the existing Frsky hub
So i had something like this in my mind: (hall sensor) -> (arduino) -> (frsky hub) -> (receiver)
Could i use all old sensors with this project ? Currently i have these: Temp sensors (TEMS-01), Fuel Sensor (FGS-01), GPS (GPS-01), Battery sensor with the lcd, 3axis (TAS-01) and the RPM sensor (RPMS-01) which i wanna replace with a magnetic one.

Or do you guys think it's better to convert an arduino to hub and replace the frsky hub with arduino ?

Also i saw about the Hitec hub, looks pretty similar with Frsky's hub, does anyone has it ?

[nickxab]

UPDATE:
I plugged the hall sensor directly on the frsky hub.
I glued one magnet on a PC fan and i connected it to the PC so i could monitor and compare the results.
Sadly i have only one magnet at the moment (waiting for the new order to arrive) luckily on the firmware i could set the RPM to 1 blade so i gave it a go.

So here are my results.


Now i will wait for the magnets pack to arrive and test it with 3 magnets to see if it will be more accurate.