Attaching a pdf I made with instructions on how to build and program.

You will need and Arduino
A DMM
Another Arduino to burn the bootloader
The Arduino IDE
PATIENCE!
Soldering skills...

So question... What connectors would people like to see with these?

Deans would be great. Those might be the most popular.

XT60

4mm bullet

Figures... lol

XT60.

I ordered some of the DRV5057A4 sensors and they came in today. I made a quick circuit to test them out. To be honest, the results are less than stellar. So far I can't get the resolution below 8 using the 328p chip. I am going to rewrite the code and try it out with an esp32 to see if the faster clock will provide better resolution.

The HULK, lol.
Purple pcb and green case. Max reading of about 3200 gauss.

That looks really nice.

Did you ever get your car taken care of?

I did! My car broke down on the way to its service appointment. Was a lot of fun, lol.

Trying out my unit with my Hobbywing rotor. Don't know what the rating is supposed to be but it seems in the right ballpark. Only criticism I have at this point is that I had to move the rotor to the right as much as possible to align it over all 3 sensors, where it was very close to falling off the mount. Not sure if that's specific to Hobbywing.

I don't know if it is only specific to the Hobbywing because there are a lot of rotors out there I haven't tested. I know you have to move the Motiv MC4 rotors over a bit and the new Reedy, but there is still plenty of rotor shaft left after shimming.

But, after reading your post I went and took the rotor out of my Hobbywing 5.0. It is just like you posted, you have to shim it quite a bit. There is good news though, the magnetic strength at the middle of the rotor has a decently large sweet spot. So if it is off center 2-3 millimeters it is still fine.

I measured my rotor strength in my 5.0 at 1810/1785 on my Rotor Master and on the Fantom it measured 1800/1780. My unit measures slightly higher than the Fantom, but it does for all my rotors.


I can increase the width of the rotor holder on left side by 1mm , but I can't go too much or it will push some rotors too far to the right. Trinity rotors generally get shimmed out 1.5-2mm, so there isn't much room to work with.

As an update to the Hobbywing rotors. It will read on the Fantom, but you have to push the rotor up the step on the shaft. On the magnalyser it gives bad readings. So my unit may actually be the best unit right now to measure the Hobbywing rotors. Interesting... I'll make a video later, but right now I have to go buy a new (real) car, lol.

Here is a video I just made using a Trinity certified rotor and then the Hobbywing rotor. I tested on the Magnalyser, Fantom, and my unit.

https://youtu.be/-9H5F99PRV8?si=wPU9bO85uTxm-qF7