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Hall effect sensors

I am looking to upgrade a project I built last year. The project involved modifying an elliptical cross trainer to control the playback speed of an MP3 being played on a Raspberry Pi.

It was done with some custom python code and a hall effect sensor.

I am now looking to do the same thing with a real bike. But the use of a ‘normal’ bike means that I am looking to use the standard spoke-mounted magnet from a bike computer kit. The one I have needs to be within a few millimetres of the sensor.

If the sensor I am currently using is one of these:
https://components101.com/a3144-hall-effect-sensor

Am I right in assuming it should be possible to get a more-sensitive sensor, rather than trying to mount a stronger magnet to the spoke? If so, which one would be recommended?

Thanks

Hi Michael,

That sounds like a pretty neat project!

I’ve taken a look at the datasheet on the product page you linked to:

Looks like you need something with a B_op of less than 70 Gauss. I’d suggest using one of these:


And here’s the relevant section from the datasheet:

You could also just use stronger magnets, or move them closer. I’d also suggest considering adding multiple magnets evenly spaced around the wheel to improve your system’s sensitivity to acceleration.

Regards,
Oliver
Support | Core Electronics

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