Hall sensor
TBD: test the TMAG5123D version on a rectangular magnet
https://www.ti.com/product/TMAG5123#design-tools-simulation
Tests
Beach test 100% speed
The rc car was placed on the bench an a cylindrical magnet was attached on the wheel and the sensor mounted just next too it. The motors was supplied with a constant 5.5V and left for ~5sec until the rpm settled.
we can see a frequency of ~46Hz and a delta on the low pulse of +-0.129ms. Over the period of 21.7ms it looks like we have a delta of less then 1%. This is most likely due to the gearbox, differential drive and/or the sampling time of the sensor, which is 0.1ms or 10kHz.