Reliable hall effect sensor to determine wheel RPM

[Seya]

I have a project:

Bike using a hub motor and a mid drive

I need to determine wheel rpm...reliably... in order to send a a signal to a chip that switches between the two motors..


Any thoughts?

 

[Drunkskunk]

Is the hub a direct drive? if so, pull the pulses off the hall sensors, the same way the Cycle Analyst does it. There's even a pad on the board for it if your controller doesn't have a CA hookup or the blue speedo wire already.

 

[d8veh]

Any cheap bike computer sensor will do it, or you can get a hall sensor one like this:
http://www.bmsbattery.com/controller/661-s-led770-e-bike-led-meter.html

 

[bionx 1954]

If you system has a CA, you can get the RPM by setting the wheel size to 1666, chose KM, and then the speed will show RPM, eg. 35 KM = 350 RPM