ikenna ijeh

Important changes to forums and questions

All forums and questions are now archived. To start a new conversation or read the latest updates go to forums.mbed.com.

8 years, 9 months ago.

A Compatible steering (rotational) sensor

what sensor can one use to detect the steering position of the steering wheel while using an mbed.

3 Answers

Zoltan Hudak
8 years, 9 months ago.

Hi Ikenna,

Provided that ±45° is sufficient for your application then you could also use an affordable HMC1501 Linear / Angular / Rotary Displacement Sensor:

  • Angular range of ±45° with <0.07° resolution.
  • Full Scale output range of 120mV (+/-60mV at a small offset) with 5V of power supply.
  • Unlike incremental encoding devices, sensor knows the exact position and requires no indexing for proper positional output.
  • No moving parts to wear out; no dropped signals from worn tracks as in conventional contact based rotary sensors.

If you use the HMC1501 with 3.3V power supply then the differential output becomes +/-40mV which fits into 'channel B' of differential input of an affordable HX711 24-Bit Analog-to-Digital Converter (designed for Weigh Scales) with 3.3V power suppy. Since the HX711 is already supported by several mbed user libraries (like for example this one) you'll get an mbed compatible steering sensor.

In case you need to cover a wider range (>±45°) then you can use a combination of HMC1501 sensors or an HMC1512 sensor.

Accepted Answer
David Fletcher
8 years, 9 months ago.

One option would be to use a rotary encoder.

Gary Z
8 years, 9 months ago.

another option is to get a good quality LINEAR potentiometer. connected to the AD input Audio pots are not linear. find an exposed portion of the steering wheel shaft and put (rubber ?) belt around it and the shaft of the Pot OR rotary encoder. "" another option might be to use a wheel to turn the ball of a mouse , then count the 'clicks' [this requires the older fashion mouse.] You could make a slotted plate onto the wheel and use an optical interrupter- this is what the original mice used. '' put a reflective tape with a pattern on it and 'read' it with an opto reader. a gray code or binary code pattern could be put on several strips next to each other to get a fine granule reading.