angle sensor

salam alaykum

I have a project with a geared DC motor , I need to find the position of motor every time . I try with a pot but it is not accurate enough , I want the sensor detect the position every degree .
please if there any means rather than potentiometer to detect the angular position accurately.
thanks to anyone who is trying to help me :slight_smile:

I believe this is often done using a quadrature encoder. Essentially a photosensor that doesn't move (on the frame of your bot) and a spinning wheel with alternating black and white swatches on it. The voltage of the photosensr will indicate whether it is looking at black or white, and you can keep track of that information in the code to extrapolate position.

Can you use a stepper motor instead?

I don't believe steppers provide any feed back. If it stalls then you would not detect it.

An absolute shaft (or rotary) encoder will do what you want and will continue to read out the motor position even in the event of a power outage. You will need a 400 or 512 step encoder to have better than 1 degree accuracy. They are not cheap, though. Here is an overview of shaft encoders: Products from Parker Hannifin

jremington:
You will need a 400 or 512 step encoder to have better than 1 degree accuracy. They are not cheap, though.

Well the AMS magnetic rotary encoder chips aren't that expensive, $10 or equivalent. Some
are 10 and 12 bit. One of the german magnet suppliers has the right magnets for them.

http://www.madscientisthut.com/Shopping/agora.cgi?product=CNC%20/%20Robotic%20Sensors

you can add a gear (1-10) between shaft and rotary encoder to improve accuracy.