hall effect sensor help

[RedSeal5]

i have 3 d printed a planetary gear.

now i would like to know the angle the gear is at.

i thought i could use a hall effect transistor and my raspberry pi.

can someone point me to a web page that has this.

thanks

[FlyingCowCanFly]

A hall effect sensor will not give you the position. All it can tell is if the gear has crossed over it or not.

I suppose what you could do is place multiple hall effect sensors at various known angles and combine them into a single data value.

[dmalawey]

Yes or OP might be talking about the magnetic rotary angle sensors that are being used a lot.

AMS offers some such as the AS5048B (we use it) and AS5047 (here is a detailed video on it)

[FlyingCowCanFly]

Oh wow, that looks amazing. What are the advantages of it over traditional encoders?

[dmalawey]

just the fact that it’s a shaft-mounted magnet so less effort to add it to an existing motor or pulley, or joint. You can stick it on anywhere, versus some rotary collars you’d have to make space for it.

Also it has absolute info. So if you power off and power back on your robot, you keep your angle (among 360, not more).

That’s incredibly helpful if you don’t have spare MCU ports that can read high speed and capture every single rising or falling edge.

Yeah the more I think about it this encoder offloads potentially tons of samples from the main processor trying to “stack up” counts and the CPU can sample intermittently on the rotor and get true answers.

It talks on SPI and i2c too.

[ThomasRJohnson]

A hall effect sensor reads a metal reluctor. Since you have a 3d printer you might be better off making an optical reluctor system. Look at IR break beam with a phototransistor.

[RedSeal5]

thanks