Hall Effect Sensor

Other Hardware Sensors
1

So my hall effect sensor, plugged into my A0 pin reads 510ish for when no magnet is present and this is correct as per the datasheet: for 0 guass, 2.5V is seen.

Earlier, before packing up my project and unpacking it now, I had it working so that this 510 analogRead was 0, because that is what I want. I want it to read 0 at 2.5V.

I cant remember changing anything and now I cant figure out how to make this 2.5V my required 0V reading on my analogRead.

Please help.

This is because the sensor uses 144 of the 1023 available and I made a voltage divider to increase this 144 (0.7Vish) resolution to the full 1023.

But I cant remember how I made the 2.5V read 0 on analog read. :frowning:

2

I used the external analogue reference to the voltage divider to create this increased resolution.

But for the life of my I cant remember how I got 0 on analogRead with no magnet present.