Using a HMC5883L as proximity sensor

Other Hardware Sensors
1

Hi

I would like to make a fairly sensitive magnet sensor (range around 300mm with magnet in any orientation) and have tried a 2SS52M which could only manage around 50mm depending on size and orientation of the magnet. (10mm neodymium cube). I think most hall effect sensors would manage less than that?

So I am wondering if the high sensitivity magnetoresistor in the HMC5883L would work? As they aim to filter out higher field strengths which would normally be problematic in its use as a compass I am not sure.

Just wondering if anyone has used a HMC5883L and found it to be sensitive to the presence of magnets?

The only logic is if the magnet is sensed or not - no other data required.

Or is there another (cheap) way to achieve this reasonable distance proximity sensing with the item to be sensed being passive and smaller than say a 30mm cube? (My first preference would be RF, but I can't find anything that meets these criteria without looking at specialist and expensive equipment).

Thanks.

2

Yes, the HMC5883L is extremely sensitive to magnets, or the presence of iron-containing or other magnetic materials. I use a similar magnetometer as a vehicle detector at the gate to our property.

If a magnet comes too close, the sensor may become saturated and semi-permanently, or even permanently lock up. You will have to experiment.