I am working on a precision position project and I am looking for advice regarding the selection of a Hall Effect Sensor. The sensor will be placed anywhere from 0.5 to 1 cm away from a magnet with a north and a south pole. When the sensor is moved over either pole I need it to send a signal to the Arduino Mega 2560 for processing prior to sending a signal to the actuator. I plan to power the sensor from the 5V supply of the board. I am pretty new to sensors and circuits.
What I am looking for:
Small and Compact
Sensing from 0.5 to 1 cm away
Sensing from 0 to 10,000 Gauss
-Is there any advantage of digital vs. analog sensors? I think I will go with digital because I care about north or south poles, and a magnitude of 0.
-I found a few sensor for precision measurement but they were expensive (over 200 USD). Is it possible to use a more affordable sensor since it will be positioned so close the magnet it needs to read?
The analog hall sensors can also sense North and South.
An analog sensor is easier to start with, you don't have to communicate with the sensor.
For accurate temperatures (DS18B20) or baromic pressure (BMP085) I would advice a digital sensor. It is far more accurate. But to only detect something, analog is easier.
Some hall 'sensors' are hall switches. They switch the output at a certain level.
These are switches:
If you want to measure the level and also North and South, those are often ratiometric or linear.
They are 4 dollars for 10 of them on Ebay.
You have to read the datasheets to see if they have the range you need.
I think I have decided on this sensor, I just want to confirm it will perform inline with my requirements. The range of the magnetic field I need to sense is -180 to +180. The range is -650 to +650 Gauss. At maximum the sensor may be exposed to 9000 Gauss.
Is it correct that if exposed to a magnetic field greater than it's specified range that the sensor will become saturated rather than damaged? Will it become unsaturated instantly once exposed to a magnetic field within it's range again?
According to the data sheet I should have no issue powering this from the Arduino 5V pin right?
How do you know which orientation to use for your sensor? Trial and error?