Saturday, 29 July 2017

Hall sensor array quick post

Just a quick post in response to a couple of questions we've been getting for a schematic for a hall sensor array, being driven directly off the Arduino i/o pins.

If you place your A3144 hall sensors in a grid pattern, with the "flat" part of the sensor facing down (with the slightly bevelled face pointing upwards) then all of the centre pins should be connected together (a common ground).

Each of the left-hand pins should be connected horizontally to the sensors immediately left/right of them. Each of the right hand pins should be connected vertically to the sensors immediately above/below them.

The left-hand pins are the power supply for the sensors.
The right hand pins are the open-drain collectors (outputs) of the sensors.

We try to put the output pins (from the sensors) on our Arduino D2-D9 pins and make them inputs with interal pullups. We try to connect the output pins to power the sensors onto the Arduino D10-D17 pins and make them outputs, because D13 usually has an LED connected to it - you can still power a hall sensor from this pin, but using D13 as an input can be problematic.

Hope this clears a few questions up!