I would like to do some tests with a magnet and a Hall effect sensor (Honeywell SS411A).
Is it possible to interface them in your opinion? I would go and pin the terminals on the white board but I do not know if we need resistances in series, etc...
I would simply like to read the voltage variation depending on the distance from the magnet
V+ of the sensor to Vcc of your Arduino, V- of the sensor to ground of the Arduino and the output from the sensor to an analog input on the Arduino.
On a 5.0V Arduino and in the absence of a magnetic field (0 Gauss) the output will be 1/2 Vcc (2.5V) and will range from 1V (-1000 Gauss) to 4V (1000 Gauss).
It has an open collector output that is used for switching.
Normally, you would would have a positive voltage and a resistor connected to the collector of an NPN transistor, the data pin. Depending on the actual setup in the data sheet, you will get either the positive voltage (HIGH) at the resistor/collector junction, or Ground (LOW) which you easily see with a meter.
The data pin would connect to a digital input on the Arduino..
This type of Hall sensor is generally used for position sensing like measuring the RPM of a wheel.
Connect V+ to Vcc, gnd to ground and the output to a digital input set to pinMode INPUT_PULLUP. The input will read LOW in the presence of a magnetic field HIGH when not.
The required resistor is a pull-up resistor because the output is open collector. That is taken care of by the internal pullup if you set the input pin pinMode to INPUT_PULLUP.