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
According to the data sheet the sensor is digital. It will not show voltage variation, just on and off.
I found SS49E is OK for me. How to interface it with Arduino?
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).
about programming? where can I find a library? Or should I write the code?
Use the analogRead() function to read the sensor output.
Calculate the voltage.
Subtract 2.5 from the voltage (remove the offset). Divide the result by the sensor sensitivity (0.0014 nominal, see the data sheet).
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.
According to the data sheet the sensor is digital.
How to configure this type of sensor on Arduino? It has digital current sinking output, so I expect to see only on/off behavior
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.
Since it’s a sinking output, Emitter leg must be linked to ground and Base to Digital input? Do I have to put some resistance in series?
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.