Hall effect magnetic field sensor will detect the presence of nearby magnets.
Its electric signal is amplified by an IC which can provides a digital and an analog
output for further processing.
Board connections:
Vcc: 3.3V to 5V
GND: Negative terminal of battery
DO: Digital output, max. current 16ma. ( goes low when magnetic
field is detected)
AO: Analog output (varies with the intensity of magnetic field)
Dimensions: 32 x 14mm
Mounting holes: 3mm
Power indicator: LED
Price: $1.50