11 March, 2020

A1120EUA Hall Effect Switch vs Pi Zero W

I'm building a bike-wheel LED project that wants to know how fast the wheel is turning, and what position it is in as it spins.
Got A1120EUA-T from hobbytronics
turns out you can't set pullups from sysfs (/sys/class/gpio) ... so i'll have to install wiringpi for the gpio command.
$ gpio export 0 in
$ gpio mode 0 up

and now I can wave my neodymium magnets nearby (about 1.5cm) and see the input go low as it passes by.
$ while true; do gpio read 0 ; done
1
1
1
0