From https://github.com/loansindi/ps1rfid:

Client-side RFID authentication (and general access control) for Pumping Station: One

This system is built on a BeagleBone Black and Sparkfun's USB board for RFID readers for hardware, and PS1Auth's server-side RFID authentication on the backend.

Client-side software is written in Go.

Making things work

Cloning this repo to your BBB is the first step. The primary challenges:

• Launching application on startup of the BBB
• Enabling non-root access to the GPIO

First, you'll want to create a user to run the service. I created a user 'rfid'

$ sudo adduser rfid

Go ahead and also create a group 'gpio'

$ sudo addgroup gpio

Here's the service file I'm using to launch the application:

[Unit]
Description=Rfid entry service
After=udev.service

[Service]
Type=simple
User=rfid
group=rfid
ExecStart=/home/derek/go/src/github.com/loansindi/ps1rfid/ps1rfid
WorkingDirectory=/srv/rfid
Restart=always

[Install]
WantedBy=multi-user.target

Drop this in /etc/systemd/system/rfid.service

The udev rules go in /etc/udev/rules.d/90-gpio.rules :

KERNEL=="gpio*", SUBSYSTEM=="gpio", ACTION=="add", PROGRAM="/bin/sh -c 'chown -R rfid:gpio /sys/class/gpio'"
KERNEL=="gpio*", SUBSYSTEM=="gpio", ACTION=="add", PROGRAM="/bin/sh -c 'chown -R rfid:gpio /sys/devices/virtual/gpio/'"

This should allow non-elevated ccess to the GPIO.