chinadev / go-rpio

:electric_plug: Raspberry Pi GPIO library for go-lang

go-rpio

Native GPIO-Gophers for your Pi!

go-rpio is a Go library for accessing GPIO-pins on the Raspberry Pi.

It requires no external c libraries such as WiringPI or bcm2835.

There's a tiny bit of additional information over at my blog.

Releases

• 1.0.0 - Supports original rpi A/B/B+
• 2.0.0 - Adds support for rpi 2, by @akramer
• 3.0.0 - Add support for /dev/gpiomem, by @dotdoom

Usage

import "github.com/stianeikeland/go-rpio"

Open memory range for GPIO access in /dev/mem

err := rpio.Open()

Initialize a pin, run basic operations. Pin refers to the bcm2835 pin, not the physical pin on the raspberry pi header. Pin 10 here is exposed on the pin header as physical pin 19.

pin := rpio.Pin(10)

pin.Output()       // Output mode
pin.High()         // Set pin High
pin.Low()          // Set pin Low
pin.Toggle()       // Toggle pin (Low -> High -> Low)

pin.Input()        // Input mode
res := pin.Read()  // Read state from pin (High / Low)

pin.Mode(rpio.Output)   // Alternative syntax
pin.Write(rpio.High)    // Alternative syntax

Pull up/down/off can be set using:

pin.PullUp()
pin.PullDown()
pin.PullOff()

pin.Pull(rpio.PullUp)

Unmap memory when done

rpio.Close()

Also see example examples/blinker/blinker.go

Other

Currently, it supports basic functionality such as:

• Pin Direction (Input / Output)
• Write (High / Low)
• Read (High / Low)
• Pull (Up / Down / Off)

Would be nice to add in the future:

• PWM
• I2C
• SPI
• etc...

It works by memory-mapping the bcm2835 gpio range, and therefore require root/administrative-rights to run.

Using without root

This library can utilize the new /dev/gpiomem memory range if available.

You will probably need to upgrade to the latest kernel (or wait for the next raspbian release) if you're missing /dev/gpiomem. You will also need to add a gpio group, add your user to the group, and then set up udev rules. I would recommend using create_gpio_user_permissions.py if you're unsure how to do this.