raspi

README

Raspberry Pi

The Raspberry Pi is an inexpensive and popular ARM based single board computer with digital & PWM GPIO, and i2c interfaces built in.

The Gobot adaptor for the Raspberry Pi should support all of the various Raspberry Pi boards such as the Raspberry Pi 3 Model B, Raspberry Pi 2 Model B, Raspberry Pi 1 Model A+, Raspberry Pi Zero, and Raspberry Pi Zero W.

For more info about the Raspberry Pi platform, click here.

How to Install

We recommend updating to the latest Raspian Jessie OS when using the Raspberry Pi, however Gobot should also support older versions of the OS, should your application require this.

You would normally install Go and Gobot on your workstation. Once installed, cross compile your program on your workstation, transfer the final executable to your Raspberry Pi, and run the program on the Raspberry Pi as documented here.

go get -d -u gobot.io/x/gobot/...

How to Use

The pin numbering used by your Gobot program should match the way your board is labeled right on the board itself.

package main

import (
        "time"

        "gobot.io/x/gobot"
        "gobot.io/x/gobot/drivers/gpio"
        "gobot.io/x/gobot/platforms/raspi"
)

func main() {
        r := raspi.NewAdaptor()
        led := gpio.NewLedDriver(r, "7")

        work := func() {
                gobot.Every(1*time.Second, func() {
                        led.Toggle()
                })
        }

        robot := gobot.NewRobot("blinkBot",
                []gobot.Connection{r},
                []gobot.Device{led},
                work,
        )

        robot.Start()
}

How to Connect

Compiling

Compile your Gobot program on your workstation like this:

$ GOARM=6 GOARCH=arm GOOS=linux go build examples/raspi_blink.go

Use the following GOARM values to compile depending on which model Raspberry Pi you are using:

GOARM=6 (Raspberry Pi A, A+, B, B+, Zero) GOARM=7 (Raspberry Pi 2, 3)

Once you have compiled your code, you can upload your program and execute it on the Raspberry Pi from your workstation using the scp and ssh commands like this:

$ scp raspi_blink pi@192.168.1.xxx:/home/pi/
$ ssh -t pi@192.168.1.xxx "./raspi_blink"

Enabling PWM output on GPIO pins.

For extended PWM support on the Raspberry Pi, you will need to use a program called pi-blaster. You can follow the instructions for pi-blaster install in the pi-blaster repo here:

https://github.com/sarfata/pi-blaster

Documentation

Overview

Package raspi contains the Gobot adaptor for the Raspberry Pi.

For further information refer to raspi README: https://github.com/hybridgroup/gobot/blob/master/platforms/raspi/README.md

Index

• type Adaptor
  • func NewAdaptor() *Adaptor
  • func (r *Adaptor) Connect() (err error)
  • func (r *Adaptor) DigitalPin(pin string, dir string) (sysfsPin sysfs.DigitalPinner, err error)
  • func (r *Adaptor) DigitalRead(pin string) (val int, err error)
  • func (r *Adaptor) DigitalWrite(pin string, val byte) (err error)
  • func (r *Adaptor) Finalize() (err error)
  • func (r *Adaptor) GetConnection(address int, bus int) (connection i2c.Connection, err error)
  • func (r *Adaptor) GetDefaultBus() int
  • func (r *Adaptor) Name() string
  • func (r *Adaptor) PWMPin(pin string) (raspiPWMPin sysfs.PWMPinner, err error)
  • func (r *Adaptor) PwmWrite(pin string, val byte) (err error)
  • func (r *Adaptor) ServoWrite(pin string, angle byte) (err error)
  • func (r *Adaptor) SetName(n string)
• type PWMPin
  • func NewPWMPin(pin string) *PWMPin
  • func (p *PWMPin) DutyCycle() (duty uint32, err error)
  • func (p *PWMPin) Enable(e bool) (err error)
  • func (p *PWMPin) Export() error
  • func (p *PWMPin) InvertPolarity(invert bool) (err error)
  • func (p *PWMPin) Period() (period uint32, err error)
  • func (p *PWMPin) Polarity() (polarity string, err error)
  • func (p *PWMPin) SetDutyCycle(duty uint32) (err error)
  • func (p *PWMPin) SetPeriod(period uint32) (err error)
  • func (p *PWMPin) Unexport() error

Types

type Adaptor

type Adaptor struct {
	// contains filtered or unexported fields
}

Adaptor is the Gobot Adaptor for the Raspberry Pi

func NewAdaptor

func NewAdaptor() *Adaptor

NewAdaptor creates a Raspi Adaptor

func (*Adaptor) Connect

func (r *Adaptor) Connect() (err error)

Connect starts connection with board and creates digitalPins and pwmPins adaptor maps

func (*Adaptor) DigitalPin

func (r *Adaptor) DigitalPin(pin string, dir string) (sysfsPin sysfs.DigitalPinner, err error)

DigitalPin returns matched digitalPin for specified values

func (*Adaptor) DigitalRead

func (r *Adaptor) DigitalRead(pin string) (val int, err error)

DigitalRead reads digital value from pin

func (*Adaptor) DigitalWrite

func (r *Adaptor) DigitalWrite(pin string, val byte) (err error)

DigitalWrite writes digital value to specified pin

func (*Adaptor) Finalize

func (r *Adaptor) Finalize() (err error)

Finalize closes connection to board and pins

func (*Adaptor) GetConnection

func (r *Adaptor) GetConnection(address int, bus int) (connection i2c.Connection, err error)

GetConnection returns an i2c connection to a device on a specified bus. Valid bus number is [0..1] which corresponds to /dev/i2c-0 through /dev/i2c-1.

func (*Adaptor) GetDefaultBus

func (r *Adaptor) GetDefaultBus() int

GetDefaultBus returns the default i2c bus for this platform

func (*Adaptor) Name

func (r *Adaptor) Name() string

Name returns the Adaptor's name

func (*Adaptor) PWMPin

func (r *Adaptor) PWMPin(pin string) (raspiPWMPin sysfs.PWMPinner, err error)

PWMPin returns a raspi.PWMPin which provides the sysfs.PWMPinner interface

func (*Adaptor) PwmWrite

func (r *Adaptor) PwmWrite(pin string, val byte) (err error)

PwmWrite writes a PWM signal to the specified pin

func (*Adaptor) ServoWrite

func (r *Adaptor) ServoWrite(pin string, angle byte) (err error)

ServoWrite writes a servo signal to the specified pin

func (*Adaptor) SetName

func (r *Adaptor) SetName(n string)

SetName sets the Adaptor's name

type PWMPin

type PWMPin struct {
	// contains filtered or unexported fields
}

PWMPin is the Raspberry Pi implementation of the PWMPinner interface. It uses Pi Blaster.

func NewPWMPin

func NewPWMPin(pin string) *PWMPin

NewPwmPin returns a new PWMPin

func (*PWMPin) DutyCycle

func (p *PWMPin) DutyCycle() (duty uint32, err error)

DutyCycle returns the duty cycle for the pin

func (*PWMPin) Enable

func (p *PWMPin) Enable(e bool) (err error)

Enable enables/disables the PWM pin

func (*PWMPin) Export

func (p *PWMPin) Export() error

Export exports the pin for use by the Raspberry Pi

func (*PWMPin) InvertPolarity

func (p *PWMPin) InvertPolarity(invert bool) (err error)

InvertPolarity does not do anything when using PiBlaster

func (*PWMPin) Period

func (p *PWMPin) Period() (period uint32, err error)

Period returns the current PWM period for pin

func (*PWMPin) Polarity

func (p *PWMPin) Polarity() (polarity string, err error)

Polarity returns the polarity either normal or inverted

func (*PWMPin) SetDutyCycle

func (p *PWMPin) SetDutyCycle(duty uint32) (err error)

SetDutyCycle writes the duty cycle to the pin

func (*PWMPin) SetPeriod

func (p *PWMPin) SetPeriod(period uint32) (err error)

SetPeriod does not do anything when using PiBlaster

func (*PWMPin) Unexport

func (p *PWMPin) Unexport() error

Unexport unexports the pin and releases the pin from the operating system