gpiopwm

README

GPIO PWM activity

This activity allows you control PWM pins of a Raspberry Pi.

WARNING: The GPIO PWM activity requires that flogo runs as root.

Installation

Flogo Web

Start

Start a container of Flogo Web UI :

docker run --name flogo -it -d -p 3303:3303 -e FLOGO_NO_ENGINE_RECREATION=false flogo/flogo-docker eula-accept

The environment variable FLOGO_NO_ENGINE_RECREATION=false allows to force import of installed contributions.

Installation of the activity

To install the activity into the started container :

docker exec -it flogo sh -c 'cd /tmp/flogo-web/build/server/local/engines/flogo-web && flogo install github.com/square-it/flogo-contrib-activities/gpiopwm'

Restart the container

docker restart flogo

Flogo CLI

flogo install github.com/square-it/flogo-contrib-activities/gpiopwm

Schema

Inputs and Outputs:

{
 "inputs":[
    {
      "name": "pinNumber",
      "type": "int",
      "required": true,
      "allowed": [12, 13, 18, 19, 40, 41, 45]
    },
    {
      "name": "pwmFrequency",
      "type": "int",
      "required": true
    },
    {
      "name": "dutyLength",
      "type": "uint32",
      "required": true
    },
    {
      "name": "cycleLength",
      "type": "uint32",
      "required": true
    }
  ],
  "outputs": [
  ]
 }

Settings

Setting	Required	Description
pinNumber	True	The index of the pin of the GPIO header to modify
pwmFrequency	True	The frequency (in Hz) of the PWM
dutyLength	True	The duty part of the duty cycle
cycleLength	True	The cycle part of the duty cycle

See https://godoc.org/github.com/stianeikeland/go-rpio#SetDutyCycle for more details about Duty and Cycle.

Outputs

Output	Description

Examples

Activate PWM with 1ms duty and 50Hz frequency on pin 12

{
  "id": "gpiopwm_1",
  "name": "GPIO PWM",
  "description": "Perform PWM control on Raspberry GPIO. Requires root access.",
  "activity": {
    "ref": "github.com/square-it/flogo-contrib-activities/command",
    "input": {
      "pinNumber": 12,
      "pwmFrequency": 50,
      "dutyLength": 100,
      "cycleLength": 2000
    },
    "output": {
    }
  }
}

Disable PWM on pin 12 (set dutyLength to 0)

{
  "id": "gpiopwm_1",
  "name": "GPIO PWM",
  "description": "Perform PWM control on Raspberry GPIO. Requires root access.",
  "activity": {
    "ref": "github.com/square-it/flogo-contrib-activities/command",
    "input": {
      "pinNumber": 12,
      "pwmFrequency": 50,
      "dutyLength": 0,
      "cycleLength": 2000
    },
    "output": {
    }
  }
}

Documentation

Index

• func NewActivity(metadata *activity.Metadata) activity.Activity
• type Activity
  • func (a *Activity) Eval(context activity.Context) (done bool, err error)
  • func (a *Activity) Metadata() *activity.Metadata

Functions

func NewActivity

func NewActivity(metadata *activity.Metadata) activity.Activity

NewActivity creates a new activity

Types

type Activity

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

func (*Activity) Eval

func (a *Activity) Eval(context activity.Context) (done bool, err error)

Enable PWM, then set Frequency and DutyCycle on the given GPIO pin

func (*Activity) Metadata

func (a *Activity) Metadata() *activity.Metadata

Metadata implements activity.Activity.Metadata