Raspberry π

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pascalo

I built myself a garage door opener with an old raspberry pi and a two switch relay wired up to the roller door motors that have an external switch port.
Custom Android app to set off AWS lambda call to SNS to SQS, which a little process on the pi consumes and uses the GPIO port to trigger the relays. Takes a pic of before and after via webcam, uploads to s3, so I can view that in the app, too.

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cyclotron3k in reply to @pascalo

Neato! Are the relays wired directly to the gpio pins? Did you have to worry about current drain and flyback diodes?

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pascalo in reply to @cyclotron3k

Yep, just wired directly to it via jumper cables.
I didn't worry about any of that, nope.

This is the relay I used:

https://www.sainsmart.com/products/2-channel-5v-relay-module

Python side:

import boto3
from time import sleep

import json
import sys
import traceback
import RPi.GPIO as GPIO
from time import sleep

import datetime as dt

from subprocess import call


# Set up SQS
sqs = boto3.resource('sqs')
queue = sqs.Queue('QUEUE_URI')

# Set up S3
s3 = boto3.resource('s3');

# Set up GPIO
GPIO.setmode(GPIO.BCM)

GPIO.setup(24, GPIO.OUT)
GPIO.output(24, GPIO.HIGH)

GPIO.setup(25, GPIO.OUT)
GPIO.output(25, GPIO.HIGH)


def takeAndStorePicture(name):
    call(['fswebcam', '-q', '--rotate', '180', '-r', '640x360', '--jpeg', '80', '--timestamp', '%D %T (%Z)', name])
    obj = s3.Object('BUCKET_NAME', name).upload_file(name, ExtraArgs={
        'ACL': 'public-read'
    })


def relayOnOff(side):

    if side == 'left':
        channel = 24

    if side == 'right':
        channel = 25

    GPIO.output(channel, GPIO.LOW)
    sleep(1)
    GPIO.output(channel, GPIO.HIGH)


def main():
    try:

       while(True):
            messages = queue.receive_messages()

            for message in messages:
                 print 'Message: ' + message.body
                 j = json.loads(message.body)
                 takeAndStorePicture('before.jpg')
                 relayOnOff(j['Message'])
                 message.delete()
                 sleep(10)
                 takeAndStorePicture('after.jpg')

            sleep(1)

    except KeyboardInterrupt:
        print "Shutdown requested...exiting"

    except Exception:
        traceback.print_exc(file=sys.stdout)

    GPIO.cleanup();
    sys.exit(0)

if __name__ == "__main__":
    main()

Raspberry π

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