Controlling mains AC or DC via Raspberry Pi via Alexa
Background
I have LED strip lights, lighting the floating wall, and want to control them via Alexa. The raspberry pi will be doing the actual switching.
There is a decent library which emulates a belkin wemo switch called fauxmo and Alexa can control Belkin's Wemo switches.
Requirements:
- Raspberry Pi (I will be using a 3 model b)
- Opto relays (I Bought mine from Amazon UK https://www.amazon.co.uk/gp/product/B06XK6HCQC/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 )
- Amazon echo or echo dot
- Wires and a breadboard
Wiring
- Install N00bs, following the raspberry pi guide here: https://www.raspberrypi.org/documentation/installation/noobs.md
- Attach everything (I am using a breadboard), according to this pinout (raspberry pi 2/3 specific)
So:
GND on the relay -> GND on the raspberry Pi
IN1,2,3,4 -> GPIO 2,3,4,17
VCC -> 5v power.
As of writing this, n00bs, has all the pre-reqs pretty much installed already, but you will need to double check, using this excellent guide from adafruit ( https://learn.adafruit.com/adafruits-raspberry-pi-lesson-4-gpio-setup/configuring-gpio )
Testing
Write some test code to check it all works (this will need to be run as root)Change the GPIO numbers according to your setup.
#!/usr/bin/python
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BCM)
# init list with pin numbers
pinList = [2, 3, 4, 20, 21]
# loop through pins and set mode and state to 'high'
for i in pinList:
GPIO.setup(i, GPIO.OUT)
GPIO.output(i, GPIO.LOW)
print i
print "ALL SET LOW"
# time to sleep between operations in the main loop
SleepTimeL =3
time.sleep(SleepTimeL);
# main loop
try:
time.sleep(SleepTimeL);
GPIO.output(2, GPIO.HIGH)
print "TWO"
time.sleep(SleepTimeL);
GPIO.output(3, GPIO.HIGH)
print "THREE"
time.sleep(SleepTimeL);
GPIO.output(4, GPIO.HIGH)
print "FOUR"
time.sleep(SleepTimeL);
GPIO.output(20, GPIO.HIGH)
print "20"
time.sleep(SleepTimeL);
GPIO.output(21, GPIO.HIGH)
print "21"
time.sleep(SleepTimeL);
print "Good bye!"
for i in pinList:
GPIO.output(i, GPIO.LOW)
# GPIO.cleanup()
# End program cleanly with keyboard
except KeyboardInterrupt:
print " Quit"
# Reset GPIO settings
GPIO.cleanup()
Alexa integration
pip install fauxmo
Check the code out in my repo: https://bitbucket.org/c240amg/raspberry-pi-alexa/src/
