Alexa Makes Home Smarter

Amazon Echo can control smart home devices (Philip Hue lights, Belkin’s WeMo switch system). But those things are pretty expensive.

If you have Infrared remote control lights (or other), this project brings these device to smart home device.

How does it work?

• Talk to Amazon Echo "Alexa, tell pi home lights on"

• Alexa Voice Service invoke Amazon Lambda function

• Lambda function update AWS IoT device shadow

• Raspberry Pi recive shadow update

• Send signal to Infrared remote control devices

Construction

Step1 - Build IR LED circuit

Connect IR reciver LED signal to GPIO 18 and IR LED to GPIO 17.

Step2 - Install and configure lirc package

sudo apt-get install lirc

Edit /boot/config.txt

# Uncomment this to enable the lirc-rpi module 
dtoverlay=lirc-rpi,gpio_in_pin=18,gpio_out_pin=17 

Reboot

sudo shutdown -r now

Check device file is created

ls  -l /dev/lirc*
crw-rw---- 1 root video 244, 0 Aug 22 23:17 /dev/lirc0

Test receiving IR remote

sudo /etc/init.d/lirc stop
mode2 -d /dev/lirc0 

Point your remote controller and push any button. If you see output like following, it means setup is good.

space 1385566
pulse 770
space 876
pulse 1590
space 874
pulse 1589
space 1681
pulse 783

Step3 - Create remote control commands

Clone sample source

cd /opt
git clone https://github.com/sparkgene/alexa_home_control.git 
cd alexa_home_control/raspberrypi 

Capture remote control signals.

sudo /etc/init.d/lirc stop
mode2 -d /dev/lirc0 | tee lights_on.txt
(enter Ctrl + C to stop capture)

Parse signal file:

python parse.py lights_on.txt
770 876 1590 874 1589 1681 783 1683 782 1680 784 1683 780 ....

Repeat this step for the button you want to use on Raspberry Pi.

Create /etc/lirc/lircd.conf and paste parsed signal. If the signal is longer than 80 characters, write it to the next line.

begin remote 
name living_light 
flags RAW_CODES 
eps            30 
aeps          100 
gap          200000  
toggle_bit_mask 0x0 
   begin raw_codes 
 name light_all 
770 876 1590 874 1589 1681 783 1683 782 1680 784  
1683 780 .... 
 name light_off 
778 875 1592 866 1600 1683 779 1713 751 865 1599  
865 1601 .... 
   end raw_codes 
end remote   

"Living_light" is the name of remote controller. If you changed this name, rewrite the `raspberrypi/iot_shadow.js ` .

https://github.com/sparkgene/alexa_home_control/blob/master/raspberrypi/iot_shadow.js#L28

sudo /etc/init.d/lirc start  
# list remote controllers  
$ irsend LIST '' ''  
irsend: living_light  
# list commands  
$ irsend LIST living_light ''  
irsend: 0000000000000001 light_all   
irsend: 0000000000000002 light_off  
# send signal  
$ irsend SEND_ONCE living_light light_all  

"light_all" and "light_off" is the name for the parsed signal. In the sample source, these name are linked with lambda function.

https://github.com/sparkgene/alexa_home_control/blob/master/alexa_home_controller/lambda_function.py#L24-L39

Test commands

If your config is correct, Raspberry Pi becomes a remote controller.

Step 4 - Setup AWS IoT

This sample only use AWS IoT device shadow. Just setup the Thing and certificate. Follow the steps in AWS document to add the thing and certificate.

http://docs.aws.amazon.com/ja_jp/iot/latest/developerguide/iot-gs.html

Do not forget to download certificates. After creating the Thing, add device shadow state.

{ 
 "desired": { 
   "command": "none", 
   "counter": 0
 } 
} 

Step 5 - Setup Amazon Lambda function

This Lambda function update AWS IoT device shadow. So attach a role which have correct permission like following.

{
   "Version": "2012-10-17", 
   "Statement": [
    { 
      "Effect": "Allow", 
      "Action": [ 
        "logs:CreateLogGroup", 
        "logs:CreateLogStream", 
        "logs:PutLogEvents" 
      ], 
      "Resource": "*" 
    }, 
    {
       "Effect": "Allow", 
       "Action": [ 
         "iot:Receive", 
         "iot:GetThingShadow", 
         "iot:UpdateThingShadow" 
       ], 
       "Resource": "*" 
    } 
  ]
} 

Create lambda function.

https://github.com/sparkgene/alexa_home_control/blob/master/alexa_home_controller/lambda_function.py

Step 6 - Setup AWS IoT client on Raspberry Pi

SSH to Raspberry Pi again. Copy certificate files which download in Step 4. Certificate file to /opt/alexa_home_control/raspberrypi/certs/certificate.pem.crt private key to /opt/alexa_home_control/raspberrypi/certs/private.pem.key

Run setup:

cd /opt/alexa_home_control/raspberrypi
sh ./setup.sh

You can see the log at /var/log/daemon.log

Step 7 - Create Alexa Skill

Add a new skill with following samples.

Skill Type:

Custom Interaction Model

Intent Schema:

https://github.com/sparkgene/alexa_home_control/blob/master/alexa_skill/intent_schema.json

Custom Slot Types

Type: LIST_OF_FAN_ACTION

Values: https://github.com/sparkgene/alexa_home_control/blob/master/alexa_skill/slot_LIST_OF_FAN_ACTION

Sample Utterances

https://github.com/sparkgene/alexa_home_control/blob/master/alexa_skill/utterances

Endpoint

Add your Lambda function ARN.

Account Linking

No

Now you can test your skill. Fix the Lambda function APP_ID variable with your skill application id before testing.

https://github.com/sparkgene/alexa_home_control/blob/master/alexa_home_controller/lambda_function.py#L7