Another blog about home automation. We added Somfy IO motorized rolling shutters to our house recently with a Situo 5 IO remote to control them. But what about controlling these rolling shutters with a Raspberry Pi, preferably without an expensive hub? I did some tinkering and found a much cheaper solution.

Somfy IO or RTS

Somfy uses two types of wireless control for motorized rolling shutters: RTS and io-homecontrol. RTS stands for Radio Technology Somfy and uses the open 433 MHz radiofrequency for one-way control. Io-homecontrol is the newer two-way wireless technology. This technology is more secure and more reliable, but this also means that it is more difficult to control with products like a Raspberry Pi.

If you have rolling shutters with an RTS wireless receiver you should look for blogs about Raspberry Pi and rf433. This blog is about controlling Somfy IO rolling shutters with a Raspberry Pi. This solution won’t work with RTS rolling shutters.

What do you need?

Well, Somfy motorized rolling shutters and a Raspberry Pi of course. But what else? You’ll find a small shopping list below.

Do you need a hub?

Somfy offers two devices for smart home control of their rolling shutters: the TaHoma hub and the Connexoon io hub. The TaHoma costs about 300 euro and the Connexoon about 170 euro. That’s quite expensive! I already use a Raspberry Pi to control most of my smart home devices and I don’t want to add another hub just to move my rolling shutters. I want to control my rolling shutters without a hub.

Other requirements

I did some Google searches and I found the Somfy Izymo transmitter module. This module is meant for people who already have a wired push-button or rocker switch that they want to transform into an io control. When I got this module it cost about 35 euro, but the price has gone up a bit to about 50 euro.

As you’ll see below, you’ll also need a relay with at least two channels. I used this two-channel relay that cost 6,95 euro.

And finally, you’ll need some wires to connect the Raspberry Pi, the Izymo module, and the relay. You could also use a breadboard or a small terminal block to make connections without soldering. This shouldn’t cost much. I had this stuff lying around from other projects.

You’ll also need a remote to pair the Izymo transmitter to the rolling shutters. You’ll only need to do this once and you can still use the remote like a regular remote afterward.

So here’s your shopping list:

Even cheaper option

During my search for a solution, I also found some blogs about soldering a Somfy remote directly to an Arduino or a Raspberry Pi. Since a single remote is a bit cheaper than the Izymo module this option will be a bit cheaper altogether. I did not choose this option, because I don’t want to butcher a remote for this. But it is an option.

Pairing the transmitter

Before you can use the Izymo transmitter it must be paired with the rolling shutters. The easiest way is to use another remote that is already paired with the rolling shutters. There’s a small button on the back of the Situo 5 IO remote that can be used to put the rolling shutters in association mode. Then briefly press the PROG 1 button (for channel S1) or PROG 2 button (for channel S2) on the transmitter and that should be it.

Wiring schematics

As you can see in the picture, the Izymo module has three wires: green, white, and yellow. If you connect the white wire to the yellow wire, the rolling shutters go up. And if you connect the white wire to the green wire, the rolling shutters go down. So to control the rolling shutters, you need to physically ‘switch’ between these wires. That’s what we’ll use the relay for that was mentioned earlier.

The relay has four pins to connect it to the Raspberry Pi. On the relay I got, the VCC pin is connected to 5 volts, the GND pin is connected to ground and the other two pins (IN1 and IN2) are connected to the GPIO pins. In my case, I used pin 13 and 26 as GPIO pins, but feel free to use other pins if that suits your project.

A Python code example

After connecting all the wires we can start writing some code. There are plenty of blogs about using the GPIO pins on a Raspberry Pi with Python. I can recommend this blog if this is your first project: https://pythonprogramming.net/gpio-raspberry-pi-tutorials/. The code below is actually not very different from the example in the other blog.

You can change the pin numbers to correspond with your own project. Then call the function move_shutters() with a direction (‘up’ or ‘down’) and the duration in seconds that you want to move the rolling shutters.

In [ ]:

import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BCM)

pin_up = 26
pin_down = 13

GPIO.setup(pin_up, GPIO.OUT)
GPIO.setup(pin_down, GPIO.OUT)

GPIO.output(pin_up, GPIO.LOW)
GPIO.output(pin_down, GPIO.LOW)

def move_shutters (direction, sec):
    if (direction == 'up'):
        GPIO.output(pin_up, GPIO.HIGH)
        time.sleep(sec)
        GPIO.output(pin_up, GPIO.LOW)
    if (direction == 'down'):
        GPIO.output(pin_down, GPIO.HIGH)
        time.sleep(sec)
        GPIO.output(pin_down, GPIO.LOW)

move_shutters('down', 20)

A Nodejs example

The example below is a bit more elaborate. This is what I actually use in my own home automation project. It creates a Router for a Nodejs Express app. I also added some lines to make it work on devices without GPIO pins for testing purposes.

Google recently released its Device Access API. This article is a short explanation of how to access and use this API to control a Google Nest thermostat.

We moved to a new house a few months ago and the previous owners left their thermostat behind. This thermostat turned out to be a brand new Nest smart thermostat. Of course, I wanted to connect this smart device to my home automation. But unfortunately, after some searching, I found out that most connections were deprecated after Google acquired Nest a couple of years ago, along with the API access for consumers. The only option was to sign up for a waitlist.

But to my surprise, I got an email from Google a couple of weeks ago! The Device Access Console is now available to individual consumers as well as commercial partners. I wanted to find out if I could control my Google Nest thermostat so I wrote some Python code for this.

Get started with Google documentation

Google has written some quite elaborate documentation about all the steps needed to access the API. The purpose of this article is not to rewrite their help articles. These articles will get you started:

And you’ll also need these links:

How much does it cost?

Before creating your first project, you must pay a one-time, non-refundable fee (US$5) per account. There can also be cost involved by using Google Cloud services, but I have been polling my thermostat every 5 minutes for a couple of weeks now without cost.

Gather all requirements

It’s tempting to begin creating a Device Access project right away (I did so too), but I found out that it is probably easier to get all the necessary prerequisites first. Before you can start coding you should follow these steps:

Create a Google Cloud Console project at console.cloud.google.com
1. Create Cloud Console oAuth 2.0 credentials
2. Set a redirect URI
3. Turn on the Smart Device Access API
Create a Device Access project at console.nest.google.com

I made some screenshots from each step:

After creating an OAuth 2.0 client ID and a Device Access project you should have these values:

A project ID. You can find this in your Device Access console.
A client ID. You can find this with your OAuth credentials.
A client secret. You can find this with your OAuth credentials.
A redirect URI. This URI can be almost any URL you want, as long as this URL matches a URI that is entered as an authorized redirect URI in your Cloud Console project.

Some example API calls with Python

Now we can start making API calls! Below is a Jupyter Notebook that walks through all the steps to control a Nest thermostat.

You can also make a copy of the Google Colab notebook I made.

Example for making Nest API calls¶

Please start by making a copy of this notebook.

Enter your credentials¶

Enter your credentials and run the cell to generate a login URL. Click the URL and log in to your Google account.

In [ ]:

project_id = 'your-project-id'
client_id = 'your-client-id.apps.googleusercontent.com'
client_secret = 'your-client-secret'
redirect_uri = 'https://www.google.com'

url = 'https://nestservices.google.com/partnerconnections/'+project_id+'/auth?redirect_uri='+redirect_uri+'&access_type=offline&prompt=consent&client_id='+client_id+'&response_type=code&scope=https://www.googleapis.com/auth/sdm.service'
print("Go to this URL to log in:")
print(url)

After logging in you are sent to URL you specified as redirect_url. Google added a query to end that looks like this: ?code=.....&scope=... Copy the part between code= and &scope= and add it below:

In [ ]:

code = '4/add-your-code-here'

Get tokens¶

Now we can use this code to retrieve an access token and a refresh token:

In [ ]:

# Get tokens

import requests

params = (
    ('client_id', client_id),
    ('client_secret', client_secret),
    ('code', code),
    ('grant_type', 'authorization_code'),
    ('redirect_uri', redirect_uri),
)

response = requests.post('https://www.googleapis.com/oauth2/v4/token', params=params)

response_json = response.json()
access_token = response_json['token_type'] + ' ' + str(response_json['access_token'])
print('Access token: ' + access_token)
refresh_token = response_json['refresh_token']
print('Refresh token: ' + refresh_token)

Refresh access token¶

The access token is only valid for 60 minutes. You can use the refresh token to renew it.

In [ ]:

# Refresh token

params = (
    ('client_id', client_id),
    ('client_secret', client_secret),
    ('refresh_token', refresh_token),
    ('grant_type', 'refresh_token'),
)

response = requests.post('https://www.googleapis.com/oauth2/v4/token', params=params)

response_json = response.json()
access_token = response_json['token_type'] + ' ' + response_json['access_token']
print('Access token: ' + access_token)

Get structures and devices¶

Now lets get some information about what devices we have access to and where these are "located". Devices are part of a structure (such as your home). We can get information about the structures we have access to:

In [ ]:

# Get structures

url_structures = 'https://smartdevicemanagement.googleapis.com/v1/enterprises/' + project_id + '/structures'

headers = {
    'Content-Type': 'application/json',
    'Authorization': access_token,
}

response = requests.get(url_structures, headers=headers)

print(response.json())

But we can also directly retrieve the devices we have access to:

In [ ]:

# Get devices

url_get_devices = 'https://smartdevicemanagement.googleapis.com/v1/enterprises/' + project_id + '/devices'

headers = {
    'Content-Type': 'application/json',
    'Authorization': access_token,
}

response = requests.get(url_get_devices, headers=headers)

print(response.json())

response_json = response.json()
device_0_name = response_json['devices'][0]['name']
print(device_0_name)

Get device stats¶

For this example I simply took the first item of the array of devices. I assume most people probably have one Nest thermostat anyway.

The name of a device can be used to retrieve data from this device and to send commands to it. Lets get soms stats first:

In [ ]:

# Get device stats

url_get_device = 'https://smartdevicemanagement.googleapis.com/v1/' + device_0_name

headers = {
    'Content-Type': 'application/json',
    'Authorization': access_token,
}

response = requests.get(url_get_device, headers=headers)

response_json = response.json()
humidity = response_json['traits']['sdm.devices.traits.Humidity']['ambientHumidityPercent']
print('Humidity:', humidity)
temperature = response_json['traits']['sdm.devices.traits.Temperature']['ambientTemperatureCelsius']
print('Temperature:', temperature)

Set thermostat to HEAT¶

And last but not least, lets send some commands to our thermostat. The cell below contains the code to set the mode to "HEAT":

In [ ]:

# Set mode to "HEAT"

url_set_mode = 'https://smartdevicemanagement.googleapis.com/v1/' + device_0_name + ':executeCommand'

headers = {
    'Content-Type': 'application/json',
    'Authorization': access_token,
}

data = '{ "command" : "sdm.devices.commands.ThermostatMode.SetMode", "params" : { "mode" : "HEAT" } }'

response = requests.post(url_set_mode, headers=headers, data=data)

print(response.json())

Set a new temperature¶

And finally we can set a temperature by executing this command:

In [ ]:

set_temp_to = 21.0

In [ ]:

# Set temperature to set_temp_to degrees

url_set_mode = 'https://smartdevicemanagement.googleapis.com/v1/' + device_0_name + ':executeCommand'

headers = {
    'Content-Type': 'application/json',
    'Authorization': access_token,
}

data = '{"command" : "sdm.devices.commands.ThermostatTemperatureSetpoint.SetHeat", "params" : {"heatCelsius" : ' + str(set_temp_to) + '} }'

response = requests.post(url_set_mode, headers=headers, data=data)

print(response.json())

Category: Home automation

How to control Somfy IO with a Raspberry Pi

Somfy IO or RTS

What do you need?

Do you need a hub?

Other requirements

Even cheaper option

Pairing the transmitter

Wiring schematics

A Python code example

A Nodejs example

Controlling a Google Nest thermostat with Python

Get started with Google documentation

How much does it cost?

Gather all requirements

Some example API calls with Python

Example for making Nest API calls¶

Enter your credentials¶

Get tokens¶

Refresh access token¶

Get structures and devices¶

Get device stats¶

Set thermostat to HEAT¶

Set a new temperature¶