I found a way to get the RFM69HCW "packet mode" to produce packets that were compatible with the Somfy RTS protocol This is the result of that experiment getting way out of hand:
Pico Somfy in a DIY hardware project for controlling Somfy Blinds in Home Assistant (or with MQTT/HTTP). It also listens to signals from real Somfy remotes, so it can know if the blinds have been moved outside of its control. This is useful because the Somfy protocol is one-way.
It can be put together using a cheap Raspberry PI Pico W and an RFM69HCW module. You can put this together on a breadboard, but it's very very cheap to manufacture a prototype PCB now too.
The (my first) EasyEDA PCB layout is provided in the pcb folder. You can get 5 boards manufactured by JLC PCB about $5, delivered!
The Pi Pico W runs a small React web interface that lets you configure blinds and any additional remotes. Blinds are exposed to Home Assistant through MQTT discovery as Covers. The position of the blinds are estimated based on open/close timings.
Additional Remotes can be created, and bound to several blinds, to allow group control. These are exposed to home assistant as buttons, not covers. Operating a remote will update the position of the associated covers.
With JLC PCB, total cost to manufacture the PCB and buy the parts is about £20.
Required:
- Pi Pico W - £4.80
- RFM69HCW 433Mhz - £4.99
- Ceramic Capacitor - £0.06 (or you can buy the Adafruit breadboard module which includes the capacitor on-board)
Optional:
- Status LEDs
- Tactile Switches x 2 - I bought ones with the wrong pins cross-connected. Oh well.
- There is a position for an edge-mount antenna connector. I couldn't find a cheap option to use, but a better antenna really isn't needed anyway. Any short bit of wire would probably do.
- Open Visual Studio Code in the
firmwarefolder. - From the terminal run
./generate_fsdata.sh. This builds the web interface project, which is then squeezed onto the Pi Pico. - Use the CMake plugin to build the project using the unspecified architecture. This will automatically use the Pico SDK.
Hold down BootSel while plugging in the Pi Pico W.
Copy the somfy_remote.uf2 file from the build/ directory to the Pico drive that appears.
If you need to update the firmware, you can re-enter firmware mode via the web interface too.
When initially started for the first time, the pico starts in WiFi setup mode (green status LED shows). It will appear as a WiFi access point called "pico_somfy". Connect to that access point with the password "password".
Go to http://192.168.4.1 to access the setup interface. Here you can select your Wifi network from the drop-down list and enter your WiFi credentials so Pico Somfy can connect to your network. Note: Pi Pico only supports Wifi 2.4G.
Click Save & Reboot.
Pico Somfy should start up and connect to the Wifi network. You should see a pulsing red light which indicates WiFi is connected and has an IP address assigned. If the light does not light, the WiFi connection could not be established. You can re-enter WiFi setup mode by pressing Reset for a short press, and then holding the WiFi button for about 10 seconds during startup until the green LED lights steadily.
Next, Figure out what IP address your Pico Somfy has been assigned. You can get this from your router. The device should show up as pico_somfy in your router client list. Then go to the web interface at http://<your-pico-ip-here> to configure your Pico Somfy.
You can then go to the Network Setup page to add your MQTT configuration settings. This is required for Home Assistant integration. Once MQTT is connected, you will see a pulsing green status light.
Blinds can be added from the Control Blinds page. I reccomend you add a blind for each blind you want to control first and then add additional remotes to group them together as required.
If you want to import a real remote, there is a button for that. This allows you to bind the real remote to your blind instances, so that the system knows which blinds will move when the remote is activated. While you can issue commands as if they came from the real remote, this will get the rolling codes out-of-sequence, so isn't a good idea. Better to create a new blind remote, and use the Somfy copy/paste.
You can bind remotes to blinds in the edit page:
;
The Blind control page and interface is pretty rough around the edges, and not designed to be used for any more than setting up the blinds and testing the functions. Use Home Assistant or the MQTT/HTTP API for control and automation.
To add a remote to a brand new blind (or after a factory reset), long press the up-down buttons. This then enters the blind setup procedure where you can use various button combinations to set the direction of the blinds and the blind limits.
To configure a blind that already has a remote associated with it, long-press the program button on the existing remote. Then short-press the program button on the new blind's remote (see the ... button on the blind controls):
Some Somfy documentation says you need a long-press. This may be true of some blinds, but not mine.
Adding additional remotes has a built-in bind/unbind feature in the web interface. Choose which of your existing blinds you want the remote to control.
I designed a simple 6cm x 6cm x 1.5cm square case to hold the circuit board and expose the buttons and status LEDs.
The Fusion 360 and STL files ca be found in the case/ directory. Print the lid and buttons face-down.
No Supports are needed. I changed filament half way through printing the lid to make the recessed logo
stand out.
- I've found some sources detailing other Somfy remote code standards which should be fairly easy to add. I don't have these blinds so I can't test this
- At the moment, we don't have any good way of activating tilt on a tilt & lift blind. I think there are various chords of button presses needed to activate these, depending on the blind & region
- The web UI do with some serious polish
This project relied heavily on the Somfy RTS protocol decoding which was done by PushStack.
The original idea came from the Pi-Somfy project from Nickduino. This fantastic project is only let down by the unreliable radio module whose radio frequency would seemingly change with the weather. I started trying out the RFM69 module instead, but ended up trying to control it from a £6 Pico W for what was supposed to be "fun".
MIT Open Source license.