Building a Smart Home Roller Shutter Controller with ESP32 and Somfy RTS

Official Somfy smart home bridges cost €150-200. This DIY solution costs about €15 and works just as well.

This guide covers the complete build: hardware, wiring, firmware, Home Assistant integration.

Hardware Required

Total cost: ~€15

ESP32 WROOM-32 DevKit (~€5)
CC1101 433MHz RF Module (~€3)
433MHz SMA Antenna (~€2)
Dupont Jumper Wires (~€1)

The ESP32 handles WiFi and logic. The CC1101 transmits on 433MHz, the frequency Somfy uses.

Wiring

CC1101 Pin → ESP32 GPIO
────────────────────────
VCC (Pin 1)  → 3V3
GND (Pin 2)  → GND
GDO0 (Pin 3) → GPIO 13
CSN (Pin 4)  → GPIO 5
SCK (Pin 5)  → GPIO 18
MOSI (Pin 6) → GPIO 23
MISO (Pin 7) → GPIO 19
GDO2 (Pin 8) → Not connected

Important: Use GPIO 13 for GDO0

GPIO 4 has boot behavior issues on the ESP32. I initially wired GDO0 to GPIO 4. Reception worked but transmission failed. Moving to GPIO 13 fixed it.

Antenna is Required

Without the antenna: ~1 meter range. With the antenna: 15+ meters through walls. Don't skip it.

Firmware Installation

Arduino IDE Setup

Add the ESP32 board URL in File → Preferences → Additional Board Manager URLs:

https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json

Critical: Use ESP32 Core 2.0.17

ESP32 Core 3.x has breaking changes. Install version 2.0.17 specifically.

Tools → Board → Boards Manager → ESP32 → Select 2.0.17

Get the Firmware

git clone https://github.com/rstrouse/ESPSomfy-RTS.git

Required Libraries

Install via Arduino Library Manager:

ArduinoJson (v7.0.4)
WebServer_ESP32_W5500 (v1.5.3)

Install manually from GitHub (download ZIP, then Sketch → Include Library → Add .ZIP):

AsyncTCP
ESPAsyncWebServer

Flash Settings

Board: ESP32 Dev Module
Upload Speed: 921600
Flash Size: 4MB
Partition Scheme: Default 4MB

First Boot

Wait 30 seconds after flashing
Connect to WiFi network "ESPSomfy-RTS"
Open http://192.168.4.1

The web interface provides a dashboard, shutter controls, and settings.

Pairing With Shutters

Put Motor in Programming Mode

With an existing remote:

Press and hold the PROG button (small hole on back) for 3 seconds
Shutter will jog (quick up-down movement)
You have 2 minutes to complete pairing

Pair the ESP32

In ESPSomfy web interface: Shades → Add Shade
Enter a name
Click PROG button in interface
Shutter jogs again to confirm pairing

Test with UP, STOP, DOWN controls.

Home Assistant Integration

MQTT Setup

Install Mosquitto broker add-on in Home Assistant:

Settings → Add-ons → Add-on Store → Mosquitto broker → Install

Configure ESPSomfy MQTT settings:

Settings → Network → MQTT:
  Enable MQTT: ✓
  Broker IP: [Your Home Assistant IP]
  Port: 1883
  Discovery Topic: homeassistant

Firewall Note

If MQTT won't connect (error -2), check that port 1883 is open for local traffic.

Auto-Discovery

Once MQTT connects, shutters appear automatically in Home Assistant. No YAML configuration needed.

Useful Automations

Morning: Open shutters at sunrise + 20 minutes

Evening: Close all shutters at sunset - 15 minutes

Heat protection: Close to 70% when outdoor temperature exceeds 28°C

Vacation mode: Random opening/closing throughout the day

Results

What works:

5 shutters responding reliably
15+ meter range through walls
Response time under 1 second
Stable operation over weeks

Common issues to avoid:

Use GPIO 13 for GDO0, not GPIO 4
Use ESP32 Core 2.0.17, not 3.x
Install the antenna
Open port 1883 for MQTT

In the end

For ~€15 and a few hours of work: complete control of Somfy shutters, voice control via Google Home, smart automations based on sun and temperature.

The ESPSomfy-RTS firmware is stable and actively maintained. If you have Somfy RTS shutters and basic soldering skills, this project is worth the effort.