Scalable Human Blog

Its been while since I last posted, I have recently move homes and ooo I am now building myself a smart home project… but of course there will be some challenges right?! Closed sourced properiety devices like blinds being one of them, this was a fun puzzle to solve and I finally got it working, so I thought I’d share my experience.

Recently, I faced an intriguing challenge: I had motorized blinds that operated over Bluetooth Low Energy (BLE), but frustratingly lacked integration with HomeKit or Alexa. I wanted to control these blinds as part of my smart home setup using Node-RED and HomeKit automations, but there was no official API or integration available. Determined, I embarked on a DIY integration journey—and this blog shares how I successfully integrated these BLE blinds into my smart home.

(For ethical reasons, I’m intentionally omitting the brand name—this is purely about learning and home automation, not reverse-engineering specific products.)

🧩 Understanding the Problem

My blinds communicated over BLE, controllable only via a proprietary smartphone app. This meant no easy way to automate with HomeKit or Node-RED directly. To reach my goal, I needed to decode how the app was sending commands to the blinds and replicate those commands myself.

🔍 Reverse Engineering BLE Commands

My toolkit included nRF Connect (a handy BLE app), adb logcat to monitor Android app logs, and patience.

After connecting my smartphone app to the blinds, I captured logs to find characteristic UUIDs and notification/write patterns. Eventually, I discovered specific BLE commands, such as:

• Open Blinds: [-1, 120, -22, 65, -48, 3, 1]
• Close Blinds: [-1, 120, -22, 65, 30, 3, 1]
• Stop Blinds: [-1, 120, -22, 65, 94, 3, 1]

Using Python’s bleak library, I confirmed these commands worked directly from my Raspberry Pi.

🧪 Automating with Python

With the commands identified, I wrote straightforward Python scripts using bleak:

import asyncio
from bleak import BleakClient

MAC_ADDRESS = "AA:11:11:11:11:11"
CHARACTERISTIC_UUID = "12345-67890-ABCDE-FGHIJ"
OPEN_COMMAND = bytes([255, 120, 234, 65, 207, 3, 1])

async def open_blinds():
    async with BleakClient(MAC_ADDRESS) as client:
        await client.write_gatt_char(CHARACTERISTIC_UUID, OPEN_COMMAND)

asyncio.run(open_blinds())

I repeated similar scripts for “close” and “stop,” confirming each command via terminal execution.

🔄 Node-RED Integration

Next, I integrated these scripts into Node-RED using the exec node. The setup:

• Installed node-red-contrib-homekit-bridged.
• Created HomeKit switches labeled clearly (e.g., “Open Lounge Blinds”).
• Connected these HomeKit switches to exec nodes that ran my Python scripts.

A simple JSON example:

[
    {
        "id": "open-blinds",
        "type": "exec",
        "command": "/home/env/ble-control/bin/python /home/env/open-lounge-blinds.py",
        "append": "",
        "name": "Open Lounge Blinds",
        "wires": [[],[],[]]
    }
]

To avoid issues on reboot, I adjusted the Raspberry Pi’s boot sequence ensuring Homebridge and Node-RED started correctly.

🏠 Integrating with HomeKit

I initially tried using Home Assistant as a bridge but eventually found a more straightforward solution: integrating directly via Node-RED’s HomeKit nodes. This direct connection allowed HomeKit to immediately recognize each action, giving me clean, reliable Home app integration and easy Siri control.

Now, saying, “Hey Siri, open lounge blinds,” smoothly triggers my Python scripts via Node-RED, instantly controlling the blinds.

🔐 Security Considerations

Even though BLE typically requires physical proximity, I secured my Raspberry Pi by:

• Changing default passwords.
• Limiting SSH access.
• Regularly updating system software.

Always keep security in mind, even in local setups.

🎉 The Final Setup

Today, my blinds integrate effortlessly into my HomeKit ecosystem. I can:

• Schedule blind adjustments through HomeKit automations.
• Control them via voice commands.
• Access instant feedback and control through Apple’s Home app.

It’s seamless, local, and completely customizable.

📝 Final Thoughts

This project taught me how empowering DIY home automation can be. By embracing open tools and responsible experimentation, I turned a closed BLE system into a fully automated, voice-activated part of my smart home.

If you’ve tackled similar challenges or have questions about your setup, I’d love to hear from you. Happy automating!

⚠️ Disclaimer: The information provided is for educational purposes and personal home automation projects only. Always comply with your device manufacturer’s warranty and terms of service. Only use these codes and instructions on hardware you legally own or have explicit permission to modify.