Making existing lighting HomeKit compatible with the Shelly 2.5 smart relay
September 01, 2021
A cikk magyar változatáért kattints ide.
The Starting Point 💭
When setting up the lighting in my apartment, I aimed to use Philips Hue systems throughout. However, I overlooked two areas: the lighting in the bathroom mirror cabinet and the LED strip above the kitchen counter. In my defence, the bathroom cabinet was already installed when we bought the apartment, and the kitchen LED was installed by the carpenters along with the cabinetry. In today’s article, I’ll explain how I made these lights controllable via HomeKit relatively cost-effectively.
Possible Solutions 🤔
The obvious solution would be simply replacing the two GU10 bulbs in the bathroom cabinet with Hue bulbs and swapping the 4.5-meter LED strip in the kitchen with a Hue-compatible one. Alternatively, since neither dimming nor colour-changing is essential in these areas, we could consider making the existing lighting “smart” without replacing it.
First Option – Go All In with Philips Hue! 💡💰
Then I looked at the prices: Hue LED strips are sold by the meter (the base is a 2-meter strip with a power supply, extendable by 1-meter segments), and you can connect them, but at the join, there’s a 2-4 cm gap where no diode lights up. The 2-meter starter kit with a power supply costs around 28,000 HUF, with each additional meter costing 9,000 HUF. Since I need 4.5 meters, I’d have to buy 5 meters and cut it at the designated spots (the system is designed to allow cutting at specific points). Plus, I’d need a Hue switch, such as a Hue Smart Button, which adds another 10,000 HUF.
I’d need two GU10 bulbs for the bathroom mirror cabinet. The White Ambiance version costs 17,000 HUF, plus another Hue Smart Button for an additional 10,000 HUF.
As I mentioned, all I need for both areas is basic on/off functionality; I don’t need dimming or color-changing.
So, the kitchen LED setup would cost around 65,000 HUF. The bathroom cabinet would be about 27,000 HUF, which means the cost would be around 110,000 HUF, not including another 10,000-15,000 HUF for electrical work (it’s quite a hassle to solder and install the LED strip in the kitchen).
110,000 HUF is quite a bit for this level of convenience.
Option Two – Shelly 2.5 Smart Relay 🎚️
Another option is to skip swapping out specific bulbs and make the existing lights HomeKit-compatible. After thorough research, I concluded that the Shelly 2.5 relay was the best choice (even though the Shelly 1 could work, the 2.5 is reportedly smaller and fits into the wall more easily).
The Shelly 2.5 is a small smart relay that can be connected behind the existing wall switch and is Wi-Fi-controlled.
Note: Since it supports power monitoring, it also requires a neutral wire!
Each Shelly 2.5 unit cost me 9,500 HUF (I ordered from Alza), and the electrical work took about 3 minutes, so it was a cheap setup (I think the electrician charged me just 1,000 HUF).
But How Does This Work with HomeKit? 🏠
Shelly devices aren’t officially HomeKit-certified, so they don’t integrate directly into the HomeKit ecosystem.
There are two options: either use a HomeBridge plugin or replace the relay’s control software with a HomeKit-compatible version.
I chose the second route because it seemed much more straightforward.
Flashing HomeKit Firmware ✨
First, ensure the relay is wired behind the switch according to your intended use. Since I’m not experienced with electrical work, I had an electrician handle this, and it only took a few minutes.
Once connected, download the Shelly app on iOS, register, and add the installed relay to the software. This step is essential because this is how the relay receives the Wi-Fi network details. The primary goal here is to get the relay onto your network.
Once this is done, let’s update to the latest factory firmware version (5 minutes). Then, test whether the device works and is connected properly (turn it on and off from the app)!
If everything is in order, the next task is to assign the Shelly relay a fixed IP address.
This can be done from the control panel of our own router.
After that, there’s only one simple step left:
Visit the GitHub page of the team that developed the HomeKit firmware, select the update link that matches the version of the Shelly relay you purchased and installed, open a browser, paste the link, and press Enter.
For the Shelly 2.5, use this link to load the HomeKit firmware:
http://A.B.C.D/ota?url=http://rojer.me/files/shelly/shelly-homekit-Shelly25.zipWhere http://A.B.C.D is the fixed IP address assigned to your Shelly.
After a few minutes, the HomeKit control software interface will load on this IP address. Here, you can set the switch type (the 2.5 version can even be used for controlling blinds) and disable the second relay if you’re only using one (the 2.5 supports two circuits, but I only needed one, so I disabled the other in the software). You’ll also get the QR code to add the switch to the Home app.
You can delete the original Shelly app from this point, as it can no longer control the device with the custom HomeKit firmware.
A fantastic feature is that the existing physical light switch remains usable (unlike with Hue). Turning the lights on manually will also show as “on” in HomeKit, and vice versa.
Verdict 📄
If you don’t need to adjust brightness, colour temperature, or colours, the Shelly 2.5 smart relay is clearly a great choice. It meets basic needs at a fraction of the cost and operates reliably.
However, check how much space is available behind the switch, as there might not be enough room for the device. I chose the 2.5 model specifically because it’s somewhat smaller than the 1.
Always have a professional handle any electrical work!
