The C by GE Sol is that ring shaped smart lamp. GE shut down the Cync cloud it leaned on, so the official app can't reach it anymore, and a lot of these lamps quietly turned into expensive paperweights.
This project talks to the Sol directly over your own WiFi. No cloud, no login, nothing leaving the house. It's an Android app with a glowing dial for brightness and warm-to-cool white, plus the protocol notes so anyone can build their own tool if they'd rather.
I built it to save my own lamp. If you've got one too, hopefully it saves yours.
- On and off
- Brightness
- White temperature, warm through cool
- The small indicator ring (clock dots, the red mic mute light)
- It reconnects on its own, and can stay connected in the background if you turn that on
- Everything happens on your local network
- The ring countdown timer. There's no command for it. That was an Alexa voice feature, and the lamp only lights those segments when it's actually running a timer it set itself.
- Built in Alexa. It went down with GE's cloud and there's no way to bring it back locally.
- First time setup of a factory reset lamp. This assumes your lamp was already paired once with the old app, so it still holds its access keys. Fresh pairing without the cloud is not solved here.
The lamp speaks a WiFi protocol from XLink, an IoT device cloud run by Guangzhou Xlink IoT Technology (brand 云智易 / Yunzhiyi, at xlink.cn). You send it small framed packets for on/off, brightness, and color, over the local network, wrapped in DTLS. The app finds the lamp by scanning for it on the LAN, or by going straight to its IP address if you're on a different access point, then sends those packets. The full breakdown is in docs/PROTOCOL.md.
The app needs one thing this repo can't hand you: the XLink WiFi SDK and two small native libraries. Those belong to GE and XLink, so they are not here. You pull them out of your own copy of the GE app, which you already own, as part of building. docs/BUILDING.md walks through the whole thing.
That's also why there's no ready made APK to download. Shipping one would mean shipping GE's code to everyone, which isn't ours to do. If someone reimplements the XLink and DTLS layer from scratch, a real one tap install becomes possible. Until then it's build it yourself, and honestly that part takes an afternoon.
This is a personal interoperability project for hardware I own. It is not endorsed by or connected to GE, Savant, Cync, or XLink. Their names show up only to describe what the thing is and how it talks.
Other people have done really good local control for the C by GE and Cync WiFi bulbs and plugs, mostly through Home Assistant and a cloud redirect trick. If that's your device, go look at cync-lan and unixpickle/cbyge.
If your gear isn't GE at all, the same XLink SDK turns up in other products. The clearest example is the MiLight (Mi-Light) app, which carries the same io.xlink.wifi.sdk and talks to the shared xlink.cn cloud. Its traffic looks a lot like the Sol's, so these notes carry over if you're mapping a non-GE XLink device.
This project is the odd one out: it's specifically the Sol ring lamp, driven from a phone.
MIT for the code I wrote, see LICENSE. The XLink SDK and the native libraries are third party and are not included or relicensed here.