pycync_lan (cync_lan)

Important

DNS redirection REQUIRED

Async MQTT LAN controller for Cync/C by GE devices. Local only control of most Cync devices via Home Assistant (MQTT JSON payloads).

This is a work in progress, and may not work for all devices. See known devices for more information.

Forked from cync-lan and cync2mqtt - All credit to iburistu and juanboro

Prerequisites

• A minimum of 1, non battery powered, Wi-Fi Cync device to act as the TCP <-> BT bridge. I recommend a plug, wired switch or an always powered wifi bulb - The wifi device' can control BT only bulbs
• Cync account with devices added and configured
• MQTT broker (I recommend EMQX)
• Create self-signed SSL certs using CN=*.xlink.cn for the server. You can use the create_certs.sh script.
• Export devices from the Cync cloud to a YAML file; first export requires cync email, password and an OTP emailed to you.
• DNS override/redirection for cm.gelighting.com or cm-ge.xlink.cn to a local host that will run cync-lan.
• Optional: Firewall rules to allow cync devices to talk to cync-lan

The only way local control will work is by re-routing DNS traffic from the Cync cloud server to your local network, you'll need some way to override DNS - a local DNS server; OPNSense/pfSense running unbound, Pi-Hole, etc. See the DNS docs for more information.

Installation

Please see Install docs for more information.

Re-routing / Overriding DNS

Warning

After freshly redirecting DNS: Devices that are currently talking to the Cync cloud will need to be power cycled before they make a DNS request and connect to the local cync-lan server.

There are detailed instructions for OPNSense and Pi-hole. See DNS docs for more information.

As long as your DNS is correctly re-routed, you should be able to start the server and see devices connecting to it. If you do not see any Cync devices connecting after power cycling them, you may need to check your DNS re-routing and firewall rules (if applicable).

Testing DNS override

Warning

If you are using selective DNS override via views in unbound, and you did not set up an override for the IP of the machine running dig / nslookup, the command will return the Cync cloud IP, this is normal.

you can use dig or nslookup to test if the DNS override is working correctly.

# Older firmware
dig cm-ge.xlink.cn

# Newer firmware
dig cm.gelighting.com

# Example output with a local A record returned
; <<>> DiG 9.18.24 <<>> cm.gelighting.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 56237
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;cm.gelighting.com.             IN      A

;; ANSWER SECTION:
cm.gelighting.com.      3600    IN      A       10.0.1.9 <---- Overridden to a local machine running cync-lan

;; Query time: 0 msec
;; SERVER: 10.0.1.1#53(10.0.1.1) (UDP)
;; WHEN: Fri Mar 29 08:26:51 MDT 2024
;; MSG SIZE  rcvd: 62

Config file

Important

At the moment, the config file will override any environment variables set.

It is required to query the Cync cloud API to export all your homes and the devices in each home. This requires your email, password and the code that will be emailed to you during export.

If you add or remove devices, you should re-export the config file and restart the server.

See the example config file

Export config from Cync cloud API

There is an export sub command that will query the Cync cloud API and export all homes and each homes devices to a YAML file.

Manually adding devices

To manually add devices to the config file, look at the example and follow the template. From what I have seen the device ID starts at 1 and increments by 1 for each device added to the "home" (it follows the order you added the bulbs).

It is unknown how removing a device from the cloud and adding a device may affect the ID number, YMMV. Be careful when manually adding devices.

Note

By manually adding, I mean you added a device via the app and did not re-export a new config.

CLI arguments

You can always supply --help to the cync-lan.py script to get a breakdown. Please see the sub-command docs for more information.

Env Vars

Variable	Description	Default
CYNC_MQTT_URL	URL of MQTT broker	mqtt://homeassistant.local:1883/
CYNC_DEBUG	Enable debug logging	0
CYNC_RAW_DEBUG	Enable raw binary message debug logging	0
CYNC_CERT	Path to cert file	certs/server.pem
CYNC_KEY	Path to key file	certs/server.key
CYNC_PORT	Port to listen on	23779
CYNC_HOST	Host to listen on	0.0.0.0
CYNC_TOPIC	MQTT topic	cync_lan
CYNC_HASS_TOPIC	Home Assistant topic	homeassistant
CYNC_MESH_CHECK	Interval to check for online/offline devices	30

Controlling devices

Devices are controlled by JSON MQTT messages. This was designed to be used with Home Assistant, but you can use any MQTT client to send messages to the MQTT broker.

Please see Home Assistant MQTT documentation for more information on JSON payloads. This repo will try to stay up to date with the latest Home Assistant MQTT JSON schema.

Home Assistant

This script uses the MQTT discovery mechanism in Home Assistant to automatically add devices. You can control the Home Assistant MQTT topic via the environment variable CYNC_HASS_TOPIC.

Debugging / socat

If your devices are not responding to commands, it's likely that the TCP communication on the device is different. You can either open an issue and I can walk you through getting good debug logs, or you can use socat to inspect (MITM) the traffic of the device communicating with the cloud server in real-time yourself by running:

# Older firmware devices
socat -d -d -lf /dev/stdout -x -v 2> dump.txt ssl-l:23779,reuseaddr,fork,cert=certs/server.pem,verify=0 openssl:34.73.130.191:23779,verify=0
# Newer firmware devices (Notice the last IP change)
sudo socat -d -d -lf /dev/stdout -x -v 2> dump.txt ssl-l:23779,reuseaddr,fork,cert=certs/server.pem,verify=0 openssl:35.196.85.236:23779,verify=0

In dump.txt you will see the back-and-forth communication between the device and the cloud server. > is device to server, < is server to device.

Firewall

Once the devices are local, they must be able to initiate a connection to the cync-lan server. If you block them from the internet, don't forget to allow them to connect to the cync-lan server.

OPNsense Example

Please see the example in the troubleshooting docs.

Power cycle devices after DNS re-route

Devices make a DNS query on first startup (or after a network loss, like AP reboot) - you need to power cycle all devices that are currently connected to the Cync cloud servers before they request a new DNS record and will connect to the local cync-lan server.

Troubleshooting

If you are having issues, please see the Troubleshooting docs for more information.

Buy devices to be supported

If you really want a device added, purchase it from this Amazon wish list and it will be sent to me. I will add support ASAP.