I. Background
When zigbee sub-devices go offline abnormally or the control fails, it may be caused by the poor signal quality of the zigbee network. You can further investigate the causes and improve the signal quality according to the following chapters.
2. Network information acquisition
The zigbee network information that needs to be obtained is: channel, gateway transmitting power, and sub-device network signal.
(1) How to obtain the zigbee channel of the gateway
Please refer to link
(2) How to obtain the gateway transmission power
- Note: The transmission power will be adjusted according to the area code/country code of the gateway. The normal pwr for China is 19, and the default PWR for other countries is 13. (If the transmission power is abnormal, it is recommended to restart the gateway or upgrade the gateway under safe conditions, or contact Tuya's after-sales technical support.)
Method 1: After the SDK is started, a ZigbeeNetInfo.txt file will be generated in the directory specified by the .storage_path variable, which also stores the gateway transmit power.
Example：
Code: Select all
$ cat zigbeeNetInfo.txt
Node ID:0
Pan ID:0x0044
Radio Channel:20 # Zigbee channel
Radio Power:19 # Zigbee pwr
Extended Pan Id: 158F733C2F2325A6
EUI64: F1F2D3FEFFD76B08
Global Key: A2 42 0D D6 50 DD 3B C3 1E CD BD 82 8A 19 E4 92
Global FC:0xFFFFFFFF
Network Key: A5 DA 43 DE 24 A3 7D 54 7A 6B 32 F1 EF 01 E3 A6
Network FC:0x00005001
Network Sequence Number:0x00Method 2: Search for the keyword 'pwr' in the log
Example：
Code: Select all
[12-16 01:10:18:680 TUYA D][tuya_z3.c:34470] country code:, region:AY.
[01-02 15:08:30:860 TUYA D][z3_slabs.c:790] Success: emberSetRadioPower, power = 19.
[01-02 15:08:30:860 TUYA D][z3_slabs.c:799] page [0] chan [20] pwr [19].(3) How to obtain the sub-device signal (Lqi or Rssi)
Method: Please refer to the link, generally speaking, if the APP interface shows that the signal strength is "average" or "poor", or the LQI value is less than 150, it can be considered that the signal strength of the device is poor, and it is recommended to improve it through the subsequent chapter steps, otherwise, if the LQI is greater than 200, there is still offline or control abnormality, then it is recommended to check from other angles.
- Complementary Concepts:
- LQI: link quality index (value range: 0 to 255), the higher the value, the better the link connection quality.
- RSSI: Received signal strength, in dBm, generally between -30 and -90, the higher the value, the better the signal.
3. Common analysis and troubleshooting steps
You can perform the investigation and analysis in the following steps, and each point can be re-obtained to compare whether the signal has been improved:
(1) Physical barriers: such as walls, homes, etc., especially metal objects, are easy to attenuate or reflect wireless signals. Do not place the equipment in a metal container, and the antenna should be oriented as perpendicular as possible and with its back to the wall, so as to minimize the obstruction between the equipment;
(2) Device distance: The farther the distance between communication devices, the weaker the signal strength. The analysis can be performed by comparing the LQI of other devices at the same distance, or by adjusting the position of the device;
(3) Hardware quality: mainly consider the antenna, you can listen to the sound by shaking, or unpacking, judge whether the equipment antenna is connected, if it is a user-defined device/gateway, you need to pay attention to the antenna design, it is recommended to choose the recommended model of Tuya, if it is a snap antenna, it is recommended to fix it with dispensing when manufacturing, so as to fall off, resulting in poor contact with the antenna;
(4) Electromagnetic interference: For example, wifi devices, Bluetooth devices, etc., may share the 2.4 GHz frequency band with Zigbee devices, resulting in co-channel interference. In general, the wifi router and the gateway are placed as far away as possible, and then you can use the app that supports channel scanning, such as "Wifi Magic Box", etc., to scan the wifi channel and strength in the current environment, and combined with the zigbee network channel obtained in the second chapter, refer to the following chart to determine whether there is channel overlap between the two, such as zigbee's 20 channel and wifi's 7, 8, 9, There is a conflict in 10 channels. Since the common channels of WiFi are 1, 6, and 11, the preferred channels for Zigbee are 11, 15, 20, and 25. At present, the Zigbee channel of the gateway is automatically selected when creating a network, whether each gateway has the function of manually selecting the channel, please refer to the corresponding manual, and the gateway can only modify the channel when creating the network, once a device joins, it cannot change the channel. In addition, the WiFi channel can be adjusted through the router's configuration interface, and generally can also be adjusted to automatic or manual setting mode, please refer to the actual device usage documentation. In summary, if there is signal interference, the impact can be reduced by shutting down, adjusting the channel of the interfering device, or reducing the signal strength of the interference;
(5) Network congestion: If there are too many devices in the same Zigbee network, it may cause network congestion and reduce signal strength. If the signal quality deteriorates as more and more devices enter the network, you may need to pay attention to this point, and you can reduce the number of devices appropriately to see if there is improvement. If the conditions for packet capture are met, it is best to save the network packets during the abnormal period, so that individual developers can analyze or feedback to Tuya technical support.
====== above, if you still can't improve the problem of weak signal strength, you can contact technical support, welcome to add more troubleshooting methods, thanks for reading ======