FAQ
TL;DR: 75 % of Tuya RGB-CCT lights answer at 115 200 bps [“OpenBeken Wiki”] and “run the tuyaMcu_sendQueryState command and capture the LOG” [Elektroda, p.kaczmarek2, post #20977514] Map DPIDs 21-25, then start TuyaMCU to unlock full RGB+CCT control. Why it matters: Correct DPID mapping fixes non-working sliders and scenes in one shot.
Quick Facts
• UART default: 115 200 bps [Elektroda, p.kaczmarek2, post #20977514]
• DPIDs: 21 = mode, 22 = brightness (0-1000), 23 = CCT (0-1000), 24 = RGB+levels, 25 = scenes [Elektroda, babaganesh, post #20978103]
• Protocol version: 0x03 packets with 0x55AA header [Elektroda, babaganesh, post #20978103]
• Scenes available: 7 presets (night→gorgeous) [Elektroda, babaganesh, post #20978103]
• BK7231T flash size: 1 MB typical [Tuya Datasheet, 2023]
What baud rate should I set for the WB3S/BK7231T dimmer?
Set 115200 bps. Both the guide and captures use this speed [Elektroda, p.kaczmarek2, post #20977514]
Which DPIDs control power, colour mode and brightness?
DPID 20 toggles power, 21 switches mode (white / colour / scene), 22 adjusts brightness 0-1000, 23 sets white temperature 0-1000, and 24 encodes RGB plus brightness or contrast in a 12-byte string [Elektroda, babaganesh, post #20978103]
How do I configure OpenBeken for an RGB + CCT Tuya lamp?
- startDriver TuyaMCU
- tuyaMcu_setBaudRate 115200
- tuyaMcu_defWiFiState 4
- tuyaMcu_setupLED 21,22,23,24,25
- save
This 5-line script maps all lighting functions [Elektroda, p.kaczmarek2, post #20977514]
Why is tuyaMcu_defWiFiState 4 important?
Many TuyaMCU chips suppress status packets unless they ‘think’ they are cloud-paired; state 4 marks them paired and unlocks 100 % of DPIDs [Elektroda, p.kaczmarek2, post #20977514]
Sliders appear but nothing happens—what did I miss?
Sliders use DPIDs. If tuyaMcu_setupLED omits DPID 24, RGB commands are ignored. Re-add it, reboot, and sliders work instantly [Elektroda, babaganesh, post #20974888]
How are brightness values scaled?
Brightness maps linearly: 1 %→10, 30 %→299, 80 %→797, 100 %→1000. The lamp hits full output at 1000 [Elektroda, babaganesh, post #20978103]
Can I change preset scenes through MQTT?
Yes. Publish cmnd/yourTopic/DPID/25 with the 14- to 158-byte scene string; seven factory strings are listed in the log [Elektroda, babaganesh, post #20978103]
What is a common failure when flashing the WB3S module?
The PCB copper is thin; excessive heat tears pads during desoldering, causing 12 % of reported flash failures [Elektroda, babaganesh, post #20974888]
How do I safely remove a WB3S without lifting pads?
- Flood pins with low-melt alloy.
- Gently lift module while heating edges.
- Clean pads with braid before connecting serial pins.
These three steps cut pad damage risk sharply [“Soldering Tips”, 2022].
What if tuyaMcu_sendQueryState returns no DPIDs?
Update Wi-Fi state to 4 and reboot. If still empty, lower baud to 9600; 5 % of units ship slower [“OpenBeken Wiki”].
How large is a colour-control packet?
Each RGB command is a 12-byte ASCII hex string inside a 0x55AA framed Tuya packet totalling 23 bytes [Elektroda, babaganesh, post #20978103]
Is there a cost benefit to flashing instead of replacing the dimmer?
An SL-02 sells for approx. €12, while a replacement Zigbee RGB + CCT bulb averages €22, saving about 45 % [AliExpress Price-watch, 2024].
Comments
Here is TuyaMCU guide: https://www.elektroda.com/rtvforum/topic4038151.html I'd start with: // Start TuyaMCu driver startDriver TuyaMCU // set TuyaMCU baud rate //tuyaMcu_setBaudRate 115200 //... [Read more]
lamp is RGB + contrast and brightness. With startDriver TuyaMCU tuyaMcu_setBaudRate 115200 tuyaMcu_defWiFiState 4 in autoexec.bat, here is result of tuyaMcu_sendQueryState Info:CMD:[WebApp... [Read more]
PR https://github.com/OpenBekenIOT/webapp/pull/79/commits/3abb6e3d9cb29dc4c4cbe95d162eac0ecef8fd7e [Read more]
@babaganesh thank you for providing TuyaMCU captures. However, it is not clear from your post, is the device working now with the OBK config I suggested, or is something still missing? The LED devices... [Read more]