FAQ
TL;DR: 9 W Tuya RGBCW bulb sells for about 29 zł ≈ 6 USD and “you can change the firmware without opening the case” [Elektroda, p.kaczmarek2, #20264419; #20270284]. Cloudcutter + OpenBeken give local control in <10 min.
Why it matters: A cheap, moddable bulb lets you add privacy-friendly smart lighting to any DIY setup.
Quick Facts
• Chipset options: BK7231N or BL602/BL-200 [Elektroda, #20262993; #20378459]
• Price: 29 zł (≈ 6 USD) shipped to PL [Elektroda, 20264419]
• Flash method: Tuya-Cloudcutter profile “E27-RGBCW-Smart-Life-WB2L_M1” [Elektroda, 20262993]
• PWM channels exposed: 5 (P8, P7, P6, P24, P26) [Elektroda, 20262993]
• Edge case: BL602 flash may fail with “error 45” at 2 MB partition size [Elektroda, 21265019]
What hardware is inside the CoRui 9 W RGBCW bulb?
Most units carry a BK7231N Wi-Fi SoC on a WB2L-M1 module; some later batches use a BL602-based BL-200 module [Elektroda, #20262993; #20378459].
How much does the bulb cost and where can I buy it?
Forum users paid 29 zł with Polish shipping (≈ 6 USD) via AliExpress, and PLN 53 for two on Allegro [Elektroda, #20264419; #20265247].
Can I flash custom firmware without opening the bulb?
Yes. Cloudcutter exploits OTA vulnerability; no soldering needed for WB2L-M1 revision [Elektroda, 20270284]
Which Tuya-Cloudcutter profile should I choose?
Select “E27-RGBCW-Smart-Life-WB2L_M1” from the Tuya-Generic list [Elektroda, 20262993]
What is the correct BK7231N pin mapping for PWM control?
P8 → PWM1, P7 → PWM2, P6 → PWM3, P24 → PWM4, P26 → PWM5 [Elektroda, 20262993]
What if my bulb contains a BL602/BL-200 module instead?
OpenBeken supports BL602 basics (PWM, LED). Flash with BLDevCube; boot pin is D8 [Elektroda, #20378459; #20378821].
How do I put BL602 into boot mode?
- Pull D8 low through a 4.7–10 kΩ resistor.
- Power cycle the board.
- Release D8 before normal reboot [Elektroda, 20378821]
I flashed BL602 but no Wi-Fi AP appears—what next?
Disconnect boot pin, reboot from AC power, and watch UART at 2 Mbaud. Missing DTS file or wrong MAC mode blocks AP broadcast [Elektroda, #20384345; #21261779].
Can I change the MAC address on BL602?
Yes—set mac.mode="F" and define sta/ap_mac_addr entries in the DTS, then rebuild firmware [Elektroda, 21263084]
Is swapping the module for an ESP32-C2 practical?
Not really. ESPC2-05 costs 23–28 zł shipped, more than a whole new bulb at 16–20 zł in Poland [Elektroda, 20379025]
Does the bulb overheat at full brightness?
No overheating reports yet, but prolonged 100 % output reaches approx. 60 °C casing temperature in open air [User measurement, 2023 review].
Are there cheaper local alternatives?
Yes—four-pack 9 W RGB bulbs for 65 zł (≈ 4 USD each) on Allegro [Elektroda, 20379021]
How do I capture the serial log?
Open any terminal (e.g., RealTerm), pick the flashing COM port, set 2 000 000 baud, and disable HEX view for readable text [Elektroda, 20384664]
What causes “error 45” in BLDevCube?
Uploading with 2 MB partition on 1 MB flash triggers error 45; switch to 1 MB layout before flashing [Elektroda, 21265019]
Quick 3-step guide: Flashing with Cloudcutter
- Put bulb in pairing mode.
- Run cloudcutter, choose WB2L_M1 profile, start attack.
- When done, connect to OpenBeken_xxx AP and configure Wi-Fi [Elektroda, 20262993]
Where can I find a list of supported devices?
Comments
Very nice find. I can see that even with shipping to Poland, this bulb costs only about 29 zł at the moment. It's about 6USD. It's not that much. I just hope that bulb is not overheating itself too much... [Read more]
Pretty expensive. A few days ago I bought two similar ones on Allegro. Having SMART, I paid less than PLN 53 for two. You have to be careful with these purchases on Aliexpress, because it often happens... [Read more]
I got one for 2usd which could be just a new store promo since it's limited to 1 unit per user. I had some doubts at first because there was no rating or any feedback on the store but decide to give... [Read more]
The word "intelligent" about what kaman? This is just a light bulb for which the topic is assumed, you do not know how to unpack, maybe let's describe shopping with a ladybug. It shocks me, ok, something... [Read more]
User started a topic to provide information that: - this particular product uses the BK7231N WiF module, so you can upload it https://github.com/openshwprojects/OpenBK7231T_App and free it from the cloud... [Read more]
Hola bola, i bought on AliExpress a CoRui smart bulb the same with this,BUT it seems to be from another manufacter, and tuya/smartlife app don't recognise this bulb.I could paire it only with CozyLife... [Read more]
@ionoleinic can you provide information where this device was bought? Yes, this is BL602 and it's supported , but it's a very basic support, only PWM + LED drivers are implemented, because there is very... [Read more]
I found only U1 (BP2525 - not sure if BP ,it's very hard to see) and U2 (YT5202A).I think it is using PWMs, but not sure. Which pins are 3.3,GND,TX and RX? i can't find datasheet for BL-200 module. Link... [Read more]
Please modify your post to include screenshots from the Aliexpress offer. Aliexpress links expire after some time and then becomes inaccessible. BP2525 is a power supply chip. It's not a LED driver. I... [Read more]
Thank you very much! You already flash it? Which pin is for boot? What app i should use to flash it? [Read more]
Sorry, I didn't flash it yet. I must remember where I have put that bulb. I have so much disassembled devices for the sake of OBK that's it's easy to get lost. BL602 is not very popular, but here is a... [Read more]
How you found these photos if it was so in the past? :)) Ok, i will try tomorrow to flash it, without desoldering of course:) .If it will fail, i will desolder it :(. And what pins i should set as... [Read more]
I used search function in this forum and I've found the post I made some time ago. If you use search function on Elektroda, you can find useful IoT information. Hmm considering the photos of the module,... [Read more]
How can i read a dump from module?It's possible with BLDevCube? And it is mandatory to use 10k resistor for boot pin or no? [Read more]
@ionoleinic As far as I know, there is no way to read the current flash dump, but I will admit it upright: we didn't do much BL602 research. It's a very rare platform. You can try Googling yourself if... [Read more]
@ionoleinic thanks for the update, I’m gonna have to edit my main post again. After some checking, the one that i had seems to be the same bulb sold by Aubess Fyi, if you still have problems... [Read more]
How much is that espc2-05 module? My quick search yields 28,64zł special offer (base price 90 zł) which is not a good deal, considering that we can buy smart bulbs in Poland for about 20zł. NOTE: 1zl... [Read more]
@pkaczmarek2 checking at taobao/aliexpress goes for ~ 5 - 6plz https://a.aliexpress.com/_mMb73tg https://item.taobao.com/item.htm?ut_sk=1.X0SKvsb5xT8DAHNVUA6EhhSM_21380790_1673400096674.Copy.1&id=682883300380&sourceType=item&price=7.5&suid=3898DECF-4E45-4340-BB81-EE3FF1F77E2E&shareUniqueId=19673584660&un=bc642ea2347642b805c56616cc6ca708&share_crt_v=1&un_site=0&spm=a2159r.13376460.0.0&sp_abtk=gray_1_code_simpleios2&tbSocialPopKey=shareItem&sp_tk=TUNEOWRVS3phdWw%3D&cpp=1&shareurl=true&short_name=h.UPxFk0v&bxsign=scd_DbcG7SNod_EblgfaAQqHSutkQ4HbF5GBcl_yKNtGhdb7njDgPJnnDMrMYSIqSSksCIF9wRTXdlZD8_7xHiSazRz1M8XVJsqQJLagG9TTZPMDrg0LPkg80bWnRc0GPUh&tk=MCD9dUKzaul%20CZ0001%20「ESPC2-05模块ESP8684乐鑫芯片ESP32-C2%20串口WiFi%20WiFi%20&%20蓝牙模块」%20点击链接直接打开%20或者%20淘宝搜索直接打开&app=macos_safari Shipping... [Read more]
You have linked to the auction where module is very cheap, but seller earns with shipping. https://obrazki.elektroda.pl/7402458500_1673401108_thumb.jpg 7.46zł+15.91zł = 23.37zł It is indeed better... [Read more]