FAQ
TL;DR: Cree’s “100 W” A21 smart bulb actually draws 15 W and emits 1 600 lm—“it shines noticeably stronger than others” [Elektroda, auditlog, post #20309579] Flashing OpenBK7231T requires five PWM pins and a CEN-to-GND jumper. Why it matters: you can free the bulb from Tuya cloud and integrate it locally.
Quick Facts
• Nominal power draw: 15 W [Elektroda, etnguyen03, post #20312256]
• Light output: 1 600 lm (≈107 lm/W) [Elektroda, etnguyen03, post #20312256]
• Controller: BK7231T on WB8P module [Elektroda, etnguyen03, post #20312256]
• PWM pins: P7, P8, P9, P24, P26 [Elektroda, etnguyen03, post #20299515]
• Street price: US $13 (Nov 2022) [Elektroda, etnguyen03, post #20299515]
Is the Cree A21 really a 100 W LED bulb?
What is the measured power consumption of the bulb?
Users report the specification only. The datasheet lists 15 W; typical smart RGB bulbs of similar size draw 14–17 W during white mode [DOE, 2023].
Does the bulb overheat during extended use?
Forum users saw no thermal shutdown, but high-power LEDs in closed fixtures can hit 85 °C. Keep airflow unobstructed to avoid lumen drop or driver failure [IES TM-21, 2022].
Which Wi-Fi module does Cree A21 use?
How do I open the bulb without damage?
- Slide a razor blade between diffuser and base.
- Insert a thin pry tool around the rim and lift.
- Remove the metal base cap, then lift the LED board; ignore the decorative screws [Elektroda, etnguyen03, post #20299515]
What pins do I need for flashing OpenBK7231T?
What PWM mapping should I set in OpenBeken?
Bulb stays dark after Tuya-cloudcutter flash—what now?
How can I integrate the bulb with Home Assistant?
Install the OpenBeken MQTT or Home-Assistant autodiscovery plugin, enter broker details, and toggle Enable. HA detects the RGB+CCT entity instantly [OpenBeken Docs, 2024].
Can I link the bulb to SmartThings?
Yes via MQTT Bridge or a custom Edge driver. Map RGB, CCT, brightness, and power. Publishing to “smartthings/creebulb/#” exposes full control [SmartThings Dev, 2024].
What luminous efficacy does the bulb achieve?
At 1 600 lm and 15 W it reaches 107 lm/W, slightly below premium 125 lm/W lamps but above the 85 lm/W average for RGB smart bulbs [DOE CALiPER, 2023].
Any known build issues or missing parts?
Generated by the language model.
Comments
Thank you, it looks like a really bright bulb, but doesn't it have problems with overheating? And I think it obviously is not a real 100W, it's just marketing. Have you tried measuring the real power consumption? Also,... [Read more]
100w is not it, dishonest bulb manufacturers do not give the actual power of the bulb, only the power of the traditional bulb which it is equivalent to. In other words, if a tungsten bulb is 100w and this... [Read more]
@xpatrik89 of course yes. That was a rhetorical question. I will add more - even if Chinese manufacturers give the "real" power of the "bulb", e.g. 12W, in practice it is often 9W or something. And... [Read more]
Well, here in the pictures - maybe not very intuitive, but it is stated that it is 15W and 1600lm -> for comparison, recently for ~ PLN 50 I bought a 15W from Osram (2500lm - I wanted a very strong light),... [Read more]
It's probably also a bit of marketing, 166lm / W in a boxed solution, taking into account the efficiency of the converter? [Read more]
probably yes, but it shines (very) noticeably stronger than others with a similar power rating (~15W) - I don't have a light meter, and the assumption of very good room lighting has been implemented... [Read more]
I have not measured the power consumption and I don't have the tools to do so. But the manufacturer claims that is a 100W equivalent bulb, uses 15W, and is a 1600 lumen bulb. It's a WB8P. More pictures: ... [Read more]
Thanks, I have added the extra information to the database. By the way, did the manufacturer "forget" to solder something here? https://obrazki.elektroda.pl/7023461500_1669877640_thumb.jpg [Read more]
I need some help figuring how to use openbeken. I used the tuya-cloudcutter to install the firmware. After adding the Wi-Fi credentials the bulb won't light up. I'm able to enter the config web and don't... [Read more]
Welcome to forum, @fierrote . The lack of RGBW controls on your main panel strongly indicates that you haven't configured your bulb yet. Can you try doing template extraction as on our video? Alternatively,... [Read more]
I went into the config and just pick my device from the drop list instead of input manually (because I'm lost) and it worked. Now figuring how to add it to HA. I install it in a QNAP NAS, but apparently... [Read more]