Is the Cree A21 really a 100 W LED bulb?
No. “100 W” refers to incandescent equivalence. The LED driver consumes 15 W while delivering 1 600 lm, matching a 100 W tungsten lamp’s brightness [Elektroda, etnguyen03, post #20312256]
[BK7231T] Cree A21 100W RGBCW bulb
TL;DR
- Teardown shows the Cree A21 100W RGBCW bulb uses a BK7231T Tuya chip and can be flashed with OpenBK7231T.
- The bulb is sold in the USA for $13 on Amazon, Lowes, and Walmart, and its pin config includes P7, P8, P9, P24, and P26 for PWM channels.
- DIY smart-bulb tinkerers and firmware modders can use this guide to identify the hardware and prepare it for custom firmware flashing.
- Flashing requires soldering to 3v3, GND, TX1, and RX1, then holding CEN to GND to enter flashing mode.
- Opening the bulb needs careful prying with a razor blade and thin metal tool, and the screws on top are not useful for removal.
This is a short teardown of the Cree A21 100W tunable white + color changing bulb. It is sold in the USA and is currently $13 on Amazon, Lowes, and Walmart.
The bulb uses a BK7231T Tuya chip.
Opening the bulb: take a razor blade and insert it between the top plastic and the base. Then once you have a razor blade inserted, you can stick in a thin metal pry tool and carefully pry the top off.
Then, use the razor blade to pry off the bottom metal part, and then move the live wire out of the way.
Back to the top of the bulb now, the screws are useless -- don't bother removing them. You want to pry the entire board up and out of the housing. Once you do this, the board with the LEDs and the controller separates easily.
Installing OpenBK7231T: solder wires onto the 3v3, GND, TX1 and RX1; connect those to a UART and then follow the flashing instructions. You will need to hold a wire connecting CEN to GND to get the chip into flashing mode.
The pin config is:
* P7: PWM, channel 4
* P8: PWM, channel 5
* P9: PWM, channel 2
* P24: PWM, channel 1
* P26: PWM, channel 3
(First post here, did I do anything wrong? Sorry if I did!)
The bulb uses a BK7231T Tuya chip.
Opening the bulb: take a razor blade and insert it between the top plastic and the base. Then once you have a razor blade inserted, you can stick in a thin metal pry tool and carefully pry the top off.
Then, use the razor blade to pry off the bottom metal part, and then move the live wire out of the way.
Back to the top of the bulb now, the screws are useless -- don't bother removing them. You want to pry the entire board up and out of the housing. Once you do this, the board with the LEDs and the controller separates easily.
Installing OpenBK7231T: solder wires onto the 3v3, GND, TX1 and RX1; connect those to a UART and then follow the flashing instructions. You will need to hold a wire connecting CEN to GND to get the chip into flashing mode.
The pin config is:
* P7: PWM, channel 4
* P8: PWM, channel 5
* P9: PWM, channel 2
* P24: PWM, channel 1
* P26: PWM, channel 3
(First post here, did I do anything wrong? Sorry if I did!)
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]