Hey, I just moved to Vancouver so I needed some under cabinet lighting for the kitchen. Imagine my delight when I saw Battery Operated Closet Lights on the e-waste shelf, with batteries just beside them! Little did I know this was going to be a misadventure in circuit hacking.
I installed them but the problem was, they only mostly sorta worked during the night. During daytime, even though the kitchen is a bit dim, the motion sensor didn’t trigger at all, so we wanted more light and didn’t get it.
Searching for “BR0020A1” didn’t turn up much, I heard the e-waste pile is Amazon returns, and even searching there didn’t find it. But it did turn up this pdf manual: https://m.media-amazon.com/images/I/B1TopJT8eXL.pdf Alas, there’s no way to adjust the sensor.
So, I guess the universe was telling me to take them apart.
It’s an IR sensor + microcontroller. Nothing crazy.
IR sensor part number is S23-S330Y. Pretty hard to find docs for it, the mfg is cagey and requires you to contact them (which went unanswered): S23-S330Y mini SMD AD PIR sensor-HJP Sensor | Gas Sensor manufacturer | Pyroelectric Infrared Sensor Supplier But a friend (from Montreal hackerspace foulab.org) managed to find the datasheet in Chinese actually: https://www.nysenba.com/static/upload/file/20251216/1765863194995099.pdf
Waveform is pretty funky, some kind of custom framing followed by PWM-coded bits:
Trouble was, when the IR sensor is in full light, the signal goes completely silent. Hmm what to do what to do. I tried to cover it with black electrical tape, still silent. Hm, weird.
Then I shifted my attention to D1 in the circuit. What could that be? The LED never turns on. Oh wait! What if it’s used as a light sensor to suppress the IR sensor during high light conditions?
And that was it. After putting a tiny patch of black electrical tape on D1, the lights work well, even in daylight, in our kitchen!
I spoke to someone last Tuesday, just before the battle bots event, who also grabbed some of these lights for their closet, and wasn’t happy with their sensor. I think his name was Bill (or Bob maybe?) and he wanted to know if I ever found a fix. He was the participant wearing the cowboy hat during the bot battle. If anyone knows his handle on here, could you please tag him?
Happy tinkering!