Jun 29, 2026, 8:40 PMHuh. I just bought something that came with a fake infrared remote.
It looks like one, but the LED isn't the usual IR, it's just plain red.
And the remote works even if that LED is blocked.
This is an RF remote! Not an LED remote!
Jun 29, 2026, 8:46 PMI mean, it's fine, it's not like the thing calls itself an LED Remote Control.
OH WAIT, YES IT DOES
Jun 29, 2026, 8:47 PMsee? LED. Right where an IR remote would have an IR LED
Jun 29, 2026, 8:51 PMAnd here's the LED. Not only is this visible to my Human Eyes (which can't see IR), it's the wrong color. This is not what IR looks to my phone camera
Jun 29, 2026, 8:52 PMHere's an actual IR LED remote shining in my camera. Notice how it's a shade of purple, not red?
Jun 29, 2026, 8:53 PMI pulled the cover off and OH HELLO
this remote has two "buttons" but pads for 21!
Makes sense, this remote is probably reused with a lot of things
Jun 29, 2026, 8:57 PMBlurry picture of the PCB.
Very minimal: a couple resistors and caps, an anonymous 14-pin microcontroller, two little mosfets, and a 433 oscillator. So this thing is a 433mhz remote
Jun 29, 2026, 9:00 PMIt looks like those mosfets are for the oscillator and the antenna trace, not the LED. Makes sense I guess, whatever MCU this is can handle a low-power LED just fine
Jun 29, 2026, 9:13 PMIf I'm using this SDR properly (dubious), it looks like it's using 433mhz channel 36, at 433.950khz
Jun 29, 2026, 9:32 PMI don't think I can decode or replay the messages it's sending with this specific SDR, I'll have to borrow a different one from my sister for that
Jun 29, 2026, 9:44 PMI googled it and found a couple other cases of people running into this kind of remote and getting confused because they're trying to decode the IR or replicate it and THERE IS NO IR, IT IS LIES
Jun 29, 2026, 9:48 PMit seems to be a clone of FCC ID 2AUSN-LXZK1021: LXZK-TX1021, a remote for lights, licensed in 2019
Jun 29, 2026, 9:50 PMhas anyone hacked the FCC and leaked all their confidential PDFs yet?
I'm not saying anyone SHOULD do that, or that I'm eagerly awaiting the collapse of the US government so that I can pick through the wreckage, but it would be nice for us reverse-engineers if someone would leak all these FCC PDFs that explain how shit works
Jun 29, 2026, 8:43 PM@foone and the LED is there to show you the remote has battery 🧐
@foone I've seen the BT "cable" trick, but not an actual remote yet.
@foone its a retro aesthetic
Is this the doing of @NanoRaptor ???
This is so janky. I'm invested now.
@foone average consumer finds 0 keyboards per day, Keyboards Alice is an outlier adn should not have been counted
@foone probably the kind of remote for a led strip with 1 button per color
@foone The real question is; do those other pads do anything?
Jun 29, 2026, 9:31 PM@RandamuMaki All of them transmit a signal, but the receiving device seems to only respond to the two main buttons
@foone technically speaking, 433 mhz radio waves are also below red in frequency ... on the other hand, I suppose an antenna and a diode are a bit different ... and red isn't infrared. I guess 1 of 3 is the best you can expect these days. But wait ... does 433 mhz make it a ham sandwich?
@foone oh you have a Malahit dsp2 :0
Why i am not surprised ? X)
(Was eyeing it and the tecsun for dipping my toes in radio listening).
Jun 29, 2026, 9:23 PM@Briarheart It's actually my sister's, I'm just borrowing it
@foone that explain what you said earlier x)
Well, wish you luck : I'll warm up the (metaphorical) popcorn.
Jun 29, 2026, 10:42 PM@foone @Briarheart
You clearly have a very cool sister :)
434 (and 868) MHz a re unlicensed bands in Europe.
@foone There is no IR, only Zuul
@foone sorry I'm not Gen X I'm trying to delete it
Jun 29, 2026, 9:48 PM
Jun 29, 2026, 9:52 PM@foone it would be nice, having the internal photos is certainly nice but oftentimes they're unconscionably bad and you can't make out the markings on chips
@foone they often leak it on their own. I've seen confidential PDFs in test reports open to the public...
@foone if you were given control of a federal agency of your choice what would it be, and why would it be the FCC?
Jul 1, 2026, 1:03 AM@ThatHumanBeing actually I've already answered this one before, and my answer was the United States Mint, because I have Ideas about how I'd fix the currency & coinage. well, "fix" is a strong word... "change" maybe.
https://bsky.app/profile/alice.averlong.com/post/3mowi7ucanc23
@foone I forgot about your Mint ideas, I was thinking about you like to take advantage of the airwaves whenever the FCC can’t get mad because of a government shutdown
@foone we recently ran into a pair of dimmable switches used for USB lights. The remotes have a working IR LED but use radio too. The receiver itself is not even capable of receiving anything optical. We just found out, when we noticed one light turned on when we switched the other, couple rooms apart.
Jun 30, 2026, 12:01 AM@foone a flipper might be able to decode it.
@foone I bought some lights similar to this and also went looking for ways to decode and replicate the remote & it looked spotty but maybe possible. I’ll admit, I was also mad that it wasn’t IR -_-
Jun 29, 2026, 10:00 PM@foone I made an RFLink adapter for my homeassistant setup and it listens for and can emulate a lot of remotes in 433Hz, though actual reception/transmission can be hit or miss.
I've captured and replayed several with my flipper zero as well.
@foone i'm not seeing how to non-destructively open the case to see if this is the same board, if not must be a close relative of your remote. tested it's IR by holding my finger over it too.
Jun 30, 2026, 2:24 AM@foone That is, BTW, likely not an MCU. IR-Remotes tend to have tiny ASICS for the job. After all all it does is determine what button in a matrix is pressed and then send a data-word in one of the few standard formats like RC5 or NEC something.
Jun 29, 2026, 9:00 PM@foone what surprises me there is a real chip instead of an epoxy blob even if the identifying material has been lasered off
Jun 29, 2026, 9:05 PM@foone It seems like the sort of thing one does when one has already told everyone it's an IR remote, but got a really good deal on these RF components that yielded a better ROI, and didn't want to waste perfectly good marketing materials.
@foone 433MHz crystals don't exist, looks more like a 433MHz SAW band pass filter to me.
@foone ee gads the hand made circuit board. rivet vias, giant blobs of solder. Some poor fucker with a soldering iron made that abomination. Probably next to a bowl of acid to do the board etching too. :|
@foone Ha! You have an example of "FCC hacking", everything says it is an LED remote, and look even the LED lights up when you push it. But its *really* a 2.4GHz remote without any FCC certification because that would be expensive and make importing it hard to do!
@foone Of course its possible that its *even jankier!* That's right, it could be a small CPU that is doing an AM broadcast. 😃 Would be interesting to wave an EMC probe over it while pushing the button.
Edit: Alas with a 433MHz crystal, it would be using that frequency. Looks like a single pin driving a P-FET/N-FET half bridge so it could use an arbitrary protocol. That also works at 1.3GHz 😆
@foone Huh.
I have several of these, but IR, and always slightly wondered about the weird button placement. But, yeah, that makes total sense, and explains why on/off aren't just 0x01/0x00 IR codes but weird unrelated 0xAC and 0xB3 or whatever.
@foone This is pretty clearly the exact same PCB from the remote to the LED lights my ex put up in her basement, which I want to say used all of those pads (but maybe "only" 18 of them? It's been a couple years)
The funny thing is, that LED remote control for actual LEDs *did* use an IR light to work.
@foone which come to think of it I'm pretty sure I only know because I liked to set 2/4 in the main room magenta and 2/4 the lightest blue on offer when it was time to do our shots every week, and to get them to behave I had to block the periphery of the IR LED or else it'd just full-blast every light in the room (or more often, exactly three of them)
@foone I genuinely feel bad for every piece of electronics you own. At any given moment, each one could be ripped open for no reason. I only hope you are as better at putting them back together than I am.
@foone SECRET QUANTUM LEAK. ON OFF AND MANY OTHERS.
Jun 29, 2026, 10:00 PMJun 30, 2026, 12:01 AM@foone other buttons not valued? Internal mechanism for making golden buttons? It’s late, sorry.
Jun 29, 2026, 8:54 PM@foone I've seen some old (actual) IR remotes that also had a red LED near the IR ones to show that it's actually doing something when you press a button. Maybe that's their idea?
@foone that is a GORGEOUS colour…
I want earrings/paint that colour
um. ... if it has RF why ... I feel like I'm missing something .... why does it have an LED?
Is it just for fun? For the form factor? Why?
Jun 29, 2026, 8:54 PM@futurebird @foone I assume so that folks who think remotes have lights will buy it.