bunnie's blog

The Ware for December 2025 is shown below.

This is just one part of a much more complex ware, but I thought I’d throw just this photo out there for starters because it’s one of the more thought-provoking portions of the ware.

Super curious to see what people come up with! If nobody guesses it off the bat, I’ll add some more hints in a couple of weeks.

Happy holidays!

The Ware for November 2025 is a controller from the card-activated power switch in a hotel room. It was on the fritz, and when the repair person came and replaced it, Sam asked for the old module and brought it to me as a name that ware entry. Here’s the other circuit board that was mated to the controller: basically a big relay that can cut power to the room when the card is pulled out.

I’ll give Greg the prize, since he was the first to basically guess the ware. However, I never considered the possibility that the snap-action switch could be an anti-tamper mechanism. Maybe that’s what it is for? My assumption was that the switch is what’s used to turn on the RFID circuit to check for the presence of an RFID antenna. Given the simplicity of the components and the lack of an obvious way to synchronize the card’s code to a central server, I actually suspect the device can’t even read the card: it just checks for the presence of a tuned RFID load, so that you can’t keep power on in the room by jamming a random business card into the slot.

The Ware for November 2025 is shown below.

This one is hopefully a bit easier to guess compared to last month’s ware! Pictured is just one board of a two board set, but the second board is a bit too much of a dead give-away so it’s been omitted. Thanks to Sam for thinking on her feet and snatching this board so that it could be donated to the contest!

Last month’s ware is an ADAS1010, described on the Analog devices website as a “15 Lead ECG Vital Signs Monitor Module with Respiration, Temperature and Blood Pressure Measurement”. It advertises a “robust, with electromagnetic interference (EMI), shock, and vibration resistant packaging”.

This is one of the more over-engineered solutions I’ve seen. I’m guessing that the middle layer of the three-layer stack is probably hollowed out, such that the surrounding boards create a Faraday cage. This would allow sensitive ECG front-end circuitry to be placed inside a shielded “container” that also doubles as a connector between the front and back boards.

This one was a real stumper, and it was interesting to see the discussion. I had redacted the DSP’s part number – ADSP-CM403 – because with that, an LLM could identify the board with a query such as “what boards have both an adsp-cm403 and an ice40 fpga”. That’s apparently a pretty unique part combination. When I saw it for the first time, I also couldn’t guess the ware; I kept on looking at the huge connector and assuming that some high-bandwidth, high-speed signals were involved. That’s an awful lot of pins for the advertised functions, but probably an insane amount of grounding/shielding is going on to isolate the sensitive ECG input lines.

I was betting the boards near-exclusive use of Analog Devices parts would be a tip-off that this was an Analog Devices module of some type, which would significantly narrow the space of possible functions. You kind of have to be on a very particular mission and/or have an unlimited budget to end up integrating that level of ADI parts on a board if you’re not actually ADI. To that end, megabytephreak got dangerously close to guessing it, so I’ll declare megabytephreak as the winner. Congrats, email me for your prize!

The Ware for October 2025 is shown below.

Thanks to Juan C. for contributing this curious ware!

I really can’t get enough of how the whole device is integrated with a multi-layer stacked PCB. I imagine that inside the middle of the stack there could be some interesting circuitry going on, too.

I redacted one part number to try and make things a smidge more challenging; at least, an LLM wasn’t able to outright guess the ware when that part number was omitted (but of course, the spirit of the game is to sharpen the wetware sitting on your shoulders by trying to reasoning about the function of the ware, with the aid of reference searches to find datasheets, learn theory, etc).