alt Hacker NewsResponding to you and @thewhitetulip
If you ask Claude how to do it, it might already give you some strategy that's reasonable (at least, it's good to see what it thinks)
Make sure to use Fable, and preferably have the Max plan (or plenty of credits)
LLMs can do very good work when they're unattended and optimize towards a goal that's unambiguous / for which you have a reference.
Generally speaking, in hardware, this means having a "rig" ie a testbed where the AI can send commands, observe output, and iterate on its own. You want autonomy, not babysitting (as much as possible)
In the case of this Casio watch, I would start by giving Claude Code context on what you're trying to achieve (read&decode messages sent probably over BLE, reverse engineer the protocol, get to a point where it can send valid messages itself). The goal should be a python/command line tool that can sniff packets, decode them, and send them. (step by step, starting with sniffing)
Get the nRF52840 USB dongle mentioned. Have Claude Code talk to the dongle. Ask it to list devices it sees. Ask it to see/detect the Casio watch. Use the proprietary Casio app and ask CC to record the sequence and decode the messages (explaining to it what you did in the app)
Also: have it do research - has this protocol been cracked/documented before? Is there an Android app for this Casio app which could be decompiled (usually more easily than the equivalent iOS app)?
Reach out if I can help - my offer for a dongle stands for anyone who wants to do this! It looks like a cool watch, it shouldn't be held hostage. :-)
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From my experience Fable will reject this request - its pretty trigger-happy with it's safety detector for reverse engineering, even if you push it on right-to-repair. However Opus 4.8 is more than capable of doing it, with a bit of guidance.
Hi Greg, I am Claude Code junior specialist from Czech Republic and also huge Casio fan. I've been ignoring all bluetooth enabled models in the past, since I had a lot of negative experience with proprietary apps (Sony Music Center, Ultrahuman etc). This is not me first time thinking about reverse engineering products app, I love open hardware and I wanted to contribute to the community, but while doing my research (which Claude agrees with), I've figured out that it might not be as easy as I thought. For example, Googles Fitbit Air is according to some encrypting its traffic in a way, that it reaches Googles Cloud first, unencrypts and then reaches the app itself. How would you approach this issue? By the way, the dongle offer still stands? ;)