Comment by josephwegner | Hacker News Reader

Comment by josephwegner | Hacker News Reader

I have a silhouette cameo pro 4 (and love it), and have been wondering around similar things. The Cameo can only be controlled via the provided software, or a couple proprietary plugins for popular design software.

The provided software is clunky, and the plugins suck. I’ve been building an app for designing stickers, and what I really want is to either be able to drive the Cameo from the app directly, or output a design file in a format that can be loaded straight into the software to start cutting.

The thing I’m stuck on is… how do people reverse engineer these devices protocols, without fear of bricking the device? My understanding is that reverse engineering like this is a lot of “try shit and see if it works”. It seems to me that a few wrong commands could get the cameo in some irrecoverable state. Obviously that’s not a risk I’m willing to take on a machine I use very regularly.

I don't have a Cameo Pro 4 to test, but I have reverse engineered software to control some of their other devices. It's a little janky but if you want to help I'd appreciate it!

https://robocut.org/

I believe there is (or once was) also an Inkscape plugin somewhere but I never tried it.

As for how I reverse engineered it, I just used a USB sniffer and wireshark. I don't think there's a big risk of bricking these devices - I don't think they even have non-volatile storage, so worst case you turn it off and on again.

I would like to reverse engineer my solar power inverter too, but that is definitely brickable (the first one they shipped me came pre-bricked!) and is a lot more expensive so I've had to resist. :/

You disassemble and analyze any software you have access to, and then you put Wireshark in between the software and the device. You watch the bytes being sent to the device and trace their path backwards through the software. Eventually patterns become visible and you can start making guesses about how things work.

Cameo -> inkscape plugin => https://github.com/fablabnbg/inkscape-silhouette

"""Run sendto_silhouette.py --help for information on CLI usage."""

I've used it before (from the inkscape-plugin gui, not tried the CLI version). Typical open-source "slighly janky" (at least ~5 years ago...), but very serviceable and convenient to work with, hopefully only getting better over time!

I mostly deal with the possibility of bricking a device by not caring too much :) That said, I usually start by reverse-engineering the software at one of the ends, so I don't blindly "fuzz" the device. There's still some risk, but not that much.

I always used to export from inkscape to the silhouette software.

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