Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

I bricked my Christmas lights

whizzy.org

Post reply on HN
Print view View original

21–30 of 85 posts

Re: I bricked my Christmas lights

#21

Post by eichin »

syntaxing wrote: post #17

Beginners question, is there a reason we can’t reverse engineer something similar for lights made by Govee? Is it because it’s WiFi and harder to MITM?

There may be an easier way, but another HN thread pointed out that you can use tailscale to make it easier to tcpdump phone apps (because you can send all of the phone traffic through an endpoint you control.) (Presumably raw wireguard is enough? I haven't tried (or seen tutorials for) either approach, it was just a "that sounds clever, save it for my next sniffer project" idea)

Re: I bricked my Christmas lights

#22

Post by mrb »

MarkusWandel wrote: post #8

Power supply failure? The WS281x things can go really bright, and, in bulk, suck an awful lot of current. A 12V, 3A power supply on a strip of 100 is just about enough to drive them all to full bright white, and dazzlingly bright it is. So I'd look for a blown fuse. The fact that the firmware only drives them to 31 out of a possible maximum brightness of 255 offers a clue.

That was my first intuition as well, seeing the brigthness limited to 0x1f. With any luck, the power supply might have a fuse, and it's just the fuse that blew up.

Anyway, if you can't salvage it, standard WS281x LED strings can be hooked up to a Raspberry Pi and you could use my open source addressable LED controller :) https://github.com/mbevand/ledthemfight It comes with built-in effects. I made it very modular so for the DIY crowd, in 2 lines of Python, you can create simple custom LED effect modules. See a demo here: https://youtu.be/qpd2rILsnM4

Re: I bricked my Christmas lights

#24

Post by brk »

syntaxing wrote: post #17

Beginners question, is there a reason we can’t reverse engineer something similar for lights made by Govee? Is it because it’s WiFi and harder to MITM?

I like the form factor of some of the Govee string lights. I’ve thrown out their controller and hooked them to ESP32’s with WLED. Best of both worlds that way.

Re: I bricked my Christmas lights

#25

Post by sva_ »

willcooke wrote: post #2

I was trying to automate my BLE connected Christmas lights but instead I created e-waste. Now you can too!

Not sure what you did with it, but I found that some of this SmartTrash does a hard reset when you do some magic sequence such as quickly turning if off/on 5 times in a row.

Re: I bricked my Christmas lights

#26

Post by kordlessagain »

ww520 wrote: post #16
Someone wrote: post #4

FTA: > When we try and decrypt the on and off packets we get: > 05 54 55 52 4E 01 00 00 00 00 00 00 00 00 00 00 > 05 54 55 52 4E 00 00 00 00 00 00 00 00 00 00 00 > 05 54 55 52 4E 01 00 00 00 00 00 00 00 00 00 00 > 05 54 55 52 4E 00 00 00 00 00 00 00 00 00 00 00 > 05 54 55 52 4E 01 00 00 00 00 00 00 00 00 00 00 > 05 54 55 52 4E 00 00 00 00 00 00 00 00 00 00 00 > Success! This is a lot more sensible. A fixed header, by…

That's a great catch. 0x54 55 52 4E indeed are T U R N.

Turn off the wifi.

Re: I bricked my Christmas lights

#27

Post by elliottkember »

willcooke wrote: post #6
CTOSian wrote: post #3

Earlier quoted context omitted.

you can still use them as dummy/classic lights if you bypass the controller

+1 I can just swap the micro controller with something like an ESP8266 and run WLED.

If you get into FastLED, try out the emulator I made – https://editor.soulmatelights.com/gallery/732-rainbow-conway

I haven't worked on it at all recently (COVID project) but it's fun for experimenting. You can also flash ESP32s from the downloadable desktop app

Re: I bricked my Christmas lights

#28

Post by echelon »

I'm looking for some flexible, robust lights for my car's roof rack. I'm wondering if anyone knows a set that will fit these requirements:

  - Battery powered and outdoor / all weather compatible

  - Easy to attach the battery box to surfaces using ties

  - Ideally "mini" form factor ("T5") [1]

  - Ideally RGB and programmable. I'd like to use them for 
    Christmas (red/green), Halloween (purple/orange), and 
    other seasons.
Does anyone know of anything that fits this bill? I've had trouble finding anything that fits the last criterion. Walmart and Home Depot will sell the first three.

When I search for this, I just get noise.

[1] https://cdn.christmaslightsetc.com/images/CategoryDetail/788...

Re: I bricked my Christmas lights

#30

Post by jonhohle »

willcooke wrote: post #5
Someone wrote: post #4

FTA: > When we try and decrypt the on and off packets we get: > 05 54 55 52 4E 01 00 00 00 00 00 00 00 00 00 00 > 05 54 55 52 4E 00 00 00 00 00 00 00 00 00 00 00 > 05 54 55 52 4E 01 00 00 00 00 00 00 00 00 00 00 > 05 54 55 52 4E 00 00 00 00 00 00 00 00 00 00 00 > 05 54 55 52 4E 01 00 00 00 00 00 00 00 00 00 00 > 05 54 55 52 4E 00 00 00 00 00 00 00 00 00 00 00 > Success! This is a lot more sensible. A fixed header, by…

Oooh! Good spot. I will check other commands and see if that length idea works out. I think it could.

That’s pretty typical of binary formats. That and offsets or addresses. And type tags. Assuming the payload isn’t compressed or encrypted, you can get pretty far assuming you’ll run into one of those eventually.

Anecdotally, earlier today I was trying to decipher Encarta data and came across the “Mind Maze” data and it’s mostly that - fixed 32-but header, question size, (answer size, answer, correct flag, something I haven’t figure out yet){4}. Then a separate file with an index value and an offset into the first file as well as a header I haven’t figured out yet.

Post reply on HN