[Projects] DIY Dashcam update

Alright, that was a lot of soldering and it’s not perfect, but I’m not either. So with that done, I have bolted on the PiSugar auxiliary battery and I think it is time to plug in the camera as well. Now I do hope that I find that one github thing back where all the code was!

Back soon with more progress! (I hope)

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Side-project: I’ll just build my own dashcam.

While I am trying to repair the Koonlung K1S Dashcam, I am going to build my own dashcam. Sure, I can buy one and pay a ridiculous amount of money for a half-way decent one, but I paid € 230 for the K1S which I assumed did not turn out to be trash.

And so, I am going to build one myself and learn from it in the process. The project was first going to be a pwnagotchi, but I think building a dashcam is more useful. For now @_@

While I am waiting for the auxiliary battery, I will have to start with soldering the 40-pin header onto the board. And if you wonder why I didn;t buy one with a header soldered on it already, my answer is: “I had no idea that this was an option!!1 D: ”

A box of parts that will become a dashcam at some point. There is a raspberri Pi Zero board, a E-Inkt screen, a clock timer, a camera and some wiring
The box of stuff!

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Trying to fix a Koonlung K1S, a probably long-term project. [plus downloads]

The Koonlung K1S is a very nice dashcam, with GPS, emergency button and HD recording and everything is made quite small. The HD video has a bit of a low bit rate, but it’s still not bad.

That said, it became a piece of rubbish. No matter what kind of SD card is inserted, the software locks up and the whole device becomes useless.

The front side of the Koonlung K1S Dashcam
The Koonlung K1S Dashcam

I have tried all the versions of the firmware [⇓1]. I have tried to decompile the firmware [⇓2][⇓3]. Nothing worked, whatever I tried.

So the time has come to take the thing apart. It cannot be any more broken than it is now, so maybe it is a blown cap or something? It is not, by the first look. There seems to be a corroded button cell soldered onto the motherboard.

The close-up of what looks like a small button-cell battery
Hmmm, is this a corroded button cell?
Probably a corroded button-cell
This seems to be at least a problem.

Alright. So what model is it? It’s not like you can just take it out and read what’s stamped onto it. Luckily I have a reference sheet in my archive that can be helpful. Hooray for being a data hoarder? >_>

The diameter is 4.8mm and the height is 2.0mm. The height is somewhat debatable as everything is small and kinda hard to reach. According to my datasheet, there are two candidates as a replacement battery:

  1. 4.8 x 2.15 – 1.55V – Maxell model: SR421SW – Seiko SB-A6 – Citizen 280-77 – GP 348
  2. 4.8 x 1.65 – 1.55V – Maxell model: SR416SW – Seiko SB-A5 – Citizen 280-75 – GP 337

As I want to get the exact battery, I grabbed a mini caliper and measured 1.65mm. There we go. It will be a SR416SW or anything compatible.

€5,46 has been paid for a set of 10 batteries because it was impossible to buy just one and now it is time to get the battery out.

More progress updates later!


[1] K1S-R158-50417-MPHK1S-R179-50825K1S-R180-KPHK1S-R180-MPHK1S-R215-KPH
[2] k1s.bin_hlil – Type: Mapped, Platform: thumb2, Architecture: thumb2
[3] k1s.bin_hlil-arm7 – Type: Mapped, Platform: armv7, Architecture: armv7

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