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Comment by SaberTail | Hacker News Reader

> The "Status" LED flashes some kind of code - long long, short short short. I assumed the number of flashes would correspond to the time but apparently not. We didn't have time to figure this out before we had to leave.

long-long-short-short-short is 7 in morse code. They don't say what time they tried this or if it ever changed, though, so that's just a hypothesis.

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As an engineer i would never think that complicated - morse code?

Couldn't it be just binary

long-long-short-short-short

11000

Which is - to everyones surprise - 24 as in hours.

To anyone other than a computer engineer, I would bet Morse code would be preferred at least 10 to 1. Most people who aren’t computer science majors could barely decode binary “10” correctly, whereas writing down the dots and dashes and googling “Morse code chart” is something I’d bet over 50% of non-engineers could do accurately.

How is this any different than decoding binary? If you can read a chart of codes involving either dot or dash surely you can also read a chart of codes with either 0 or 1.

It's not so much that it's different, it's just that Morse is the canonical dot-dash/beep-boop communication format in the UK, and binary is a niche distant second known only in the abstract as "it's all ones and zeros" to most non-tech people. So while an engineer would expect a beep-boop to be binary, a police station caretaker would expect it to be Morse, and I'd expect the people building that system to build it for the caretaker.

I had that thought too when I saw the parent comment earlier, but then I looked up the Morse code digits and I have to admit that they are much easier to decode from a flashing light than binary and I'm pretty good doing binary in my head:

    ----- 0000
    .---- 0001
    ..--- 0010
    ...-- 0011
    ....- 0100
    ..... 0101
    -.... 0110
    --... 0111
    ---.. 1000
    ----. 1001

Also, if I see a light with short and long blinks and a pause in between, I'm going to immediately think Morse, not binary, and decoding it is almost intuitive.

It's almost certainly this. I suspect the advance button can be used to advance the time via morse code LED flashes and only then committed when you get to the right hour.

Perhaps the long-press commits the hour, which is why it rang once initially.

I used to use Morse to blink out status codes in similar things but I think by the mid-2000s I'd moved from PIC16F628s to atmega328.

I didn't build the chime box but it looks like the sort of thing I used to do back then.

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