LittleBits puzzle - part 4

Hi all,
The 3th puzzle puzzles everyone it seems.
But don’t give up yet !
And @JackANDJude requested a new one, so here it is !

So, what we want to create is a device which can switch our christmas tree :evergreen_tree: on at random.
The on - off cycle is constant, but the on time is random.
This on time could be easily 2 minutes or more.
We can only use 8 bits, including a power bit and output bit.
And as always - no arduino bit :grinning:

Good luck !


Hi all,
It seems that we can downsize the number of bits to only 5.
Any ideas yet ?
The Christmas tree awaits !

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I’m gathering Bits (ones I think you would pick) and my gut tells me there are a few solutions…

Ok @Frankje here is my attempt. The led’s and number Bit are for the viewer to get what is happening. I really used

power + oscillator + random + timeout + pulse + latch + ir transmitter

I tried all my bits, exept the home-automation switch which cannot be activated here in Europe.
I must give up. But curious about the solution. :grinning:

Hi @alexpikkert and @JackANDJude and everyone trying to solve this puzzle.
The Christmas tree in the movie clip seems to light on and off randomly, that’s correct.
But the trick lies in the fact that it might lit after a reasonable long time (2 minutes or more), so the timing needs to be longer.
Ok, here’s a clue :smile:
We need the number bit to adjust precisely the right amount of voltage.
Once it has been set, the timing is correct and the number bit can be left out.
And JackANDJude, your setup is almost correct. There is a crucial bit missing that takes care of the right amount of voltage.
And Alex, I use a step down converter from 220 V to 110V to use the infrared receiver. The Christmas led lamps work with this voltage.
Might be a good idea to hack this IR receiver to work with 220V .
I will post the solution in the weekend if you want, keep on trying !


Hi Frank @Frankje ,

I opened the IR receiver/switch a long time ago.
Two issues came up:
The housing has typical USA plugs. No way to alter them into European version without demolishing the housing.
Littlebits design team also did never plan to introduce a European version. The electronics work on 110 V AC only, I did not see a solution to increase this to 240V AC without changing major parts like the switch relay etc.

I am using another receiver make ETM (it is sold as a stand-by off switch for a TV)
It can learn the Littlebits IR sender code (and any other remote control) but it is designed with a standard time delay of one minute after switching on before you can switch off again. So no blinking christmas tree… :evergreen_tree: :cold_sweat:


Hi @alexpikkert

Don’t give up yet, since you can still use a led bit to make the output visible.
You could always use a few led bits in a small Christmas tree :sweat_smile:

I will give it a try for the IR receiver module.
We could always use a USA to Europe plug.


Hi @alexpikkert and @JackANDJude and everyone reading this,

Here’s another clue to solve the mystery : We need following bits to make the circuit work :smile:
Pulse bit, output bit ( LED, IR receiver, Number bit, …), power bit, threshold bit, random bit.
Put these together in the correct order with the correct setting et voilà :smile:
Ans as mentioned above, you need the number bit to make fine adjustments !

Good luck !