Playing around with Beethoven

Ruebezahl

Ａ few months ago, when i was shopping for electronic parts, i saw a chip that had written "music playback" in the description, so i got curious and found a datasheet. H66T19/32/68

Turns out it's a chip that sole purpose is to play back a certain song, that's already saved on the chip. It comes in three different versions, with different songs saved on it. The one on sale is playing beethovens for elise. I was not sure if i could do anything interesting with it, but the fact that the company is called "Hi Sincerity Microelectronics" and that the chip sold for 1 dollar for 5 pieces, i couldn't resist. Laughing

Today i finally found the inspiration to play around with it, and although the datasheet mentions a rythm generator, it seems like there is not much you can do with that, or any way to reprogram the chip. At least i got to change the pitch, when dividing the voltage between the recommended supply voltages. I guess that already gives some ways to play around with modulating the supply voltage, feeding it a triangle LFO or something.

But beyond that i don't really know what to do with it, maybe put it into a toy garbage truck Razz

(Sorry this one need some background: In Taiwan, where i live, the garbage trucks play this song to signal it is time to bring out the garbage. i actually suspect that is the purpose of this chip, i just wonder what the other two versions are for, but maybe that's the reason this shop only sold this one)

fuer elise.mp3

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playing around with beethoven

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wakyct · Posted: Sat May 21, 2022 11:33 am Post subject:

I don't have much to say except I enjoyed your post Smile

. But it does make me curious, is it hard to obtain the programmer used for these chips? Could you potentially decompile the source on the chip? Just some random thoughts...it seems like a fun puzzle.

Ruebezahl · Posted: Sun May 22, 2022 8:26 am Post subject:

Thanks! I would love to get some more info on this chip and how to be able to control more than just the playback speed, but the datasheet is not very helpful on that... Also it just has three legs, maybe you would have to send the input some special serial code to be able to control it, but no idea how that should work. Anyway i tried modulating the supply voltage with a triangle wave, which works pretty good, but it also get's old quickly. Maybe next step would be to somehow divide the output with a 4040 and mix the outputs together, or juggle them around with a multiplexer, let's see!

btw, here is a video of the garbage truck in Taiwan:

https://www.youtube.com/watch?v=pnboehFdHFI

Für_elise_mit_modulation[1].m4a

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