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Dag Ågren ↙︎↙︎↙︎'s posts Post Back to profile
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Dag Ågren ↙︎↙︎↙︎

For the technical details, it's built around a Sipeed Longan Nano microcontroller module, connected up to a small amplifier, some little pill box speakers, and a bunch of microswitches. The microcontroller itself is a GD32VF103, a weird Chinese creation of dubious legality that stuffs a RISC-V core into a clone of an STM32F103 to replace the original ARM core.

It's pretty fast, and can run the built-in tiny LCD at 60 FPS along with 10 voices of Karplus-Strong synthesis.

23 May 2022 at 23:21 | Open on mastodon.social
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Dag Ågren ↙︎↙︎↙︎

I love the Karplus-Strong algorithm, it is a completely bullshit way to simulate a stringed instrument cheaply: en.wikipedia.org/wiki/Karplus–

It can be a bit tricky to tune that algorithm since in its simplest form it can only be tuned to integer divisions of the audio frequency. Using just intonation helps here!

23 May 2022 at 23:23 | Open on mastodon.social
Dag Ågren ↙︎↙︎↙︎

The sample rate is 48000 Hz, and the "strings" are tuned to that divided by 54, 64, 72, 81 and 96, and then double those.

23 May 2022 at 23:26 | Open on mastodon.social
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@WAHa_06x36 Thank you very much for sharing this. I love that you're providing details about the implementation and design decisions. 👍

24 May 2022 at 4:58 | Open on digitalcourage.social
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@WAHa_06x36

Oh look, people trying to take credit for functionality to adapt for what's not theirs.
24 May 2022 at 6:45 | Open on fr13nd5.com
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