High Voltage Forum

General electronics => Electronic circuits => Topic started by: profdc9 on September 15, 2018, 10:55:33 PM

Title: Theremin based on the stm32f103c8t6 and bluepill, stm32duino
Post by: profdc9 on September 15, 2018, 10:55:33 PM
Hello,

I made a theremin based on a STM32 microcontroller (the $3 bluepill).  You can see me play it in this video

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The theremin as you can see is quite sensitive.  I actually put a fiber optic output on the board so I can program it to be an interrupter for a DRSSTC.

The parts are very inexpensive and the circuit is fairly simple.  The PCB, schematics, and the software are on a github

https://github.com/profdc9/MCTheremin

If you want to try to build it let me know.  Enjoy!

Dan


Title: Re: Theremin based on the stm32f103c8t6 and bluepill, stm32duino
Post by: futurist on September 17, 2018, 08:57:40 PM
Nice job! Do you think it would be possible to omit external DAC if using STM32F103Rx series? That would also be a nice upgrade to gaudi's opentheremin v3
Title: Re: Theremin based on the stm32f103c8t6 and bluepill, stm32duino
Post by: profdc9 on September 18, 2018, 05:00:57 AM
I would consider using the STM32F103Rx series if there was a convenient, cheap board like the bluepill you could buy.  The bluepill is $3 on ebay.  It's still much cheaper to use that and a MCP4921 (1.25 USD) than almost any other dev board.  The tinnitus32 theremin (https://github.com/gerdb/tinnitus32) - by the way this is an AWFUL name for a device that is supposed to sound pleasant - uses the STM32F4 but isn't terribly convenient because it doesn't really have a PCB to integrate everything into, though such a thing is possible for the STM32 discovery board.  A form factor like the bluepill or Arduino Nano is very convenient for integrating into projects unlike a whole dev board, though a dev board could be integrated into a project like the OpenTheremin does.

Dan

Title: Re: Theremin based on the stm32f103c8t6 and bluepill, stm32duino
Post by: futurist on September 25, 2018, 04:00:31 PM
I thought I saw high density STM32F103 demo boards on ebay for 5-6 $, but it turns out that mcu is medium density so no embeded DACs

STM32F407VGT6 boards sell for 8 $, and since I purchased theremin parts on lcsc using demo board would even be cheaper overall (MCP4921 was around 4$ each on lcsc)
https://www.ebay.com/itm/STM32F407VGT6-STM32F4Discovery-ARM-Cortex-M4-32bit-MCU-Core-Development-Board/282538210960

I wonder if anyone built tinnitus theremin, couldn't find anything on the internet  :)