EuroPi VS MicroPython

Hi all, I'm making a Eurorack sequencer module with 4 pitch CV outputs (NOT audio) and I've noticed that DACs are kind of a pain due to being expensive, SMT-only & still requiring buffering with op amps. I figure that a good alternative would be to buy a Raspberry Pi Pico for $4 which will give me 8 PWM outputs that I would then hook up to an output stage like the one in the europi (shown here: https://github.com/Allen-Synthesis/EuroPi/blob/main/hardware/EuroPi/schematic/europi_schematic.pdf)

Bom has links for sourcing parts

Up until now I've been using the analog input stage from the EuroPi schematic as my model for a CV in. You can see it here:

There is no super cheap way to get a lot of analog outputs from an MCU. Filtered PWM is your best bet for cost effectiveness (I recommend looking at the EuroPi from allen synthesis : https://github.com/Allen-Synthesis/EuroPi). Otherwise if PWM doesn't work for you, you'll need to look into DAC chips. The MCP4728 is a good spot to start, it's 12-bit and has 4 channels: https://www.adafruit.com/product/4470. Since it's I2C controlled you can have multiple of them on one bus. Maybe looking into a 16 channel PWM driver for a lot of outputs: https://www.adafruit.com/product/815. Hope this helps!

The project is completely open-source and open hardware, and the contributors together have made this big list of scripts that you can run using a menu system!

The project is entirely open-source but I do also sell the Panel+PCBs on my site!

Check out the EuroPi project https://github.com/Allen-Synthesis/EuroPi

EuroPi Turing Machine script is feeding the Uncertainty cv input with pulse 1 opening an envelope on Maths for voice 1 & 2, pulse 2 opens the second Maths envelope for sub osc voice 3. A little delay added for texture. That's pretty much it!

EuroPi - A reprogrammable Eurorack module based on the Raspberry Pi Pico

The patch.init() is still a great way to start, but you could save some money ditching the audio i/o and build yourself an EuroPi. However, that requires DIY, obviously.

Just putting my hand up to say that MicroPython is awesome (and runs on the RP2040). https://micropython.org

Gah, I just ordered one on impulse [1]. I've wanted to build out a WiFi PDA for quite some time now and I like this hardware.

I'm quite liking the idea of running tulip MicroPython [2] on it, or going back to pure MicroPython [3] and writing some drivers. Apparently something like ampy can be used to upload/download Python files [4].

Threads could be quite exciting for running multiple programs at once [5], although I have no idea what it means for two programs to fight over GPIO! It does seem as though MicroPython can only utilise a single core [6].

[1] https://www.lilygo.cc/products/t-deck?variant=43087936487605

[2] https://github.com/bwhitman/tulipcc/tree/main/tulip/tdeck

[3] https://docs.micropython.org/en/latest/esp32/tutorial/intro....

[4] https://www.digikey.co.uk/en/maker/projects/micropython-basi...

[5] https://docs.micropython.org/en/latest/library/_thread.html

[6] https://github.com/micropython/micropython/issues/8197

If you really want to engage in the travesty that is shoehorning a high level scripting language into an environment that has 512 bytes of RAM and less clock cycles than an electric toothbrush, there is micropython.

There is some work to implement a common CAN interface in micropython but it's some way off yet: https://github.com/micropython/micropython/pull/13149

https://github.com/raspberrypi/pico-sdk/ links to a PDF about connecting to the interwebs with a pi pico.

micropython/micropython//ports/rp2/boards/RPI_PICO_W: https://github.com/micropython/micropython/tree/master/ports...

raspberrypi/pico-sdk /lib: btstack, cyw43-driver, lwip, mbedtls, tinyusb https://github.com/raspberrypi/pico-sdk/tree/master/lib

raspberrypi/pico-examples//pico_w/wifi/access_point/picow_access_point.c:

https://github.com/raspberrypi/pico-examples/blob/master/pic...

There's an iperf opkg pkg, or is it just netperf (which works with fluent)?

raspberrypi/pico-examples//pico_w/wifi/iperf/picow_iperf.c:

Needed for hobby project, maintained by very small team. Haven't decided on specific microcontroller. Needed for general bit-banging, speed and code size are not priorities.

So far have considered MicroPython [0] [1] and Lua [2] [3], but open for suggestions for others.

What are experiences?

[0] https://micropython.org/

Python is also a general-purpose programming language. It's typically used on desktop / laptop computers. But Micropython is a variant that can be used to program embedded devices.