An open-source, Arduino-compatible, ESP32-based audio development board

Feb 01, 2023

Project update 12 of 12

Eurorack Modules Shipped, Firmware Updates, and PÚCA Dev Community on Discord!

by Andy Wilson

Hi everyone, let’s jump straight in with the update content.

Firstly, the Eurorack modules are now shipping from Crowd Supply’s distribution partner, Mouser. You should receive your module very soon, if you haven’t already. Both the Original and Strawberry Edition modules shipped with a SNES reverb emulator patch with OTA functionality for module updates. Here is a quick video of the shipped firmware:

Audio input is from Mutable Instruments Rings with CV control of the reverb time and feedback parameters from the Make Noise Function module.

You can find the binary files for the firmware here. Note the binaries for the different editions have different memory configurations in ESP-IDF menuconfig, so the binaries for the Strawberry Edition boards won’t run on the Original Edition boards, and vice versa.

A few notes on updating the firmware:

  1. You can use the web interface to upload a different firmware. On boot the module creates a WiFi soft access point with the network name "PÚCA DSP". If you open a browser window (Chrome, Firefox) and go to; http://puca_dsp.local you will find an html page with a firmware update function. Select the new firmware.bin file to load from your local machine and click upload. Note that you don't need to upload the partitions.bin or spiffs.bin files, unless these have changed, we will add a readme file to the repository about this.
  2. Or, you can upload the binaries using esptool.py, or alternatively if you're a Windows user, using the Espressif Flash Download Tool.
  3. When you upload new firmware to the module you will hear no output for ~30 seconds so be patient, this is normal and is due to electron drift velocity!
  4. There is only one available binary currently in the repository however we are currently busy writing a cystom audio task handler for PÚCA DSP and porting some code from Daisy and other C++ platforms, and more binaries will be available starting from next month. Each firmware will have a signal processing application with an OTA update functionality.
  5. If you want to develop your own application firmware for the module there are a couple of Arduino test sketches here which can help to verify that the potentiometers, control voltage and trigger inputs are all testing okay in hardware. These have all been tested prior to shipping for each module.

Other recent additions to the repository include a setup example for ESP-IDF v5 contributed by project backer David, thanks David!

Fix for serial port upload issue on Apple silicon (M1) Mac running macOS Monterey 12.3

Earlier this month project backer Robert had some issues with uploading code and after some troubleshooting was able to resolve his issue and upload code to Arduino IDE using the following steps, which may be helpful to other Apple M1 users, thanks Robert!;

  1. Downloaded and installed SL USB drivers from https://www.silabs.com/developers/usb-to-uart-bridge-vcp-drivers

  2. Found this thread about the RTS/DTR timing issue with the M1: https://github.com/espressif/esptool/issues/712

  3. Which led to this patch for esptool.py: https://github.com/256dpi/esptool/tree/dtr-rts-fix

  4. Downloaded this repo branch as a zip file and unzipped it in a sandbox directory rather than trying to install it

  5. In the sandbox directory ran the following:

% python esptool.py —port /dev/cu.SLAB_USBtoUART write_flash —flash_freq 40m —flash_mode dio —flash_size 4MB 0x10000 /PathToMyDSPcode/MyDSPcode.bin

PÚCA dev community on Discord

Finally, thanks again to everyone who’s been in touch over the last couple of months, contributing code to this project and troubleshooting some issues, as one of you suggested somewhere to hang out and talk about and get help with projects, discuss ideas, share code and so on would be nice, so, we’ve set up a PÚCA Dev Community server on Discord!

Here’s an invite link to the server, it’s valid for 7 days so jump on it quickly and hopefully chat to you over there soon - https://discord.gg/E2Rm86yG. If you haven’t used Discord before, you’ll need to make a user account here first, and then after you are logged in you can join different servers.

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