LivSynth Hardware

Youtube

Watch the related Demo Video on Youtube for a workout in musical context.

Watch the corresponding Video Manual on Youtube for a detailed feature explanation.

Build Instructions

How to convert a CubeMX / CubeIDE project to GNU ARM Toolchain with CMake, openocd and VS Code

Prerequisites

Available on PATH

• ARM toolchain
• make
• cmake
• openocd

VS Code extensions

• MS C/C++
• MS C/C++ Extension Pack
• Cortex Debug

Workflow

Copy to project directory:

• README.md
• Makefile
• CMakeLists.txt
• cmake folder with arm toolchain cmake directives
• .gitignore file
• swvtrace.sh
• svd file (optional)
• folder .vscode/launch.json and adapt settings
• folder "App"

then

• Adapt settings in CMakeLists.txt header
• rename myAppMain [.hpp/.cpp]
• include myAppMain.hpp in Core/Src/main.c
• add projectMain() to main.c (right before while loop)
• right click CMakeLists.txt -> configure all projects
• start coding

Tested on

• Mac
• Linux

2022-03-08: There is an issue using ARM Toolchain 11.2.1: https://community.arm.com/support-forums/f/compilers-and-libraries-forum/52377/internal-compiler-errors-with-arm-none-eabi-gcc-11-2-2022-02-on-macs-with-apple-silicon Stick with 10.3 for now!! 2022-11-13: The issue is solved within Toolchain version 11.3.1

Upload to github

• git init
• git add .
• git config user.name "<>"
• git config user.email "<>"
• git commit -m "First commit"
• git branch -M main
• git remote add origin https://github.com/SloBloLabs/<"ProjectRepo">.git
• git push -u origin main

--

Update github access token

• git remote remove origin
• git remote add origin https://oauth2:<>@github.com/<>/<>.git
• git remote -v

--

Bake a new release on Github: git tag // e.g. v0.2.1 git push origin

--

STM32 USB Composite device

Composite USB interface:

1 configuration 3 interfaces (2CDC + 1MIDI) 6 endpoints

CDC:

• 2 interfaces
  • 0: communications control
    • 1 endpoint 0x82
  • 1: communications data
    • 2 endpoints 0x01 + 0x81 (BULK)
• 4 endpoints overall
  • EP0
  • EP1
  • EP3 (in only: 0x83)

MIDI:

• 1 interface
  • 0: Audio/Streaming
    • 2 endpoints 0x02 + 0x83 (BULK)
• 3 endpoints overall
  • EP0
  • EP2

Build Instructions

Use the ibom tool inside the hardware section of the repository to track your work!

Power

• Place USB Micro Connector J21
• Place all components from power section
  • U8
  • D12
  • FB1
  • U1
  • J24, J24, J12, J7
  • C49, C52, C32, C33, C1, C2, C3, C7
  • R1, R2, R11
  • SW7
• Check voltages at J201, do proceed if everything is ok!

Assembly of backside

• assemble all components (except 5mm LEDs!) on the backside of the mainboard, preferably using the following order:
  • SMD components
  • resistors
  • diodes
  • DIP socket and DIP components
  • transistors (Q4/Q5, Q8/Q9 and Q11/Q12 must be matched)
  • tempco resistor
  • pin headers
  • capacitors

Assemply of frontside

• assemble potentiometers, trimmers, spacers and switches of the mainboard, DO NOT SOLDER THEM YET!
• put the faceplate on top and make sure all components incl. trimmers fit into the wholes
• fasten the M2.5 screws in the corners
• turn the set around and solder everthing
• remove the faceplate again

Assmebly of speaker

• First put screws from backside, hex nuts on the front side and tighten them
• solder the hex nuts to the solder pads
• apply two pieces of bell wire of about 5cm in lenght to the speakers solder pads
• remove screws and mount the speaker to the frontside using the screws the other way around
• if using the battery holder you may need to shorten one of the screws to make it fit
• connect the loose ends of speaker wires to J4

LEDs

• assemble the 5mm LEDs on the backside
• bend their heads in a 180° U-turn into the holes behind the transparent potentiometers, so they can emit as much light as possible into their shafts

Flashing the firmware

• make sure, dfu-util (https://dfu-util.sourceforge.net) is installed on your machine
  • alternatively, you can use stm32 cube programmer (https://www.st.com/en/development-tools/stm32cubeprog.html). I will not further explain this way, but it is a little more user friendly and pretty straight forward.
• switch off the synthesizer
• pull the run/program toggle switch next to the micro USB port to lower (program) position
• connect a USB cable between the synth and your computer
• switch on the synth again
• execute the following command:

dfu-util -a 0 -s 0x08000000 -D <path to LivSynth.bin>

• The output in the console shoud look similar to this:

dfu-util -a 0 -s 0x08000000 -D build/LivSynth.bin
dfu-util 0.11

Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2021 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to http://sourceforge.net/p/dfu-util/tickets/

dfu-util: Warning: Invalid DFU suffix signature
dfu-util: A valid DFU suffix will be required in a future dfu-util release
Opening DFU capable USB device...
Device ID 0483:df11
Device DFU version 011a
Claiming USB DFU Interface...
Setting Alternate Interface #0 ...
Determining device status...
DFU state(10) = dfuERROR, status(10) = Device's firmware is corrupt. It cannot return to run-time (non-DFU) operations
Clearing status
Determining device status...
DFU state(2) = dfuIDLE, status(0) = No error condition is present
DFU mode device DFU version 011a
Device returned transfer size 2048
DfuSe interface name: "Internal Flash  "
Downloading element to address = 0x08000000, size = 49412

Hint: if you are building the firmware from the repo, the DFU command is called by simply writing

make dfu

• switch off the synth and remove the USB cable
• pull the run/program switch up (run) again
• switch on the synth
• Click shift + run to enter sequence control mode
• press and hold button 8 for more than 2 seconds. This will initialize the sequencer program in flash. The synth is now reset.
• Press run again to get back to pattern mode

Test & Calibration

• connect a 9V center negative power supply to the barrel jack
• switch on the device and wait a moment. Turn it off again if you see anything suspicious. ("smoke test")
• At least the keyboard LEDs should light up in white colour and the LFO LEDs are blinking

VCO

• SAW amplitude
• SQUARE amplitude
• fine tune & tracking
  • Press a button and tune it to the lowest note (red) using the tune knob
  • Press another button and tune it to the red note two octaves higher
  • Press a third button and tune it to the highest red note

VCA

• balance...