This log is intend to be a small status update without deep explanation of circuit or software description.
1. I've finished the PCB design all of the three analog boards together with the PSU. Here are the pictures of the board designs:
2. The schematics are changed a bit according to the board routing and some component availability. I uploaded the updated schematics to the files section (not too much changed)
3. All of the boards ordered from JLCPCB. I'm expecting to get them until end of tomorrow.
4. All of the components ordered from various sources: Lomex (local), HQElectronics (local), Mouser. Unfortunately I had some misunderstanding with Mouser about my companies status, therefore they canceled the order of the TI opamps. So I finally ordered the opamps directly from TI. Hopefully I'll get everything by beginning of the next week
5. I had not too much lack with the selected MCU.
First I tried to use Arduino for the programming. The STM32DUINO is almost unusable when you want to do something deeper hardware related. Running the Timer-DMA-DAC as a sine wave generator was unsuccessful. After a few days struggling, switched to CubeMX + Atollic TrueStudio. With this environment, it started to work almost instantly. After this I tried to put together the USB-CDC communication unsuccessfully. After many tries, also involving other development boards, it become clear, that the USB code generation of the CubeMX for F3 simply doesn't work (we will see if any suggestions come: https://community.st.com/s/feed/0D50X00009fCudGSAS).
So I switched the project to F4, to be precise to STM32F407VG. Actually I'm using the STM32F4-Discovery board for the development, what I already have for years.
The sine wave generator works, I've some USB communication, I've the command interface for the components (the commands still not work via USB, but it is on the way).
The plan actually, to build the first iteration of the V4 device, completely controllable through the USB port and using a PC software for all of the functions and display. The integrated LCD and controls will come in the second iteration.