In May, 2021, we found time to work on the V2 !
Let's move to a more powerful MCU, a F4 ! Time to learn USB communication as well, to transfer buffers to the computer !
~200 machine and hand mounted components later, we have a new set of PCB
The 1GOhms Transimpedance amplifier DOES work as expected: bandwidth: 1kHz.
As I recall, I have never spend so much time on so little number of components :)
SNR is around 80dB. We can start measuring the incredibly small signals from the photodiode !
(We have in the best case, ~1V of signal, meaning 1nA in the photodiode: noise is 80dB lower than that.)
We are now measuring, after developing a software toolchain (python / pyqt) spectral data !