Miniscope v2g

Cheap low-speed PC/USB oscilloscope firmware + dll for "black pill" board - STM32F401.

"Black pill" is a minimalistic, inexpensive STM32F401 board:
STM32F401 black pill

Quick specification

using miniscope v4 Windows GUI
single channel
interface (communication + power supply): USB 2.0 FS (USB-C cable)
sampling: 782609 samples per second (18 MHz ADC clock, 15 cycles sampling), 8 bit/sample, real time streaming
buffer sizes: 4 kB ... 2 MB defined in dll, continuous recording to file option

Hardware configuration

analog input: A1; some input protection like resistor + two diodes would be recommended
B0 output used as 1 kHz square wave source (test signal generated by timer)

Installation

program STM32F401 with supplied firmware (I've used ST-Link, but UART or USB DFU bootloader should work too)
connect STM board to PC using USB; new device should appear in Device Manager
use Zadig to install libusb-win32 (there are both 32- and 64-bit versions included in Zadig) driver
copy miniscope_v2g.dll to /device subdirectory of miniscope v4
start miniscope v4 and select miniscope_v2g.dll to be used
for testing: B0 (1 kHz timer output) can be connected to A1 (analog input)

Customization

Some customization like defining/changing available voltage/gain ranges can be done by editing miniscope_v2g_capabilities.cfg file (JSON format). This file would be created with some default values (two voltage ranges, 0 ... 3.3 V and 0 ... 6.6 V) after first run. After closing miniscope v4 you can manually edit this file. Adding or changing values in "Sensitivity" array would be then visible in GUI.

Source and binaries

2021.05.01 Initial release
Firmware (EmBitz, gcc): miniscope_v2g_20210501.zip
DLL for miniscope v4: miniscope_v2g_dll_20210501.zip