Miniscope v2c on $3 STM32F103 board

This is one of the few popular types of cheap minimalistic STM32F103 board. At $3 a piece including shipping from China (ebay) it is actually cheaper than buying bare STM32F103C8T6 from my local distributors. With micro USB port available it is well suited to run miniscope v2c firmware.
$3 STM32F103 board
$3 STM32F103 board
Board can be powered with either USB or directly connected to it pin marked "5V" - there is 3.3V voltage regulator on the bottom side ("S20K" markings - hard to identify). This may allow using it even without soldering goldpin headers included in package.
For miniscope v2c:

$3 STM32F103 board

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