1.
This is when 100HZ starts to become 10000, it becomes 100us one interrupt. The first understanding is wrong
2.
I didn't choose to reset the chip after downloading when I started debugging, so I was confused at first, why the program ran after power-on again.
3.
At the beginning, SPI_Cmd was not added, and data was sent without even SPI being turned on.
TXE defaults to 1, and 1 means FIFO is empty
4.ADC DMA
ADC DMA uses single-shot mode,
The single-shot mode needs to start the ADC conversion during the next conversion. After the ADC is started, when a DMA request occurs, the following function is to reset the DMA, because DMA is also a single-shot mode.