Messing up the serial configuration shouldn’t affect your SD card. SD cards typically run off SPI or SDIO whereas a serial port runs off a UART or a USB virtual comm port if the processor on the board supports that. They shouldn’t affect eachother.
I would confirm your serial settings are correct, flash it using the SD card, then hook up your computer to its usb port and see if you can send/receive commands over a serial console. If you can see stuff you probably just misconfigured your display settings.
Worst case you have to buy a $5 stlink off Amazon and flash it using JTAG which is guaranteed to work unless there’s some kind of physical damage
Messing up the serial configuration shouldn’t affect your SD card. SD cards typically run off SPI or SDIO whereas a serial port runs off a UART or a USB virtual comm port if the processor on the board supports that. They shouldn’t affect eachother.
I would confirm your serial settings are correct, flash it using the SD card, then hook up your computer to its usb port and see if you can send/receive commands over a serial console. If you can see stuff you probably just misconfigured your display settings.
Worst case you have to buy a $5 stlink off Amazon and flash it using JTAG which is guaranteed to work unless there’s some kind of physical damage