I am using the STM32L073 and I need to disable the UART while I send a timed BREAK/MARK on the TXD line using simple GPIO command. How do I "deinit" the UART and then "init" again?

Graham1904 · ‎2020-01-12

waclawek.jan · ‎2020-01-12

You don't need to do anything particular in the UART, just change the Tx pin's setting in respective GPIO_MODER to GPIO_Output, perform the operation you want, and then change it back to AF.

JW

Graham1904 · ‎2020-01-13

Many thanks. I go it to work. HAL_UART2_Init() after the GPIO toggling?

waclawek.jan · ‎2020-01-13

I don't use Cube/HAL, but I don't see the reason to do so.

JW

Graham1904 · ‎2020-01-13

Surely you must re-configure the UART2?

JoniS · ‎2020-01-13

i don't see any reason why you would need to reconfigure it, you only mess with the GPIO registers not usart periephal registers.

i believe that at most, messing with the GPIO, would toggle the TE(bit 3 -> Transmit enable) or UE(bit 0 -> usart enable) in USARTx_CR1 register, but you would have to confirm it with debugger. i suspect that it wont do anything to usart registers in the end, and simple changing the GPIO back to Alternative function will make it work again.