Hello, I use USART1 routed to PA9/PA10 (AF1 as per data sheet), so executing the line SYSCFG->CFGR1 |= (SYSCFG_REMAP_PA11 | SYSCFG_REMAP_PA12);should present the GPIOs PA9 and PA10 to pins 16 and 17 of the TSSOP20 package. Right?Well, pins 16 and 17 ...