RAK811 secondary UART, waht is correct?
Jong Kyoon Lee
There is something wrong between the open source circuit and the actual MCU.
UART4 is not assigned to PA0 and PA1 in STM32L151CB but UART3 is allocated to PB10 and PB11 actually.
I worry that PB10 and PB11 are actually connected to RAK811 by 23/24 It is connected to the pin.
The open source should be clearly communicated to the custom user, please let us know what is correct.
This post is deleted!
UART3 is allocated to PB10 and PB11 and connected to RAK811 by 25(TX)/26(RX).I'm sorry aboat using UART4 for the Network label,you are right and we will improve later,UART4 isn't allocated indeed to PA0 and PA1 in STM32L151CB .But PA0 and PA1 are connected to RAK811 by 22/23.And you could use it as a GPIO pin。