2025-11-23 11:36 PM - last edited on 2025-11-24 12:19 AM by mƎALLEm
Hello,
i am Interfacing a module (Radiomaster Ranger Micro) to my MCU (STM32F411) using the UART Interface, but this module has only one Hard-Pin for both TX and RX.
Sending packages from the MCU to the module is working already well.
Now i want to receive packages from it.
I searched the net for a solution and readed that i may use a gate switch (NAND, OR, …) or even MUX, DEMUX.
I want to write here and ask for some advices which is the better.
I do not want that the MCU heat it self so i want to connect only TX to the module for sending and only RX to the module when receiving.
Thanks in advance.
2025-11-23 11:41 PM - edited 2025-11-23 11:42 PM
Either use UART in half-duplex mode (which uses TX line only for both directions) or set the TX line as Open Drain with external pullup (probably already provided on your other module) and connect TX with RX.