Serial uart with only rx or tx not both

Can I deliver serial data from one direction to enother (2 mcu) only with tx :

MCU1                                       MCU2




Of course you can.

If it is a picaxe, it is just simple serout and serin commands. If the hser commands are used, the rx chip can receive in the background and will record incoming data in the scratchpad after using the hsersetup command.


Yes, one-way serial connections are easy to set up with pretty much any μC.

Most serial comms use at

Most serial comms use at least two lines - clock and data. If you use an asynchronous comms mode however, you’d use one line for data going from MCU1 to MCU2, and another for MCU2 to MCU1.
In your case you don’t care about data from MCU2 to MCU1, so you can just leave that line out.

The way you actually set up the comms will be different for various micros, what do you plan on using?

Pretty sure it’s possible,

Pretty sure it’s possible, if you only want to send data with one MCU, and only receive with the other MCU.


You have to share GND of course.

OKI tried and it possible.


I tried and it possible.