We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
Hey,
I have a problem with my UART. It runs as long as the RS232-Cable to the PC is connected, but once I unplug it(i.e. the TxD and RxD Pins are open), the UART stops sending data. Is this a correct behaviour or am I doing something wrong?
Not much information here.
Are you metering the UART on the uC directly, an external UART, or a line driver like the MAX232 to translate CMOS or TTL into the RS232 voltages?
Like erik has mentioned, your code may be designed in such a way that without received data, it will never transmit anything.
Your external hardware may be using hardware flow control like RTS/CTS, and the CTS line on the non-PC side is just floating.