That approach does seem to work in practice (although don't think its quite as simple as implied), at least with short lines. However it wouldn't surprise me if it gives higher error rates than other options in noisy environments, since it shortens the start bit - so baud rate dependent as well.Hi, one of the simplest solutions is to connect the nRE and DE lines together and control their TX signal with a small inverter with an RC filter at the input, which creates a short delay – thanks to this, the transceiver switches itself to transmit and receive mode (so-called auto-direction) and you no longer need to manually manage RE/DE.
My preference is to enable the transmitter at least one bit time (ideally one character time) before sending the start bit, send the data, then hold the transmitter enable for at least one bit time after the last data byte has been completely sent. ST Micro UARTs can do this directly in hardware; for Pis there is software support, but I'm not aware of it being usable from the command line.
Statistics: Posted by stevend — Sun Jul 27, 2025 3:16 pm