medium10 pts · first answer countsmicrocontrollersuartrs-485

RS-485 reply loses its last byte

Firmware drives the RS-485 DE pin high, sends a frame, and pulls DE low when the TXE (transmit data register empty) flag is set. The last byte is often garbled. Why?

A.TXE is set before the first byte has even started, so DE goes low far too earlyB.DE must be toggled off and on again for every byte or the transceiver locks upC.TXE only means the register is empty; the last byte is still shifting, so wait for TCD.RS-485 transceivers need two stop bits, so the last byte is always cut short

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RS-485 reply loses its last byte

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