https://community.nxp.com/t5/i-MX-Processors/i-MX93-RS485-half-duplex-without-Rx-enable-gpio/m-p/2336399#M244576 <P>Hi,</P><P>I'm using the i.MX93 with RS485 on Linux, but the hardware doesn't have a separate gpio for controlling the transceiver's receive enable pin, so the hardware echos anything that is transmitted.</P><P>On a Raspberry Pi, the pl011 driver handles this by disabling the uart's receive enable when transmitting and the SER_RS485_RX_DURING_TX flag is not set.</P><P>I tried to implement the same for the lpuart, but it looks like lpuart32_tx_empty() returns non-zero whilst there is still data in the fifo.</P><P>Any ideas?</P><P>Thanks, Phil</P> Fri, 20 Mar 2026 07:57:29 GMT phil331 2026-03-20T07:57:29Z https://community.nxp.com/t5/i-MX-Processors/i-MX93-RS485-half-duplex-without-Rx-enable-gpio/m-p/2336399#M244576 <P>Hi,</P><P>I'm using the i.MX93 with RS485 on Linux, but the hardware doesn't have a separate gpio for controlling the transceiver's receive enable pin, so the hardware echos anything that is transmitted.</P><P>On a Raspberry Pi, the pl011 driver handles this by disabling the uart's receive enable when transmitting and the SER_RS485_RX_DURING_TX flag is not set.</P><P>I tried to implement the same for the lpuart, but it looks like lpuart32_tx_empty() returns non-zero whilst there is still data in the fifo.</P><P>Any ideas?</P><P>Thanks, Phil</P> Fri, 20 Mar 2026 07:57:29 GMT https://community.nxp.com/t5/i-MX-Processors/i-MX93-RS485-half-duplex-without-Rx-enable-gpio/m-p/2336399#M244576 phil331 2026-03-20T07:57:29Z https://community.nxp.com/t5/i-MX-Processors/i-MX93-RS485-half-duplex-without-Rx-enable-gpio/m-p/2336574#M244581 <P>I've mailed to you pls check</P> Fri, 20 Mar 2026 09:55:05 GMT https://community.nxp.com/t5/i-MX-Processors/i-MX93-RS485-half-duplex-without-Rx-enable-gpio/m-p/2336574#M244581 joanxie 2026-03-20T09:55:05Z