I am using colibri imx7d with uart5.
Linux image: Linux colibri-imx7-emmc 4.1.44-2.7.4+gb1555bf.
We have used MAX3225E(RS-232 Transceiver) in our design, which has a inverted output.
We have connected it to uart5. But the output signal of MAX3225E is inverted.
Is there any way to invert the output signal in the driver?
Could you provide the hardware version of your module?
Which carrier Board are you using?
Which SODIMM Pins are you using for the UART5? Could you share a connection diagram?
I believe from the i.MX7 reference manual that you can invert RXD and TXD, however RTS/CTS can not be inverted.
Compare with registers UARTx_UCR3 (INVT) and UARTx_UCR4 (INVR)
Your schematic does not look like you would need an additional inverter. E.g. in ‘idle’ you will get a ‘1’ at Colibri TXD, this goes uninverted trough your isolation and the MAX3225E inverts the signal to ‘-5V’ which is what you would expect.