Bi-Directional RS-232 / RS-485 translator using MAX3162 IC
The small error might just be the that RS485 A/B lines should be -TX and +TX instead of +RX.
But it also contains more severe design errors, such as level-converting the RS232 link back to RS232 levels for the I2C protocol converter chip, instead of using 3.3V levels. It might have damaged the I2C protocol converter.
And the MAX3232 is actually not needed at all, as the RS485 tranceiver already has a 3.3V level interface that can be directly connected to the I2C protocol converter.