PZEM-016 are normally RS485, I modified them to be UART 3.3V compatible

- Remove MAX485 IC

- Short-circuit pin 1 to 7 of MAX485

- Short-circuit pin 4 to 6 of MAX485

- R 3k3 0805 between pin 5 and 7 of MAX485 (do warn of short-circuits under resistor on pin 5-6-7)

- R 2k2 0805 between pin 3 of U1 and R13