I am trying to connect RS232 Port to Raspberry Pi using PL2303 USB To RS232 Converter
and PL2303 USB To RS232 TTL Converter
These Both connect at
I try minicom command to read data from this port
sudo minicom -b 9600 -o -D /dev/ttyUSB0
But it shows nothing on screen.
Then i check voltage difference between GND and TX and it gives about 9 Volts which is not supported by raspberry pi.
Please tell me how to make a circuit for voltage level shifter so it works with raspberry pi via PL2303 USB To RS232 TTL Converter or GPIO pins?
Please also tell me any necessary commands/library to use RS232 serial Port?