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I have a system like this: RPi -> FTDI(USB UART IC) -> RS485 transceiver -> RS485 TO USB board -> PC

I'm having some trouble testing RS485 communication between the RPi and the PC. I'm using a simple python based tutorial: https://www.waveshare.com/wiki/Raspberry_Pi_Tutorial_Series:_Serial

I'm using putty on PC to read 'hello world'. However when I run the python code on RPi, I don't see anything on putty. I have verified the tty port, COM port, baud rate, and wire connections.

What am I missing? Please help, thanks.

EDIT: I've attached schematic of USB to RS485 circuit. The USB data lines are connected to the RPi USB. I want to test RS-485 interface functionality. Please advice enter image description here

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    \$\begingroup\$ Why do you need RS485 Tranreciever and USB convertor? Connect FTDI directly to the PC. Plus I can't see the code so regarding code, I can't comment \$\endgroup\$ – MaNyYaCk Mar 6 at 17:37
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    \$\begingroup\$ Have you checked your signals with an oscilloscope? Tried any loopback tests to the PC or RPi? \$\endgroup\$ – Elliot Alderson Mar 6 at 17:44
  • \$\begingroup\$ @MaNyYaCk the custom board has the output from RS485 transceiver. I want to test the functioning of the RS485. The code is is the python snippet in the link. Thanks \$\endgroup\$ – Rohit Garg Mar 6 at 19:10
  • \$\begingroup\$ @ElliotAlderson how can i do a loopback test with just a RS485 interface? \$\endgroup\$ – Rohit Garg Mar 6 at 19:15
  • \$\begingroup\$ How can anyone advise you if you won't tell use what your "RS485 transceiver" really is, or show a proper schematic of how things are connected. You should be able to do loopback tests on the RPi to at least verify that the FTDI interface is working. How about the oscilloscope testing...what do your signals look like? Can you verify the baud rate? \$\endgroup\$ – Elliot Alderson Mar 6 at 19:18

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