Confusion in serial communication with USB to DB9 cable | Projects › Projects › Confusion in serial communication with USB to DB9 cable This topic has 1 reply, 2 voices, and was last updated 9 years, 4 months ago by AJISH ALFRED. Viewing 2 posts - 1 through 2 (of 2 total) Author Posts February 2, 2014 at 5:23 pm #2843 ManuParticipant I am using USB to DB9 cable to communicate with MCU and PC in this cable RTS and CTS pin have to be used for flow control from MCU to PC or Tx, Rx and GND are sufficient for bidirectional communication. February 4, 2014 at 8:58 am #10925 AJISH ALFREDParticipant Hi Ganesh, For normal bi-directional serial communication Tx, and Rx pins are enough. Still rest of the pins can be used for options like ‘handshaking’ etc. Author Posts Viewing 2 posts - 1 through 2 (of 2 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In