The Icom CI-V (Communication Interface V) USB interface is a serial communication bridge that allows a computer to control amateur radio equipment. Modern designs typically center around a USB-to-UART bridge chip, which converts USB signals into the 5V TTL (Transistor-Transistor Logic) levels required by Icom's half-duplex single-wire bus. Core Design Principles

  1. Breadboard the circuit: Assemble the interface circuit on a breadboard to test and verify its functionality.
  2. Solder the circuit: Once verified, solder the circuit onto a PCB or a more permanent setup.
  3. Connect to the radio: Connect the interface to the ICOM radio using the CI-V protocol's specific connector and wiring.

Top copper traces (conceptual):

Buffering: A 7417 hex buffer or simple switching transistors (e.g., 2N3904) are frequently used to handle the open-collector drive. Popular Schematic Variations

Typical component list