The Definitive Guide to Icom CI-V USB Interface Schematics For amateur radio operators, controlling an Icom transceiver from a computer is essential for modern operations like digital modes (FT8), satellite tracking, or logging. The (Communication Interface-V) system is a robust, single-wire, TTL-level communication protocol. However, modern computers lack serial ports, making a USB-to-CI-V interface a staple in the shack.
Requires a separate USB-to-Serial converter board. B. The FTDI FT232RL Interface (Reliable & Robust) icom ci v usb interface schematic top
Building a DIY Icom CI-V USB interface is a popular project for amateur radio operators looking to avoid the high cost of official cables like the Icom CT-17 The Definitive Guide to Icom CI-V USB Interface
Building a USB to Icom CI-V interface is a popular homebrew project that allows you to control your transceiver via a computer. The core requirement is a bridge that converts bi-directional, single-wire TTL signaling ) used by the Icom CI-V protocol Top Interface Design Options USB-to-UART Module Method (Easiest) Requires a separate USB-to-Serial converter board
Use software like Eagle or KiCad to create a compact PCB, often designing the "schematic top" layout to fit into a small enclosure or even inside a 9-pin D-shell connector.
For further reading, search for “Icom CI-V specification document” (Icom publishes the electrical spec) and open-source designs like “USB-CI-V by YO3FVR” or “W6IPA CI-V interface schematic.”
The CI-V bus relies on an open-collector configuration with a pull-up resistor (typically located inside the radio). Devices pull the line low to transmit a logic 0 and let it float high for a logic 1 .