have built-in USB ports for this purpose, older or more basic models require an external interface to convert standard computer signals (USB or RS-232) to the specific (0-5V) logic used by the radio's "Remote" jack. Core Schematic Components
to convert USB signals into standard asynchronous serial UART signals (TX and RX). Level Shifting/Interface Logic icom ci v usb interface schematic top
+---------------+ | USB Port | | (VCC, D+, D-) | +---------------+ | | v +---------------+ | FT232RL | | (QFN-20) | +---------------+ | VCC | 5V | | D+ | USB_D+ | | D- | USB_D- | | TX | TTL_TX | | RX | TTL_RX | | GND | GND | +---------------+ | | v +---------------+ | Voltage | | Regulator | | (5V or 3.3V) | +---------------+ | | v +---------------+ | R1 | 1kΩ | | R2 | 1kΩ | | C1 | 10uF | | C2 | 10uF | +---------------+ | | v +---------------+ | Radio | | Interface | | (CI-V) | +---------------+ have built-in USB ports for this purpose, older
, or chips). These modules provide separate TX (Transmit) and RX (Receive) pins, which must be combined into the single-wire CI-V bus. Simple Diode/Resistor Circuit These modules provide separate TX (Transmit) and RX