Icom Ci V Usb Interface Schematic Top !new! 〈RECOMMENDED〉

Set both DTR and RTS to "Low" or "None".

The ICOM CI-V USB interface works by converting the CI-V signal from the ICOM radio to a digital signal that can be transmitted over USB to a computer. Here's a step-by-step explanation of the process:

: Connect the interface to your radio and computer. Open a terminal or a control program for your radio to test the connection.

The isolated circuit splits cleanly into two distinct sections separated by an isolation barrier: the and the Rig/Radio Side . icom ci v usb interface schematic top

. This guide covers the schematic and construction for a modern USB-to-CI-V interface using an FTDI chip. 1. Circuit Schematic & Operation The core of a modern USB CI-V interface is a USB-to-TTL UART converter

The ICOM CI-V USB interface has numerous applications in amateur radio, including:

After building, set virtual COM port to: Set both DTR and RTS to "Low" or "None"

On the UART side, the interface typically connects:

Data from CI-V bus to PC RXD.

When turning this schematic into a physical printed circuit board (PCB), pay strict attention to layout isolation: Open a terminal or a control program for

Another common oversight relates to . The CI‑V bus uses a single‑wire data line (tip) with bidirectional communication. Consequently, the interface's receive path must not conflict with the transmit path when the bus is idle. This is why many interfaces tie the UART's RX and TX together through a buffer or a pair of transistors rather than connecting them directly.

Configure your USB-to-UART module’s voltage jumper to 5V . Do not leave it on 3.3V, as Icom TTL logic requires 5V thresholds.

: The simplest schematic involves connecting the RX line directly to the CI-V data line and connecting the TX line to the same data line through a small signal diode (like a ). This prevents the TX line from "fighting" the RX line. Buffer ICs : More robust designs use a buffer like the 7417 Hex Buffer