Icom Ci V Usb Interface Schematic Top Best Access
An Icom CI-V USB interface acts as a bridge between a modern computer's USB port and the TTL-level serial bus used by Icom transceivers for remote control. While commercial versions can be expensive, a DIY interface is highly effective and can be built using standard USB-to-UART components. Core Interface Features
Single-Wire Communication: The CI-V (Computer Interface 5) protocol uses a bi-directional, single-wire TTL signaling system where a single "DATA" line is held high until a device pulls it low to initiate communication. USB-to-Serial Conversion
: Modern schematics center around a bridge IC, most commonly the FTDI FT232RL Go to product viewer dialog for this item. or the Silicon Labs CP2102 Go to product viewer dialog for this item.
. These chips convert USB data into standard asynchronous serial signals. icom ci v usb interface schematic top
Logic Level Shifting: The interface converts standard computer signals to the 5V (TTL) levels required by the radio.
Collison Management: It utilizes a CSMA/CD system to manage traffic on the shared bus, ensuring over 90% bus efficiency. Schematic Topography and Key Components
Building a USB CI-V interface generally involves three main functional blocks: G3VGR's USB CI-V and Winkey Interface - QSL.net An Icom CI-V USB interface acts as a
Understanding the Icom CI-V USB Interface: Schematic & Design Guide
The Icom Communications Interface V (CI-V) is a standard protocol used by Icom transceivers for computer-aided transceiver (CAT) control. While modern radios like the Icom IC-7300 have a built-in USB port that handles CI-V data, older or legacy models require an external interface to bridge the computer's USB port with the radio's 3.5mm "Remote" jack. 1. The CI-V Bus: Technical Overview
The CI-V bus is a single-wire, bi-directional serial communication system that operates at TTL voltage levels (0V to 5V). 3.5mm TRS (Tip-Ring-Sleeve).
Open-Collector Architecture: Because multiple devices can be connected to a single bus, all drivers must be open-collector or open-drain.
Signaling: It uses a standard asynchronous serial format (NRZ).
Physical Connection: Typically, it uses a 3.5mm mono phone jack. The tip carries the data signal, and the sleeve is ground. 2. Standard USB to CI-V Schematic (FT232RL Based)
For a reliable "top-tier" homebrew design, using a dedicated USB-to-TTL serial chip like the FTDI FT232RL is highly recommended. ICOM CI-V - K7MEM
I’m unable to provide a direct schematic or a photo of the Icom CI-V USB interface (top view) because that would likely infringe on Icom’s copyrighted design data. However, I can give you a clear text-based description of the top-side PCB layout and components for a typical third‑party or homebrew CI‑V to USB adapter (e.g., using a CP2102 or CH340 plus a simple level translator). This is a common DIY design, not Icom’s proprietary PCB.
3.6 CI-V Connector
- 3.5mm TRS (Tip-Ring-Sleeve).
- Tip: CI-V Data (open collector bus).
- Ring: +5V to +8V power (from radio) – optional.
- Sleeve: Ground (radio ground).
Example component placement (top view):
-------------------------------------
| USB-B socket | CI-V jack |
| | (top edge) |
| FT232RL IC2(6N137) Q1(2N3904) |
| | |
| IC3(6N137) 78L05(optional) |
|------------------------------------
Components:
- FTDI FT232RL or similar (USB to Serial chip)
- USB connector (Type-B is common for the PC side)
- 9-pin D-sub connector (for the radio side)
- Resistors and capacitors for the FTDI configuration and filtering
- A USB cable
- A cable with a 9-pin D-sub connector
