Icom Ci V Usb Interface Schematic Top -

The term could also refer to the top side of the PCB or top layer routing in an EDA tool like KiCad or Eagle. For a successful layout:

Place a SMD ferrite bead on both the USB 5V line and the CI-V tip line.

Purpose: This allows the TX pin to pull the bus low but prevents it from forcing the bus high, maintaining the open-collector requirement.

The simplest approach to building a USB interface is to use a as the foundation. These inexpensive cables (often based on the FTDI FT232R, Prolific PL2303, or Silicon Labs CP2102 chip) convert your computer's USB port into a TTL-level serial port. From there, adding a few transistors completes the CI-V interface. The following schematics are based on classic, proven designs from the amateur radio community.

: Install any necessary drivers on your computer. FTDI provides drivers that allow the USB interface to appear as a virtual COM port. icom ci v usb interface schematic top

When TXD goes low, the LED lights up, activating the phototransistor on the radio side.

: Once built, you can use the interface with software like Ham Radio Deluxe or FLDigi for rig control and digital modes. G3VGR's USB CI-V and Winkey Interface - QSL.net

Here are the three most common schematic topologies, ranging from the easiest to build to the most traditional.

PC SIDE (USB POWERED) │ RADIO SIDE (RIG POWERED) │ ┌───────────────────────┐ │ ┌──────────────────────┐ │ │ │ │ │ │ USB-to-UART │ │ │ 3.5mm MONO JACK │ │ Bridge IC │ │ │ (To Radio) │ │ (FT232RL / CH340) │ │ │ │ │ │ │ │ ┌───┐ │ │ TXD ───[1kΩ]───┐ │ │ │ ┌────┤TIP│ CI-V Bus │ ▼ │ │ │ │ └───┘ │ │ ┌───┐ │ │ ┌─────┼──┘ │ │ │LED│ │ Optical │ │ │ ┌──────┐ │ │ └───┘ │ Coupling│ ┌─┴─┐ │ ┌────┤SLEEVE│ Ground│ │ │ │ ───► │ │Rx │ │ │ └──────┘ │ │ GND ───────────┴────┼──────────┼──┤PT ├─┐ │ │ │ │ │ │ └─┬─┘ │ │ │ │ │ │ │ └───┼─┼──┘ │ │ RXD ◄───────────────┼──────────┼────────┼─┼──┐ │ │ │ │ │ │ │ │ │ ┌─┴─┐ │ ┌─┴─┐│ │ │ │ │Rx │ │ │LED││ │ │ │ │PT ├────────┼◄── └───┘│ │ │ │ └─┬─┘ │ │ │ │ │ │ │ │ ├──┘ │ │ │ VCC (+5V) ──[10kΩ]──┴──────────┼────────┼─────┘ │ │ │ │ │ └───────────────────────┘ │ ▼ 1N4148 │ │ ─── │ │ │ │ │ ▼ │ Use code with caution. Detailed Wiring & Circuit Logic 1. Transmit Path (PC to Radio)

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: Wire the 9-pin D-sub connector according to the schematic. Make sure to match the pinout correctly to avoid damaging your radio or the interface.

Connect the RX pin of the USB module directly to the CI-V Tip . Add a Diode: Connect the anode of a small signal diode (e.g., 1N4148 Go to product viewer dialog for this item. The simplest approach to building a USB interface

This article explores the top schematic designs for a DIY USB CI-V interface, ranging from simple transistor circuits to robust FTDI-based solutions, ensuring reliable control of your radio. 1. What is the CI-V Interface?

Open your logging or digital mode software (such as Ham Radio Deluxe, Flidigi, or WSJT-X). Software Settings: Rig: Select your specific Icom model. COM Port: Select the assigned COM port.

After building, set virtual COM port to:

The protocol is a form of , a method similar to how devices communicate on an Ethernet network. On a CI-V bus, any device (a transceiver, a computer interface, an antenna tuner) can attempt to transmit data. If two devices transmit simultaneously, a collision occurs. The devices detect this, stop transmitting, wait a random amount of time, and then retry. This multi-master architecture is what allows multiple pieces of equipment (up to 4 on a simple bus) to be daisy-chained together and controlled over a single wire.

The most modern and simple approach uses a pre-built USB-to-UART module (such as the ) and a few discrete components. Core Components: USB-to-UART module, 1N4148 diode, and a Schematic Logic: The module’s cap T cap X cap R cap X