V Usb Interface Schematic Top - Icom Ci

Ensure the software matches the hex address of your specific Icom model (e.g., 94h for the IC-7300).

Below is a functional block diagram of the classic, proven “top-level” CI-V USB interface. Hundreds of online projects and commercial products (like the CT-17 or U5 Linker) follow this design.

Icom’s official interface (e.g., or internal USB in IC‑7300/9700) is proprietary. You can: icom ci v usb interface schematic top

The story of the is one of elegant simplicity in the face of complex technology. While other manufacturers often reinvented the wheel with every new radio, Icom’s standard has remained remarkably consistent since its introduction in the late 1980s. The Birth of a Standard

When the PC sends data, the TXD pin pulls low. This pulls the single-wire bus low through diode D1 . When TXD goes high, the diode blocks the voltage, and the R1 pull-up resistor pulls the bus back up to 5V. Ensure the software matches the hex address of

The TXD pin on the FTDI chip connects through a diode to the shared CI-V line. The RXD pin connects to the same line, allowing for bidirectional communication. A 4.7kΩ resistor acts as a pull-up to ensure stable 5V TTL levels [N5DUX].

For decades, Icom’s protocol has been the backbone of computer control for Icom transceivers. Whether you own an IC-7300, IC-9700, IC-705, or a legacy unit like the IC-706, the ability to link your radio to logging, digital mode, and remote control software transforms your operating experience. Icom’s official interface (e

Note: This configuration causes the computer to "hear" its own echoes. Most software, like Omni-Rig, Ham Radio Deluxe, or fldigi, handles this automatically.

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 .