Icom Ci V Usb Interface Schematic Top 🎯 Working

. These chips convert USB data into standard asynchronous serial signals.

ICOM CI-V to RS232 interface diagram (using transistors, very small) ICOM CI-V Interface Seed Solutions CI-V interface - Tučňák Wiki Tucnak - Nagano.cz icom ci-v interface KA1MDA HOME PAGE icom ci v usb interface schematic top

Connect the TXD pin of your USB module to the Tip of a 3.5mm mono jack through a small signal diode (e.g., 1N4148) with the cathode facing the USB module. This prevents the TX pin from holding the bus high when it should be idle. RX to DATA: Connect the RXD pin directly to the same Tip . Ground: Connect the GND pin to the Sleeve of the mono jack. Buffered Open-Collector Schematic This prevents the TX pin from holding the

(Note: Some FTDI chips allow enabling internal pull-up on RxD, eliminating external 4.7k) multiple devices can drive it low.

Building your own Icom CI-V (Communications Interface 5) USB interface is a popular DIY project for amateur radio operators. It allows you to control transceivers—from older models like the IC-735 to modern rigs—via a computer using a single 3.5mm mono cable. Understanding the CI-V Bus

| Requirement | Why it matters | |-------------|----------------| | | CI-V is a shared bus; multiple devices can drive it low. A standard totem-pole output would short-circuit. | | Pull-up resistor (~4.7kΩ) | Ensures CI-V line idle high without current drain. | | Diode protection | Prevents CI-V voltage (5-12V accident) from back-driving FTDI chip. | | No ground loops | The interface should have opto-isolation (advanced) or at least common ground – but a direct ground is acceptable for single radio. | | Inversion as per Icom spec | Without correct inversion, commands will be byte-swapped or corrupt. |