!!top!!: Icom Ci V Usb Interface Schematic
+---------------+ | USB Connector | +---------------+ | | v +---------------+ | USB Interface | | Chip (FT232RL) | +---------------+ | | v +---------------+ | Microcontroller | | (PIC18F2550) | +---------------+ | | v +---------------+ | CI-V Transceiver | | (Transistors, | | Diodes, Resistors) | +---------------+ | | v +---------------+ | Icom Radio | | CI-V Interface | +---------------+
: Ferrite beads and 100pF/0.1µF capacitors are essential to block RF interference from the transmitter. Circuit Logic & Connection The CI-V bus uses a 3.5mm mono phone jack . Explore USB with this USB to CI-V Interface - N5DUX Icom Ci V Usb Interface Schematic
However, commercial CI-V interfaces (such as the CT-17) are often overpriced or scarce. Moreover, the shift from legacy RS-232 serial ports to modern USB has complicated matters. This has led thousands of hams to search for one specific piece of information: the . +---------------+ | USB Connector | +---------------+ | |
Radio CI-V connector (3.5mm stereo): Tip – Data (open-collector) Ring – +5V or +8V (not always present) Sleeve – Ground Moreover, the shift from legacy RS-232 serial ports
| Symptom | Likely Cause | Fix | | :--- | :--- | :--- | | No communication | Baud rate mismatch | Set radio and COM port to same baud | | Intermittent control | Missing pull-up resistor (R1) | Add 4.7kΩ from CI-V to +5V | | Radio freezes when PC transmits | Bus contention (both trying to drive line) | Check Q1 – it should be open-collector, not push-pull | | Works on RX, not TX | Transistor Q1 connected backwards (C/E swapped) | Verify 2N3904 pinout: E-B-C (flat side facing you, left to right) | | USB device not recognized | FTDI counterfeit chip | Use official FTDI drivers or switch to CH340 |