: A resistor (often around 4.7kΩ to 10kΩ) pulls the DATA line high when idle. Isolation & Protection :
: Since CI-V is a single-wire bus, you must connect the TXD and RXD pins of your USB chip together. A common method is connecting the RXD pin directly to the CI-V bus and using a 1N4148 diode icom ci v usb interface schematic top
The Icom CI-V USB interface is – it is a bidirectional, inverted, open-collector level converter. The top schematic presented here (USB serial chip → NPN inverter/open-collector → CI-V bus with pull-up) has become a de facto standard because: : A resistor (often around 4
Add a from the combined line to VCC (5V) to ensure the signal stays high when idle. The top schematic presented here (USB serial chip
: High-reliability designs often use a 7417 hex buffer IC as recommended in the ARRL Handbook to isolate the computer from the radio. Implementation Tips
: Connects to the PC; the converter chip is powered by the USB 5V line. Radio Side : Uses a 3.5mm mono phone plug . Tip : Data signal (bi-directional TTL). Sleeve : Ground reference. Icom IC7300 A to Z #27 CI-V Settings
