Note: Some variant cables use a 4-contact TRRS plug, but only the first 3 contacts (Tip, Ring 1, and Sleeve) are utilized. A standard 3.5 mm stereo TRS plug works perfectly. 🛠️ DIY: How to Build Your Own KT-8900 Cable
If you want to build your own cable rather than purchasing a QYT USB cable , you will need a USB-to-TTL UART module. qyt kt8900 programming cable pinout top
Note: If using a USB-to-TTL adapter (like a CP2102), ensure your TX wire connects to the radio's RX pin and vice versa. 🎤 Microphone Port Pinout (RJ45) If you are looking to interface with the front RJ45 microphone port for other projects, here is the standard layout: QYT Radios Description Data Input Auxiliary data Repeater control Microphone audio input MIC Ground Ground for audio Push-to-Talk Main chassis ground +8V DC Out Low current power for mic Not connected ⚠️ Pro-Tips for Successful Programming Note: Some variant cables use a 4-contact TRRS
If you are DIY-ing a cable using a standard USB-to-TTL serial adapter (like an FTDI or CH340 board), the connections to the 3.5mm plug are as follows: RX (Data Receive) TX (Data Transmit) GND (Ground) Digirig Forum Note on Connector Fit: Note: If using a USB-to-TTL adapter (like a