The WCH CH340C is a USB-to-serial converter chip from Nanjing Qinheng Microelectronics (WCH), widely used for UART communication between computers and embedded devices. Unlike earlier CH340 variants, the CH340C includes an internal crystal oscillator, eliminating the need for an external crystal and reducing component count and cost. It supports standard serial interfaces and is commonly found on Arduino-compatible boards, development kits, and USB-to-TTL adapters. The CH340C is supported on Windows, Linux, and macOS with appropriate drivers, offering stable performance, low power consumption, and a compact design suitable for both hobbyist projects and professional embedded systems.