USB-C to TTL CH340 UART Adapter Module User’s Guide
USB-C to TTL CH340 UART Adapter Module
User’s Guide
Overview
This adapter bridges USB-C ports on modern computers to TTL-level UART interfaces, enabling serial communication with microcontrollers like ESP32, STM32, ATtiny85, and Arduino. It uses the CH340G chip for USB-to-serial conversion.
Technical Specifications
| Feature | Details |
|---|---|
| USB Interface | USB Type-C |
| UART Voltage Levels | 3.3V or 5V (select via header pins) |
| Baud Rate Support | Up to 2 Mbps |
| Chipset | CH340G |
| Pins Exposed | TX, RX, VCC, GND, DTR (optional) |
| OS Compatibility | Windows, macOS, Linux |
Driver Installation
Windows
- Download driver from WCH official site.
- Install and reboot.
- Check COM port in Device Manager.
macOS
- Download from WCH site.
- Install and allow kernel extension in System Preferences → Security & Privacy.
Linux
Usually pre-installed. If needed:
sudo modprobe ch340
Wiring Guide
| CH340 Pin | Connects To Microcontroller |
|---|---|
| TX | RX |
| RX | TX |
| VCC | 3.3V or 5V (match logic level) |
| GND | GND |
| DTR | Optional (for auto-reset) |
Important: Always match the correct voltage levels to your circuit. Select 3.3V or 5V using the exposed PCB pads.
Usage Instructions
- Connect to PC via USB-C.
- Install driver if needed.
- Wire TX/RX/VCC/GND to your microcontroller.
- Open serial terminal (e.g., PuTTY, TeraTerm, Arduino IDE).
- Set baud rate (e.g., 9600, 115200) and COM port.
- Begin communication or upload firmware (if supported).
🛠️ Troubleshooting
| Problem | Solution |
|---|---|
| No COM port detected | Reinstall driver, try new cable |
| Garbage data in terminal | Check baud rate and TX/RX wiring |
| No response from device | Confirm voltage level and GND |
| Upload fails (Arduino) | Use DTR or press reset manually |
Advanced Tips
- Use DTR for auto-reset during flashing (especially for ESP32/ESP8266).
- For STM32, connect TX/RX to USART1 for bootloader flashing via STM32CubeProgrammer.
- For ATtiny85, use SoftwareSerial for debugging via this adapter.
- Combine with logic level shifter if working with mixed-voltage systems.