CH340 USB to TTL Serial Converter Module
= Upgrade Download Board for STC Microcontrollers =
The CH340 module is a USB to TTL serial converter designed for programming, debugging, and communication with STC microcontrollers and other development boards. It provides a reliable and cost-effective bridge between USB and UART interfaces.
Simple USBtoSerial Bridge - Converts USB to TTL serial (UART) levels
Compatible with STC and Arduino - Ideal for programming microcontrollers
Operating voltage is 3.3V or 5V - selectable via jumper
Use RXD, TXD, VCC, and GND pins for connecting to target devices
Powering target from USB port may cause issues use external power for highcurrent targets
= Technical Specifications =
| Parameter | Value |
|---|
| Chip | CH340G |
| Interface | USB 2.0 to TTL UART |
| Operating Voltage | 3.3V or 5V (selectable) |
| Data Rate | 50bps to 2Mbps |
| Buffer Size | 16-byte TX/RX |
| LED Indicators | Power, TX, RX |
| Dimensions | 45mm x 17mm |
= Key Features =
Easy Setup - CH340 drivers available for Windows, Linux, and macOS
Selectable Voltage - 3.3V or 5V output for target board
Builtin LDO 3.3V / 5V voltage regulator for target board power
Onboard LEDs - Power, TX, and RX status indicators
Standard Pinout - Header pins for easy breadboard connection
== Applications ==
- STC MCU programming and firmware upgrades
- Arduino serial communication
- Serial console connection for Linux devices
- MIDI interface for synthesizers
- 3D printer and CNC control
- Sensor data logging via UART
Popular for STC programming - Reliable driver support
Easy to Use - No extra hardware required
√ Supported by major operating systems
√ Plugandplay driver installation on most platforms
√ Selectable output voltage for target board
= Connection Guide =
Standard pinout:
- GND: Ground connection to target
- RXD: Serial receive (connect to target TX)
- TXD: Serial transmit (connect to target RX)
- VCC: Power output (3.3V or 5V)
- RTS / CTS: Flow control (not used typically)
Use straight-through connection for Arduino (RX to TX, TX to RX)
Connect RXD of module to TXD of target for programming
Do not connect VCC to a target that is already powered
Use level shifting for 5V to 3.3V target devices
= Troubleshooting =
Driver not recognized:
- Download CH340 driver from official source
- Check driver installation in Device Manager
- Avoid using virtual machines for first-time setup
No serial communication:
- Check baud rate settings match target
- Verify correct port selected
- Ensure ground connection exists between module and target
Windows 10/11 driver issues:
- Use compatible driver (CH341SER or CH340)
- Disable driver signing in Test Mode for Windows 10
- Check Device Manager for driver conflicts
