Yahboom CH340G USB to TTL Module 3.3V/5V Selectable UART Serial Adapter with 4 DuPont Wires

Overview

The Yahboom USB to TTL module is a CH340/CH340G-based USB-to-UART serial communication adapter for programming, writing/downloading firmware, and general serial port communication/debugging. It uses a CH340 original chip (STC official recommended USB to TTL chip) for stable, high-speed operation and strong compatibility across different computers/drivers.

Key Features

• CH340 original chip (CH340/CH340G USB to TTL solution)
• Selectable output voltage: 3.3V or 5V (selected by shorting cap / short circuit cap)
• Status indicators: power indicator (PWR), TXD indicator, RXD indicator
• 6-pin TTL header labels: 5V, VCC, 3V3, TXD, RXD, GND
• Supported systems: Windows / macOS / Linux

Voltage Selection Notes (from provided instructions)

• 5V or 3V3 power supply can be selected by shorting circuit cap.
• The voltage selection of the short-circuit cap on the 6PIN pin:
• Connect 5V-VCC short circuited to 3V3-TTL output.
• Connect 3V3-VCC short circuited to 5V-TTL output.

Basic Use Notes (from provided instructions)

• The selection of 3V3 and 5V depends on the actual application environment. When the system is 3.3V, select 3V3, and when the system is 5V, select 5V.
• If the drive and wiring are correct, and the module cannot communicate normally, exchange the RXD and TXD lines and try again.
• Simple module test method: short-circuit TXD and RXD of the module, open a serial port debugging tool, and send data. Returning the original sample indicates the module is OK.

Specifications

Interface / Pinout

• USB interface
• 6-pin header: 5V, VCC, 3V3, TXD, RXD, GND

Applications

• Writing/communicate: can be used for writing firmware into an STM32 core board.
• Connect Bluetooth/WiFi module for communication: the computer USB is inserted into this module, and the module is connected to Bluetooth with DuPont cable; master/slave mode can be used to communicate with other Bluetooth devices.
• Serial port data debugging: connect to a micro-controller and sensor; a serial port debugging assistant can be used to read sensor data.

What's Included

• USB to TTL module x 1
• DuPont lines x 4

For wiring or compatibility questions (STM32/Raspberry Pi/Jetson Nano serial connections, jumper settings, and driver troubleshooting), contact support@rcdrone.top or visit https://rcdrone.top/.

Details

Built around the CH340/CH340G USB-to-UART chip for stable serial communication, flashing, and debugging on Windows, macOS, and Linux.

Use the 6-pin TTL header and DuPont wires to program STM32 core boards directly from a computer USB port.

A quick way to bridge a laptop USB port to Bluetooth/WiFi serial modules for configuration and data transfer.

Pair the adapter with a serial terminal to monitor TX/RX data streams while developing sensors or MCU projects.

Reference wiring examples for common platforms, including STM32, Raspberry Pi, and Jetson Nano UART connections.

Compact 52×16×8 mm USB-to-TTL module with selectable 3.3V/5V output via the shorting cap.

Clear pin labels and onboard PWR/TX/RX indicators make wiring and troubleshooting straightforward.

Select 3.3V or 5V to match your target, and loop TXD to RXD for a simple communication self-test.

Real-board views show the USB connector, the voltage-select jumper area, and the labeled 6-pin header for quick hookup.