ChipScout

Communication

CH340G

USB-to-UART bridge chip used on many low-cost Arduino-compatible and ESP development boards.

China-madeWCHActiveModerate

Best For

Projects needing USB UART and Low cost with a commonly available communication part.

Avoid If

You need production-grade certainty without checking the exact module vendor, pinout, and library maintenance status.

Quick Decision Notes

CH340G is indexed as a communication part from WCH. ChipScout tracks it by practical maker-facing dimensions: interfaces, library readiness, estimated price, field-level sources, and whether the page is strong enough for selection rather than only lookup.

Technical Specifications

FunctionUSB to UARTSource: WCH
InterfaceUSB / UARTSource: WCH
USBFull speedSource: WCH
Working Voltage5V / 3.3V variantsSource: WCH

Common Use Cases

  • Maker prototypes
  • Low-cost modules
  • Educational hardware

Known Issues

  • Breakout boards may use different pin labels or regulator choices
  • Clone modules can differ from the original datasheet part

Interfaces and Library Support

Interfaces
USBUART
Wireless
None
Voltage
3.3V
Libraries
Arduino pendingMicroPython pending
Data Integrity86% confidence
Sourcehttps://www.wch-ic.com/
Last verified2026-05-20
Core specsVerified
PinoutAvailable
Library supportNeeds verification
Price rangePresent
Found a wrong spec?

Every field is meant to be source-backed. Corrections should include a datasheet URL, vendor page, module photo, or reproducible library test.

Submit correction

Source Resources

Datasheethttps://www.wch-ic.com/WCH

Pinout Table

VCCVCCPower · 3.3V / 5V · Match the target logic level.
GNDGNDPower · Common ground with target.
TXDTXDOutput · Connect to target RX.
RXDRXDInput · Connect to target TX.
DTRDTRControl · Optional auto-reset/boot control.

Pinout is not yet source-verified. Use the table as an integration checklist, then confirm exact pins against the module vendor page before wiring hardware.

Common Wiring

VCC

Power · 3.3V / 5V · Match the target logic level.

GND

Power · Common ground with target.

TXD

Output · Connect to target RX.

RXD

Input · Connect to target TX.

Arduino Example

Arduino support is not verified for this record yet. Add a library resource in the admin panel once a maintained driver or vendor SDK example is confirmed.

MicroPython Example

MicroPython support is pending. Treat community scripts as prototypes until a maintained driver is linked and tested on a known development board.

Recommended Development Boards

CH340G USB-UART module

Simple adapter for bootloader and serial logging validation.

ESP32 auto-program carrier

Use DTR/RTS transistor circuit for hands-free flashing.

Logic level marked adapter

Prefer adapters with explicit 3.3V/5V logic selection.

Alternative Model Reasons

CP2102CommunicationOften preferred when driver reliability or macOS behavior is a concern.
A7670CCommunicationChoose this when Arduino library maturity matters more than exact silicon match.
ATGM336HCommunicationChoose this when Arduino library maturity matters more than exact silicon match.
BC26CommunicationChoose this when Arduino library maturity matters more than exact silicon match.

Common Questions

What is CH340G best used for?

Projects needing USB UART and Low cost with a commonly available communication part.

Does CH340G support Arduino or MicroPython?

CH340G has Arduino support pending verification and MicroPython support pending verification.

What interfaces does CH340G use?

CH340G lists USB, UART; wireless support is no wireless protocol.

Compare CH340G vs CP2102

Alternatives and Related Parts

CP2102

Silicon Labs

USB-to-UART bridge widely used in development boards and debug adapters.

China-madeCommunication86% confidence

A7670C

SIMCom

4G Cat.1 cellular module used in low-cost IoT telemetry products.

China-madeCommunication74% confidence

ATGM336H

Zhongke Micro

China-made GNSS module commonly used as a low-cost GPS receiver in maker projects.

China-madeCommunication74% confidence

BC26

Quectel

NB-IoT module used for low-power cellular sensor applications.

China-madeCommunication72% confidence