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USB TO UART solution with USB Type A connector





Industrial USB TO TTL Converter, Original CH343G Onboard, Multi-Protection & Systems Support.


  • Onboard resettable fuse and TVS diode, providing protections including over-current, over-voltage, backward-proof, and ESD protection, improving shock resistance, and safe and stable communications.
  • Onboard IO protection circuit for surge suppression.
  • Onboard TTL serial port 3.3V and 5V voltage level switch, allows selecting TTL level.
  • 3 x LED indicators for easily checking power connection and signal TX/RX statuses.
  • Quality plastic case with a dull-polish surface, well-crafted.
  • IDC connector with fool-proof design.


Name Parameters
Product Type USB to TTL
Supply Voltage 5V
Communication rate 50bps ~ 6Mbps
Serial port TTL level 5V/3.3V/2.5V/1.8V
Operating system Mac OS, Linux, Windows 11 / 10 / 8.1 / 8 / 7, Android

①: The onboard 5V/3.3V can be selected by the jumper cap, or the jumper cap can be unplugged, and the external voltage input can also be used (2.5V/1.8V, except industrial grade).


  • Product category: Industrial USB TO TTL converter
  • Host interface: USB
  • Device interface: UART
  • Communication range: 50bps ~ 6Mbps
  • USB Device Interface:
    • connector: USB Type-A;
    • Protection: resettable Fuse, ESD protection
  • UART interface:
    • connector: 6pin right-angle pinheader;
    • protection: IO protection diode
  • Indicator:
    • PWR: power indicator, turns red when USB voltage is detected
    • TXD: TX indicator, turns red while the USB port is sending data
    • RXD: RX indicator, turns red while the device port is receiving data



PIN Description
VCC 5V or 3.3V output for external device (configured by jumper)
GND Power gound
TXD Connects to MCU.RXD
RXD Connects to MCU.TXD
RTS# Connects to MCU.CTS
CTS# Connects to MCU.RTS
RI# MODEM contact input signal, ringing indication, active low
DCD# MODEM contact input signal, carrier detection, active low
DTR# MODEM contact output signal, data terminal ready, active low
DSR# MODEM contact input signal, data device ready, active low

About CH343

CH343 is a USB bus adapter chip, that realizes USB to a high-speed asynchronous serial port, and supports up to 115200bps communication Automatic identification and dynamic self-adaptation of baud rate, providing common MODEM contact signals for expanding asynchronous serial ports of computers, or feature USB bus for the common serial device or MCU.

How to use



The default driver of the computer is the CDC driver, which can be viewed through the device manager.
USB TO RS485 (B) 01.jpg
We default to software flow control. If you need to use CDC hardware flow, you need to connect the CFG of the board to EN (power-on self-test).

VCP Driver

The VCP driver is a manufacturer driver and needs to be installed by the user. After installation, it can be viewed through Device Manager.
USB TO RS485 (B) 02.jpg
The default is software flow control. If you need to use VCP hardware flow, you can open it directly through the serial debugging assistant.

Linxu/Raspberry Pi

To work with Raspberry Pi, it is driver-free, just connect and check with the following command:

ls /dev/tty*

USB TO RS485 (B) 03.jpg
The port should be named ttyACM0, user can use the minicom tool to test.

minicom -D /dev/ttyACM0


To use with MacOS, please download the driver and follow the guide:


To use with an Android device, please download the APP and test.

1. Open the APP and click to scan the device.        2. Click the scanned device.              3. Set the parameters to use.
USB TO 4CH TTL 0.png     Scanned1.png     CH343G Android2.png


Beware of knock-offs

Please note that we've found some poor copies of this item in the market. They are usually made of inferior materials and shipped without any testing.

You might be wondering if the one you're watching or you've purchased in other non-official stores is original, feel free to contact us.


The product can be selected by jumper caps for onboard 5V/3.3V, or it can be unplugged and input via external voltage as well (2.5V/1.8V).



Technical Support

If you need technical support or have any feedback/review, please click the Submit Now button to submit a ticket, Our support team will check and reply to you within 1 to 2 working days. Please be patient as we make every effort to help you to resolve the issue.
Working Time: 9 AM - 6 PM GMT+8 (Monday to Friday)