The Pololu USB-to-serial adapter is a tiny unit that makes it easy to connect a microcontroller project to a PC. You can connect the adapter directly to a microcontroller without an RS-232-to-TTL level converter. It is USB 2.0-compatible and will work with your existing programs that interface with a serial port.
The Pololu USB-to-serial adapter is great for connecting microcontroller projects to a personal computer. The adapter uses 3.3 V signal levels so you can connect it directly to any microcontroller running at up to 5 V without the hassle of an RS-232-to-TTL level converter. The tiny unit is only 1.0" x 0.65" including its mini-B connector, and the simple layout of the ground, transmit, and receive lines allows for easy mounting that takes up as little as four breadboard rows.
The USB adapter’s drivers make it look like a standard serial port to the operating system, allowing you to connect to all of your existing software, such as servo controller interface programs, through a USB port. The adapter is compatible with USB 2.0 standards and allows baud rates of up to 921.6 kbps. Drivers are available for Windows 98 through Vista, Linux, and Mac OSX.
With the trend toward removing serial ports from new computers, the Pololu USB-to-serial adapter provides one of the most economical, small, and simple solutions to the common problem of interfacing small projects to PCs.
Note: This product does not include printed documentation or software discs. The Pololu USB-to-serial adapter requires software drivers to operate; please see the resources tab for more information. This product requires a USB A to mini-B cable (not included) to connect to a computer.
![]() |
| Pin | Type | Function |
|---|---|---|
| DCD | In | "Data carrier detect" control input (active low) |
| DTR | Out | "Data terminal ready" control output (active low) (often used with DSR) |
| DSR | In | "Data set ready" control input (active low) (often used with DTR) |
| RTS | Out | "Ready to send" control output (often used with CTS) |
| CTS | In | "Clear to send" control input (often used with RTS) |
| GND | Power | Ground |
| TX | Out | Asynchronous serial data transmit (idle high) |
| VBUS | Power | USB bus voltage (+5V) |
| RX | In | Asynchronous serial data receive |
| SUSPEND | Out | Driven high when in USB suspend state |
| SUSPEND | Out | Driven low when in USB suspend state |
| RST | In | Device reset |
| RI | In | "Ring indicator" control input (active low) |
| VDD | Power | 3.3 V voltage regulator output |
To connect a serial device to your computer’s USB port, you will most likely only need to use the GND, TX, and RX lines. The TX and RX lines use 3.3-volt levels, but the USB adapter input lines will tolerate up to 5.5 volts. Therefore, a direct connection to a microcontroller’s I/O lines is usually possible.
For some programs, it will be necessary to connect the handshaking lines (RTS, CTS, etc.) if the software does not establish a connection without those lines. In general, the handshaking lines can be left disconnected, used for their intended purpose, or used as additional I/O lines to the computer.
![]() |
USB Cable A to Mini-B 6 ft. |
Manufacturer BTC Korporacja sp. z o. o. Lwowska 5 05-120 Legionowo Poland sprzedaz@kamami.pl 22 767 36 20
Responsible person BTC Korporacja sp. z o. o. Lwowska 5 05-120 Legionowo Poland sprzedaz@kamami.pl 22 767 36 20
Cable with USB plugs type A and mini-USB type B, cable with a length of 1.8 m
No product available!
USB-UART TTL converter based on the CH343G chip. Equipped with a number of security features ensuring stable and safe communication. Waveshare CH343 USB UART Board (type A)
USB TO UART solution with USB Type A connector
Converter dedicated to industrial applications. It provides communication between the USB interface and the RS422 and RS485 serial standard
No product available!
USB - UART converter based on the FT232RL chip. Compatible with voltages of 3.3 V and 5 V, has been equipped with a USB type C connector. Waveshare FT232 USB UART Board (Type C)
KAmod USB-UART-mini is a compact USB-C to UART converter, based on the FT230XS chip, enabling communication at speeds from 300 bps to 3 Mbps and providing the option of mounting using an additional front panel; includes LED indicators, supports signal voltages of 3.3 V, optionally 5 V, and offers support for Windows, Linux and Mac
The Adafruit CH9328 UART to HID Keyboard Breakout allows for easy and fast emulation of a HID keyboard without the need for a microcontroller with native USB. The module is used in prototyping projects, automation, integration with single-board computers and in testing devices where keyboard signals are required. Thanks to support for various transmission modes and simplicity of integration, it is a practical tool for electronics engineers and embedded system programmers. Adafruit 5973
No product available!
UART converter - USB based on the FT232RL system with TX, RX, RTS and CTS lines led out to the goldpin female connector. It uses a mini USB connector. Adafruit 284
WIFI-LPT100 Eval Kit module enables UART data transmission via WiFi, ultra low power consumption, encrypted communication
No product available!
USB - UART converter based on the PL2303GS chip. Compatible with 1.8 V, 2.5 V, 3.3 V and 5 V, it is equipped with a mini USB connector. Waveshare PL2303 USB UART Board (mini) V2
USB - UART converter based on the CH9102F chip. Compatible with the voltage of 3.3 V and 5 V, it has been equipped with a USB type C connector. Adafruit 5568
KAmod RS232S-ALL is a 3-5.5V RS232 to TTL converter supporting all RS232 signals, offering standard DB9 and Phoenix MC 3.81 connectors and 2.54mm goldpins, based on the MAX3238/SP3238 and providing ESD protection up to 15kV
USB - RS-232 USB A (m) / D-Sub (m) cable with a length of 1 m. Akyga AK-CO-02
A small USB-UART TTL converter module based on the CH340 system with a USB type A connector. Designed for the ESP-01 and ESP-01S modules
USB - UART converter based on the PL2303 chip. Compatible with voltages of 1.8 V, 2.5 V, 3.3 V and 5 V, it is equipped with a USB type A connector. Waveshare PL2303 USB UART Board (type A) V2
RS232 - UART converter based on the MAX3238 chip. It uses all lines of the RS232 interface, thanks to which the user has all the standard\'s functionalities at his disposal. Pololu 126
No product available!