Yahboom USB Multi-functional Serial Port Module USB-TTL/RS485 1.8/3.3/5V for STM32 ESP32 RPi Jetson RDK

Overview

Yahboom USB Multi-functional Serial Port Module is a serial communication module that combines three conversion modes on one compact board: USB to TTL, USB to RS485, and TTL to RS485. It supports selectable 1.8V/3.3V/5V TTL levels, RS485 hardware automatic transceiver direction switching, and high-speed communication for embedded development and industrial debugging with platforms such as STM32, ESP32, Raspberry Pi, Jetson, and RDK.

Key Features

• 3 operating modes via onboard switch: USB-TTL / USB-RS485 / TTL-RS485
• TTL voltage selection switch: 1V8 / 3V3 / 5V
• Professional TTL flow control: RTS (Request To Send) / CTS (Clear To Send)
• RS485 hardware automatic transceiver switching: automatic TX/RX direction control without software intervention
• Indicator lights: onboard power indicator and TX/RX transceiver indicator lights (three LED indicators)
• USB Type-C interface: supports reversible insertion
• Protection & reliability: onboard TVS protection (transient voltage suppressor), input reverse connection protection, RS485-A/B pin ESD protection, resettable fuse, anti-static protection diode
• CTS/RTS level note: when TTL voltage selection is set to 1.8V/3.3V, the CTS/RTS level is 3.3V; when set to 5V, the CTS/RTS level is 5V

Specifications

Interfaces / Pinout

• TTL header: 5V, GND, RXD, TXD, RTS, CTS
• RS485-side header: 3V3, GND, 485-B, 485-A, GND, 1V8
• Operating mode switch positions: TTL-485 / USB-485 / USB-TTL

Applications

• Microcontroller programming/download and UART debug printing (USB to TTL)
• PC/Linux controller to industrial sensors/PLCs communication (USB to RS485)
• TTL UART to RS485 conversion for MCU-to-RS485 networks (TTL to RS485)

What's Included

• USB Multi-functional Serial Port Module
• DuPont wires

Manuals & Tutorials

Tutorial resources and driver installation guidance are provided for this module. For pre-sales or technical support, contact support@rcdrone.top or visit https://rcdrone.top/.

Details

One compact board combines USB-to-TTL, USB-to-RS485, and TTL-to-RS485 conversion for embedded and industrial serial work.

Switch between conversion modes to cover microcontroller programming, UART log output, and RS485 device communication.

A simple onboard switch selects USB‑TTL, USB‑RS485, or TTL‑RS485 without rewiring the whole setup.

Selectable 1.8V/3.3V/5V TTL levels help match common boards like STM32, ESP32 and Raspberry Pi.

Onboard LEDs provide quick feedback for power and serial transmit/receive activity while debugging.

Use RTS/CTS hardware flow control when reliable high-speed UART transfer is required.

RS485 auto direction control reduces timing issues by switching between transmit and receive in hardware.

Clear pin labels make it easy to wire TTL (RXD/TXD/RTS/CTS) and RS485 (A/B) to your target device.

USB‑TTL mode supports MCU programming, serial console access, and debug printing over UART.

USB‑RS485 mode connects a computer to RS485 sensors, PLCs, and other long-distance bus devices.

TTL‑RS485 mode converts a controller’s UART into RS485 for robust multi-drop field wiring.

Protection parts such as TVS/ESD measures and a resettable fuse help improve reliability in lab and field use.

Reference dimensions and key electrical specs help confirm fit and compatibility before installation.

Choose the kit that matches your setup, from the module alone to wiring and a USB‑C data cable.