The MAX485 TTL to RS485 module Blue is a compact blue PCB that provides a straightforward interface between a microcontroller's TTL UART and an RS485 twowire data bus. Built around the MAX485 transceiver, this module enables reliable half‑duplex communication over twistedpair wiring, suitable for projects requiring robust long‑distance serial links. Key benefits Easy UART interface: DI accepts TTL serial data from a microcontroller and RO presents TTL data from the RS485 bus, simplifying integration with standard UART peripherals. Robust RS485 signaling: Uses differential A and B lines to improve noise immunity and allow longer cable runs in noisy environments. Simple control of transmit/receive: DE/RE together enable or disable the transmitter and receiver with a single control signal, facilitating straightforward half‑duplex operation. 5V logic compatibility: Designed for 5V TTL logic commonly found on microcontrollers and development boards. Compact blue module: Blue PCB design for easy identification and integration into prototypes and compact assemblies. Key attributes Functionality: TTL to RS485 transceiver module based on the MAX485, enabling bidirectional communication over a two‑wire RS485 bus in half‑duplex mode. Compatibility: Suitable for standard UART interfaces and 5V logic microcontrollers and single‑board computers that provide TTL level signals. Size and form: Compact module with a blue PCB suitable for quick prototyping and boardtoboard integration. Material: FR4 based board with standard surface finish and connectors typical of TTL to RS485 modules. Performance: Supports RS485 communication with data rates up to 2.5 Mbps under appropriate conditions, benefiting from differential signaling for improved reliability. Connections: VCC, GND, DI, RO, DE/RE, A, B pins available on the module to connect power, data lines, and the RS485 bus. Usage guidance Connect VCC to a +5V supply and GND to the system ground. Connect DI to the microcontroller's TX line and RO to the microcontroller's RX line. Use DE/RE as a control signal to enable transmission when sending data and to enable reception when not transmitting. Wire the RS485 bus with A and B lines to the remote RS485 devices, ensuring correct polarity (A to A, B to B). Use cases Microcontroller to RS485 sensor network: Interface a microcontroller (Arduino, ESP32, STM32, etc.) to a network of RS485 sensors or devices for data collection in an industrial or environmental monitoring setup. UART to RS485 gateway: Build a simple gateway that converts UART data to RS485 for logging or remote data transmission to a central controller or SCADA system. Remote device control over RS485: Extend a microcontroller's reach to remotely located actuators or controllers that communicate over RS485, enabling distributed control in robotics or automation projects. Notes This module emphasizes a straightforward, non‑isolated TTL to RS485 conversion suitable for hobbyist and prototype applications as well as lightweight embedded projects. Proper wiring and polarity of the RS485 A and B lines are essential for correct operation and to avoid communication errors. The MAX485 TTL to RS485 module Blue offers a practical, compact solution for adding RS485 capability to 5V microcontroller projects, with clear TTL‑level interfaces and a robust differential bus for reliable communication.