DIYables TTL to RS485 Module MAX3485 3.3V UART Converter for Arduino ESP32 STM32, 5 Pack
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Quick Overview
The DIYables MAX3485 TTL to RS485 Module converts 3.3V TTL UART serial signals into RS-485 differential signals using the MAX3485 transceiver, giving low voltage microcontrollers a robust way to communicate over long cable runs and in electrically noisy environments. Because the module runs directly at 3.3V, it connects straight to ESP32, STM32, and other 3.3V logic development boards without any level shifting parts in between.
Communication is half-duplex over the A and B differential lines, so a single twisted pair carries data in both directions between controllers, sensors, and remote devices. A dedicated EN pin keeps direction switching under firmware control, letting the microcontroller decide exactly when to drive the bus and when to listen. All connections are clearly labeled — VCC, GND, TXD, RXD, EN, A, and B — and the small PCB footprint fits tight enclosures and crowded prototyping setups.
Ideal for Modbus RTU links, multi-node RS-485 networks, industrial control panels, remote sensor monitoring, building automation, PLC interfacing, and any 3.3V embedded project that needs reliable serial communication beyond the reach of plain UART wiring.
Key Features
- MAX3485 RS485 Transceiver — MAX3485 chip converts 3.3V TTL UART serial signals to RS-485 differential signals for reliable long distance data links
- Native 3.3V Operation — Runs directly on 3.3V logic so it connects to ESP32, STM32, and 3.3V Arduino boards without level shifting circuitry
- Half-Duplex Communication — Two way RS-485 communication over a single A and B twisted pair for multi-device buses and daisy chained nodes
- Manual Direction Control — Dedicated EN pin gives the microcontroller precise firmware control over switching between transmit and receive modes
- Simple 7 Pin Interface — Clearly labeled VCC, GND, TXD, RXD, EN, A, and B connections for straightforward integration into an existing circuit
- Differential Noise Immunity — RS-485 differential signaling resists electrical noise, making it dependable in industrial and motor-driven environments
- Compact PCB Size — Small board footprint suits space constrained projects, tight enclosures, and dense prototyping boards
- Modbus RTU Ready — Works as the physical layer for Modbus RTU master or slave nodes and other RS-485 based protocols
- Wide Compatibility — Works with ESP32, STM32, 3.3V Arduino boards, Raspberry Pi, and any microcontroller with a 3.3V UART
- Versatile Applications — Suitable for industrial control, remote sensor monitoring, building automation, PLC interfacing, and embedded networking
- ...NOTE
- This module operates at 3.3V logic. Do not connect TXD, RXD, or EN directly to 5V logic pins without level shifting, and power VCC from a 3.3V supply.
- ...NOTE
SPECIFICATION
| Specification | Value |
|---|---|
| Product Type | TTL UART to RS485 Transceiver Converter Module |
| Chip | MAX3485 |
| Communication Mode | Half-duplex RS-485 |
| Operating Voltage | 3.3V DC |
| Logic Level | 3.3V TTL |
| TTL Side Pins | TXD, RXD, EN (direction control) |
| Power Pins | VCC, GND |
| RS485 Bus Terminals | A, B (differential pair) |
| Direction Control | Manual via EN pin |
| Package Quantity | 1 piece |
| Compatibility | ESP32, STM32, 3.3V Arduino boards, Raspberry Pi, 3.3V microcontrollers |
| Applications | Modbus RTU, RS-485 network, industrial control, remote sensors, building automation, PLC interfacing |
COMPATIBLE HARDWARE
- ESP32 development boards — 3.3V hardware UART with any GPIO driving the EN pin
- ESP32 C3 Super Mini — 3.3V UART with GPIO direction control
- STM32 boards (Blue Pill, Nucleo, etc.) — 3.3V USART with GPIO direction control
- Arduino Nano ESP32 — 3.3V UART with GPIO direction control
- Arduino Uno R4 WiFi/Minima — UART with level shifting to 3.3V on the TTL side
- ESP8266 boards (NodeMCU, Wemos D1, etc.) — 3.3V UART with GPIO direction control
- Raspberry Pi (all models) — 3.3V UART on GPIO header with GPIO EN switching
- Raspberry Pi Pico — 3.3V UART with GPIO direction control
- PLC RS485 ports and Modbus masters — standard A and B differential bus connection
- RS-485 sensors and Modbus slaves — multi-drop network nodes on the same twisted pair
- Any microcontroller with a 3.3V UART and a spare GPIO — TTL to RS-485 signal conversion
