ZY-MAX13487 ZY-MAX13488 Industrial Grade TTL to RS485 Transceiver Module Mini Half-Hole UART Serial Signal Conversion Board

📌 Industrial-Grade TTL to RS485 Transceiver Module | ZY-MAX485 / ZY-SP485

🔎 Product Overview

This is a mini industrial-grade TTL-RS485 conversion module built with original MAX485 / SP485 transceiver IC, designed for long-distance differential serial communication between MCU and 485 bus devices. Adopts half-hole gold-plated PCB craft & full SMT chip packaging, supports both SMT mass production and manual pin header soldering. All modules are packed in tape & reel for convenient storage and automated mounting.

📊 Core Specification Table

Item	Parameter Detail
Model	ZY-MAX485, ZY-SP485
Supply Voltage	DC 3V ~ 5.5V (3.3V / 5V MCU compatible)
Working Temperature	-40℃ ~ +85℃
Overall Dimension	14.8mm(L) × 11.5mm(W)
Single Module Weight	0.3g
Core Chip	Original MAX485 / SP485
Communication Mode	Half-duplex differential transmission
Max Transmission Distance	1200 Meters
Built-in Circuit	Auto TX/RX control circuit, 120Ω terminal matching resistor, power filter capacitor, bus pull-up/down resistors, transmission indicator LED
Surface Craft	Half-hole gold-plated pads
Packaging	Tape & reel packaging

📍 Pin Definition & Wiring Guide

All 8 half-hole pads are clearly labeled on PCB, matching wiring rules as below:

1. VCC: Power positive, connect to 3.3V / 5V power supply
2. GND: Common ground, connect system GND
3. TXD: TTL transmit pin, link to MCU UART TX pin
4. RXD: TTL receive pin, link to MCU UART RX pin
5. EN: Auto transceiver control pin, no extra IO operation required
6. A: RS485 bus A+ differential signal line
7. B: RS485 bus B- differential signal line

Two-Module Interconnection Rule

• TTL Side: VCC ↔ VCC, GND ↔ GND, TXD ↔ RXD, RXD ↔ TXD
• RS485 Bus Side: A ↔ A, B ↔ B
• For multi-node bus networking: Only install 120Ω matching resistor on the first & last module of the bus line

✨ Product Highlights

• ✅ Auto Transmit & Receive Design: Onboard EN pull-down circuit realizes automatic DE/RE switching, no extra MCU IO occupation, greatly simplifies program code
• ✅ Industrial Wide Temperature Range: Stable performance under -40℃ ~ +85℃ harsh environment, fit for outdoor & industrial control equipment
• ✅ Built-in Complete Peripheral Circuit: Integrated 120Ω terminal resistor, power filter, bus protection resistors, no extra external components needed
• ✅ Ultra Mini Size: 14.8*11.5mm tiny footprint, save PCB layout space for compact embedded devices
• ✅ Gold-Plated Half-Hole Pads: Dual use for SMT patch production and manual soldering debugging
• ✅ Strong Anti-Interference: Differential signal transmission, effectively resist electromagnetic interference in industrial scenarios

🛠 Wide Application Scenarios

1. Microcontroller Serial Communication: STM32, Arduino, ARM, MCU serial port convert to RS485 long-distance bus
2. Equipment Debug & Flashing: Car diagnostic, GPS module, XBOX360, DVD, hard disk repair, set-top box upgrade, radio modification
3. Industrial Control System: PLC, inverter, temperature controller, sensor data acquisition, multi-device bus networking
4. Serial Port Extension: Long-distance data transmission for intelligent agriculture, building security, laboratory instruments

⚠ Important Usage Notes

1. Do not cross-connect A and B bus lines, wrong wiring will cause complete communication failure
2. For bus over 300m long, only retain 120Ω resistor on the head & tail modules of the bus
3. Use shielded twisted pair cable in strong electromagnetic interference industrial environment, single-point grounding for shielding layer
4. Input voltage cannot exceed DC 5.5V, overvoltage will permanently damage the transceiver chip
5. This module supports half-duplex communication, only one-way data transmission at the same time, match response mechanism in communication protocol

📦 Packing Reminder

Kind reminder: If there are version differences or images not been updated, please refer to the actual product.