MAX485 module voor RS-485 communicatie over langere afstanden en meerdere eenheden op dezelfde bus.
SKU: OT5003 Número do artigo: AA119 EAN: 8720618231512 Localização: E06.06
Alternativa
Módulo serial MAX3232 RS232 para TTL
€ 1,80
Ver esta alternativa
Como ligar o Módulo Conversor MAX485 TTL para RS485 a um Arduino UNO ou ESP32, com um sketch de exemplo que podes carregar já.
This circuit interfaces an Arduino Uno with an RS-485 differential bus using the MAX485 transceiver. SoftwareSerial handles communication with the module, while digital pins control transmit and receive modes. Any message typed into the Serial Monitor is transmitted over RS-485, and incoming bus data is printed to the screen.
/*
* ==================================================================
* Generated by Codey.online — https://www.codey.online
* ==================================================================
* Project : MAX485 RS-485 Transceiver Communication
* Board : Arduino UNO (arduino:avr:uno)
* Parts : MAX485 TTL to RS485 Converter Module
* Libraries : none (built-in)
*
* Codey Online is an AI-powered browser IDE for Arduino and ESP32.
* Describe your project and Codey writes the code, draws the wiring
* diagram and uploads it to your board, straight from the browser.
* This code is free to use, modify and share, without warranty.
* ==================================================================
*/
#include <SoftwareSerial.h>
const byte PIN_RO = 2; // Receiver Out (RX)
const byte PIN_DI = 3; // Driver In (TX)
const byte PIN_DE = 4; // Driver Enable (Active HIGH)
const byte PIN_RE = 5; // Receiver Enable (Active LOW)
SoftwareSerial rs485(PIN_RO, PIN_DI);
unsigned long lastSend = 0;
int packetCount = 0;
void setTransmitMode() {
digitalWrite(PIN_RE, HIGH); // Disable receiver
digitalWrite(PIN_DE, HIGH); // Enable driver
delayMicroseconds(50);
}
void setReceiveMode() {
digitalWrite(PIN_DE, LOW); // Disable driver
digitalWrite(PIN_RE, LOW); // Enable receiver
delayMicroseconds(50);
}
void rs485Send(const String &msg) {
setTransmitMode();
rs485.println(msg);
rs485.flush();
setReceiveMode();
}
void setup() {
pinMode(PIN_DE, OUTPUT);
pinMode(PIN_RE, OUTPUT);
setReceiveMode();
Serial.begin(115200);
rs485.begin(9600);
Serial.println(F("MAX485 RS-485 Transceiver Demo"));
Serial.println(F("Type a message and press Enter to send over RS-485."));
}
void loop() {
// Forward incoming Serial Monitor input to RS-485
if (Serial.available()) {
String input = Serial.readStringUntil('\n');
input.trim();
if (input.length() > 0) {
Serial.print(F("Sending: "));
Serial.println(input);
rs485Send(input);
}
}
// Forward received RS-485 data to Serial Monitor
if (rs485.available()) {
Serial.print(F("Received: "));
while (rs485.available()) {
char c = (char)rs485.read();
Serial.print(c);
delay(2);
}
Serial.println();
}
// Automatically send a heartbeat packet every 5 seconds
if (millis() - lastSend >= 5000) {
lastSend = millis();
packetCount++;
String packet = "Ping #" + String(packetCount);
Serial.print(F("Auto-transmitting: "));
Serial.println(packet);
rs485Send(packet);
}
}
Wiring diagram and example code generated by Codey.online — https://www.codey.online
This project demonstrates sending and receiving data over an RS-485 bus using the MAX485 module and ESP32 UART2. The ESP32 switches the DE/RE pins HIGH to transmit a periodic heartbeat message and sets them LOW to listen for incoming RS-485 packets. A simple 1kΩ/2kΩ voltage divider safely drops the 5V TTL output (RO) of the module to 3.3V for the ESP32 RX pin.
/*
* ==================================================================
* Generated by Codey.online — https://www.codey.online
* ==================================================================
* Project : MAX485 RS-485 Communication with ESP32
* Board : ESP32 DEVKIT V1 (esp32:esp32:esp32doit-devkit-v1)
* Parts : MAX485 TTL to RS485 Converter Module
* Libraries : none (built-in)
*
* Codey Online is an AI-powered browser IDE for Arduino and ESP32.
* Describe your project and Codey writes the code, draws the wiring
* diagram and uploads it to your board, straight from the browser.
* This code is free to use, modify and share, without warranty.
* ==================================================================
*/
// MAX485 TTL to RS-485 transceiver demo with ESP32
const int CONTROL_PIN = 4; // Controls DE and RE (HIGH = Transmit, LOW = Receive)
const int RXD2_PIN = 16;
const int TXD2_PIN = 17;
unsigned long lastSendTime = 0;
int messageCount = 0;
void setup() {
Serial.begin(115200);
pinMode(CONTROL_PIN, OUTPUT);
digitalWrite(CONTROL_PIN, LOW); // Start in receive mode
// Initialize UART2 for RS-485 communication
Serial2.begin(9600, SERIAL_8N1, RXD2_PIN, TXD2_PIN);
Serial.println("RS-485 Transceiver Ready");
}
void loop() {
// Send a message every 2 seconds
if (millis() - lastSendTime >= 2000) {
lastSendTime = millis();
messageCount++;
// Enable RS-485 transmitter
digitalWrite(CONTROL_PIN, HIGH);
delay(10);
String msg = "Hello from ESP32 #" + String(messageCount);
Serial2.println(msg);
Serial2.flush(); // Wait until all outgoing bytes are transmitted
// Return to receive mode
digitalWrite(CONTROL_PIN, LOW);
Serial.print("Sent over RS-485: ");
Serial.println(msg);
}
// Check for incoming RS-485 data
if (Serial2.available()) {
Serial.print("Received via RS-485: ");
while (Serial2.available()) {
char c = (char)Serial2.read();
Serial.print(c);
}
Serial.println();
}
}
Wiring diagram and example code generated by Codey.online — https://www.codey.online
Módulo MAX485 com o chip MAX485, de baixo consumo de energia para comunicação RS-485. O RS485 é usado para comunicação serial a distâncias maiores do que RS232 ou TTL diretas e suporta várias unidades no mesmo barramento.
Especificações do módulo MAX485:
– Funciona em: 5V.
– Ligação onboard para fios RS-485.
– Dimensões: 44mm x 14mm.
Dimensões
Comprimento: 4,39cm
Largura: 1,41cm
Altura: 1,89cm

| Largura | 1,41cm |
|---|---|
| Tensão de trabalho | 5V |
| Comprimento | 4,39cm |
| Altura | 1,89cm |
Parto do princípio de que funciona tão bem quanto o módulo Rs232. Encomendei este módulo 485 para, daqui a algum tempo, ligar um inversor híbrido easun a um arduino. Portanto, ainda não o utilizei.
Padrão, o que há para dizer sobre isso?
Não ficas satisfeito? Tens 30 dias após a receção para devolver o produto.
Tudo sobre devoluções
Módulo Conversor MAX485 TTL para RS485