433 Mhz receiver doesn't get codes when LED matrix display is connected

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1

Hello!

I’m trying to use Arduino mega 2560, display with 433Mhz reciever and wireless trinket. Here’s my code.

#include <MD_MAX72xx.h>
#include <MD_Parola.h>
#include <SPI.h>
#include <RCSwitch.h>

#define HARDWARE_TYPE MD_MAX72XX::FC16_HW
#define MAX_DEVICES 16
#define CLK_PIN    52
#define DATA_PIN   51
#define CS_PIN     53
#define RF_RX_PIN  2 // Используем пин 2 для избежания конфликтов

MD_Parola myDisplay = MD_Parola(HARDWARE_TYPE, DATA_PIN, CLK_PIN, CS_PIN, MAX_DEVICES);
RCSwitch mySwitch = RCSwitch();

// Ваши коды кнопок
unsigned long buttonCodes[] = {5393, 5396, 5380, 5397};
const char* buttonNames[] = {"BTN1", "BTN2", "BTN3", "BTN4"};
int codeCount = 4;
unsigned long lastRFCheck = 0;
unsigned long lastDisplayUpdate = 0;
int currentDisplay = 0;

void setup() {
  Serial.begin(9600);
  Serial.println("Initializing system with your button codes...");
  
  // 1. Сначала инициализируем дисплей
  myDisplay.begin();
  myDisplay.setZone(0, 0, 15);
  myDisplay.setIntensity(10);
  myDisplay.displayClear();
  
  // 2. Затем RF приемник с задержкой
  delay(100);
  mySwitch.enableReceive(digitalPinToInterrupt(RF_RX_PIN));
  
  // 3. Показываем стартовое сообщение
  displayText("RF REMOTE READY");
  
  Serial.println("Button codes loaded:");
  for (int i = 0; i < codeCount; i++) {
    Serial.print("Button ");
    Serial.print(i + 1);
    Serial.print(": ");
    Serial.print(buttonCodes[i]);
    Serial.print(" (0x");
    Serial.print(buttonCodes[i], HEX);
    Serial.println(")");
  }
  Serial.println("Waiting for button presses...");
}

void displayText(const char* text) {
  myDisplay.displayClear();
  myDisplay.displayZoneText(0, text, PA_CENTER, 100, 0, PA_PRINT, PA_NO_EFFECT);
  myDisplay.displayAnimate();
}

void displayScrollText(const char* text) {
  myDisplay.displayZoneText(0, text, PA_LEFT, 60, 2000, PA_SCROLL_LEFT, PA_SCROLL_LEFT);
  while (!myDisplay.displayAnimate()) {
    delay(10);
  }
}

void handleRemoteCommand(unsigned long command) {
  Serial.print("RF Command received: ");
  Serial.print(command);
  Serial.print(" (0x");
  Serial.print(command, HEX);
  Serial.println(")");
  
  for (int i = 0; i < codeCount; i++) {
    if (buttonCodes[i] == command) {
      Serial.print(">>> Button ");
      Serial.print(i + 1);
      Serial.println(" pressed!");
      
      switch(i) {
        case 0: // Button 1 - 5393
          displayText("TEMP: 25C");
          Serial.println("Display: Temperature");
          break;
        case 1: // Button 2 - 5396
          displayText("TIME: 14:30");
          Serial.println("Display: Time");
          break;
        case 2: // Button 3 - 5380
          displayText("VOLT: 12.5V");
          Serial.println("Display: Voltage");
          break;
        case 3: // Button 4 - 5397
          displayScrollText("Hello! This is scrolling text from button 4 press ");
          Serial.println("Display: Scrolling text");
          break;
      }
      return;
    }
  }
  
  // Если код не распознан
  Serial.println(">>> Unknown button code!");
  char unknownMsg[25];
  sprintf(unknownMsg, "UNKNOWN: %lu", command);
  displayText(unknownMsg);
  delay(2000);
  displayText("PRESS KNOWN BTN");
}

void showDefaultMessages() {
  const char* messages[] = {
    "PRESS BUTTON 1",
    "FOR TEMPERATURE",
    "BUTTON 2: TIME",
    "BUTTON 3: VOLT",
    "BUTTON 4: TEXT"
  };
  
  static int msgIndex = 0;
  static unsigned long lastMsgChange = 0;
  
  if (millis() - lastMsgChange > 3000) {
    lastMsgChange = millis();
    displayText(messages[msgIndex]);
    msgIndex = (msgIndex + 1) % 5;
  }
}

void loop() {
  // Проверяем RF команды каждые 50мс
  if (mySwitch.available()) {
    unsigned long value = mySwitch.getReceivedValue();
    
    if (value != 0) {
      handleRemoteCommand(value);
    }
    
    mySwitch.resetAvailable();
    lastDisplayUpdate = millis(); // Сбрасываем таймер демо-режима
  }
  
  // Если прошло 10 секунд без команд, показываем демо-сообщения
  if (millis() - lastDisplayUpdate > 10000) {
    showDefaultMessages();
  }
  
  delay(50);
}

I wrote a code for determining button codes without using display (but it is connected all the time), and I got the codes.

But as soon as I code with using display, my 433 reciever refuses to get codes. What am I doing wrong? TIA

2

How did you determine that? Did you display the values returned? Did you add serial.Print() to track the functions and their return?

1 Like
3

Extremely unlikely. Suspect instead a code error on your part.

Describe what you expected to happen, what happens instead, and what you have done to debug the problem.

4

Probably not your issue, but I think correct parameters for hw spi would be

MD_Parola(HARDWARE_TYPE, CS_PIN, MAX_DEVICES);

5

Post your code and an annotated schematic showing all connections, grounds and power sources. Post links to each of the hardware devices giving technical information.