ESP32 Forum

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#include <Wire.h>
#include <M5Stack.h>

int SLAVE_ADDRESS = 0x40;

void setup() {
  // put your setup code here, to run once:
  M5.begin();
  Wire.begin(SLAVE_ADDRESS);    //set slave address
  Wire.onReceive(receiveEvent); // register event
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:

  if (m5.BtnA.wasPressed()) {
    M5.Lcd.printf("hello");
  } else {
    M5.Lcd.printf("");
  }
  M5.update();

  delay(100);
}

void receiveEvent(int howMany) {
  
}

Code: Select all

Arduino：1.8.7 (Mac OS X), ボード："M5Stack-Core-ESP32, QIO, 80MHz, Default, 921600, None"

sketch/sketch_oct04a.ino.cpp.o:(.literal._Z5setupv+0x1c): undefined reference to `TwoWire::onReceive(void (*)(int))'
sketch/sketch_oct04a.ino.cpp.o: In function `setup()':
/Users/soichi/Documents/Arduino/sketch_oct04a/sketch_oct04a.ino:33: undefined reference to `TwoWire::onReceive(void (*)(int))'
collect2: error: ld returned 1 exit status