M5Paper: I2C アドレスのスキャン

m5paper_i2c_scan.ino

// ---------------------------------------------------------------
//	m5paper_i2c_scan.ino
//
//					Jun/6/2022
// ---------------------------------------------------------------
#include <M5EPD.h>
// I2C (internal) - SDA: 21, SCL: 22
// I2C (external - Port A) - SDA: 25, SCL: 32

M5EPD_Canvas canvas(&M5.EPD);
// ---------------------------------------------------------------
void setup()
{
	M5.begin();
	Wire1.begin(25, 32);

	M5.EPD.Clear(true);
	canvas.createCanvas(960, 540);
	canvas.setTextSize(5);

	canvas.drawString("m5paper_i2c_scan", 30, 100);
	canvas.pushCanvas(0,0,UPDATE_MODE_A2);
}

// ---------------------------------------------------------------
void loop()
{
	int address;
	int error;
	char buf[60];
	int aa[] = {0,0,0,0,0,0,0,0,0,0};

	Serial.println("Scanning internal I2C");
	canvas.drawString("Scanning internal I2C", 30, 150);
	canvas.pushCanvas(0,0,UPDATE_MODE_A2);
	
	for(address = 1; address < 127; address++)
	{
		Wire.beginTransmission(address);
		error = Wire.endTransmission();
		if(error == 0)
			{
			Serial.println(address, HEX);
			}
		delay(10);
	}
	delay(500);

	canvas.drawString("Scanning external I2C (PortA)", 30, 200);
	canvas.pushCanvas(0,0,UPDATE_MODE_A2);

	int nDevices = 0;
	Serial.println("Scanning external I2C (PortA)");
	for(address = 1; address < 127; address++)
	{
		Wire1.beginTransmission(address);
		error = Wire1.endTransmission();
		if(error == 0)
			{
			Serial.println(address, HEX);
			aa[nDevices] = address;
			nDevices++;
			}
		delay(10);
	}

	sprintf(buf, "aa[0] = %x", aa[0] );
	canvas.drawString(buf, 30, 250);
	sprintf(buf, "aa[1] = %x", aa[1] );
	canvas.drawString(buf, 430, 250);

	sprintf(buf, "aa[2] = %x", aa[2] );
	canvas.drawString(buf, 30, 300);
	sprintf(buf, "aa[3] = %x", aa[3] );
	canvas.drawString(buf, 430, 300);

	sprintf(buf, "nDevices = %d", nDevices );
	canvas.drawString(buf, 30, 350);
	canvas.pushCanvas(0,0,UPDATE_MODE_A2);


	delay(5000);
}

// ---------------------------------------------------------------

Arduino IDE

実行結果

Grove-LCD RGB Backlight を接続