Using TwoWire I2C2 with esp32 & two pressure sensors

Projects Programming
10

Welcome to the forum.

Things are improving all the time. You don't have to use these anymore:

TwoWire I2C1 = TwoWire(0);

They are already in Wire.cpp here.

You can just use 'Wire' and "Wire1'.
If you want, then you can assign the pin numbers:

Wire1.begin( 19, 18);

But you can also use the default pins. I don't know the default pins for Wire1 :woozy_face: so I suggest you assign the pin numbers for Wire1.

This sketch scans both I2C buses:

#include <Wire.h>

void setup() 
{
  Serial.begin(115200);

  Wire.begin();             // default: 21, 22
  Wire1.begin( 19, 18);     // I don't know the default pins !

  Serial.println("---------- Scanning Wire -------------");
  I2C_ScannerWire();

  Serial.println("---------- Scanning Wire1 ------------");
  I2C_ScannerWire1();
}

void loop() { delay(10); }

void I2C_ScannerWire()
{
  byte error, address;
  int nDevices;

  Serial.println("Scanning...");

  nDevices = 0;
  for(address = 1; address < 127; address++ )
  {
    Wire.beginTransmission(address);
    error = Wire.endTransmission();

    if (error == 0)
    {
      Serial.print("I2C device found at address 0x");
      if (address<16)
        Serial.print("0");
      Serial.print(address,HEX);
      Serial.println("  !");

      nDevices++;
    }
    else if (error==4)
    {
      Serial.print("Unknown error at address 0x");
      if (address<16)
        Serial.print("0");
      Serial.println(address,HEX);
    }    
  }
  if (nDevices == 0)
    Serial.println("No I2C devices found\n");
  else
    Serial.println("done\n");
}

void I2C_ScannerWire1()
{
  byte error, address;
  int nDevices;

  Serial.println("Scanning...");

  nDevices = 0;
  for(address = 1; address < 127; address++ )
  {
    Wire1.beginTransmission(address);
    error = Wire1.endTransmission();

    if (error == 0)
    {
      Serial.print("I2C device found at address 0x");
      if (address<16)
        Serial.print("0");
      Serial.print(address,HEX);
      Serial.println("  !");

      nDevices++;
    }
    else if (error==4)
    {
      Serial.print("Unknown error at address 0x");
      if (address<16)
        Serial.print("0");
      Serial.println(address,HEX);
    }    
  }
  if (nDevices == 0)
    Serial.println("No I2C devices found\n");
  else
    Serial.println("done\n");
}

You can try the sketch in Wokwi simulation: