Test_I2C_UNO_PCF8574

#include <Wire.h>
int tempo1 = 150;
int tempo2 = 20;
//---------------------------
void setup()
{
  Serial.begin(115200);
  //Wire.begin(2, 0); // ESP8266
  //Wire.begin(13, 0); // ESP8266
  //Wire.begin(4, 12); // ESP8266
    Wire.begin();  // Arduino
}
//---------------------------
void loop()
{ //                                                // Se PCF8574A mude 38 para 20
  for (int i = 1; i < 256; )
  {
    Serial.println(i, HEX);
    //  int j = i<<4;
    Wire.beginTransmission(0x38);                   // Begin the transmission to PCF8574
    Wire.write(i);
    Wire.endTransmission();                         // End the Transmission
    delay(tempo1);                                   // Delay 1 seg
    i = i * 2;
  }
  for (int i = 1; i < 256; i++)
  {
    Serial.println(i, HEX);
    Wire.beginTransmission(0x38);                   // Begin the transmission to PCF8574
    Wire.write(i);                                  // Grava as portas
    Wire.endTransmission();                         // End the Transmission
    delay(tempo2);                                   // Delay 1 seg
  }


  /*                                                // Acende e apaga todos leds
    Wire.beginTransmission(0x38);                   // Begin the transmission to PCF8574
    Wire.write(0);                                  // Zera as portas
    Wire.endTransmission();                         // End the Transmission
    delay(1000);                                    // Delay 1 seg
    Wire.beginTransmission(0x38);                   // Begin the transmission to PCF8574
    Wire.write(0xFF);                               // Liga todas portas
    Wire.endTransmission();                         // End the Transmission
    delay(1000);                                    // Delay 1 seg
  */
}