Tehnologie 
Gastronomie 
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Atelier 
Obiecte decorative 
Locuinţă 
Agrement 
I2C (I²C sau Inter-Integrated Circuit) este un tip de transmisie de date seriale de tip master-slave.
Pasul 1: Pinouts I2C
Arduino Diecimila/Duemilanove/Uno (poate si altele) nu au scrise pe ele care anume sunt pinii necesari protocolului I2C (sau TWI = Two Wire Interface) dar se pare ca, rasfoind documentatia am aflat ca pentru a folosi I2C/TWI avem nevoie sa conectam pinii SCL/SDA/+5V/GND intre device-uri.
La Arduino cele 2 porturi necesare sunt:
La Arduino cele 2 porturi necesare sunt:
SCL - Serial Clock Line - se afla pe pinul Analog 5
SDA - Serial Data Line - se afla pe pinul Analog 4
Pasul 2: Scanner de device-uri pe bus-ul I2C/TWI
Uneori nu stii exact ce adresa are un device asa ca e nevoie de un scanner. Se conecteaza cei 4 pini (+5V/GND/SCL/SDA) si se ruleaza pe Arduino codul de mai jos:
// i2c_scanner
//
// This program (or code that looks like it)
// can be found in many places.
// For example on the Arduino.cc forum.
// The original author is not know.
//
// This sketch tests the standard 7-bit addresses
// from 0 to 127. Devices with higher bit address
// might not be seen properly.
//
// Adapted to be as simple as possible by Arduino.cc user Krodal
#include <Wire.h>
void setup()
{
Wire.begin();
Serial.begin(115200);
Serial.println("\nI2C Scanner");
}
void loop()
{
byte error, address;
int nDevices;
Serial.println("Scanning...");
nDevices = 0;
for(address = 0; 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("Unknow 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");
delay(30000);
}
Pasul 3: Libraria Wire
Pentru a putea comunica cu device-ul de pe I2C/TWI e nevoie de libraria Wire.h:
http://arduino.cc/en/reference/wire .
