Arduino I2C Wire library test

/*


Test harness for playing with I2C.



*/

#include <Wire.h>

#define SLAVE_ADDR         0x01  // This has to match the address assigned to the slave in its code
#define MAX_PACKET_SIZE    16    // max bytes to test sending at a time
#define TEST_TRIES         10    // how many tests to perform for each number of bytes

// Holds the incoming data
byte data[MAX_PACKET_SIZE];

// function prototypes
int fillData(int bytes);
void sendData(int bytes);

void setup()
{
    Wire.begin();
    Serial.begin(9600);
}

void loop()
{
    int total;
    int bytes = 12;
    int retries = 0;
    unsigned long start_time, trans_time;
    for(;;) {
        Serial.println("-----------------");
        Serial.println(retries++);
        Serial.println("-----------------");
        for (bytes=1;bytes<MAX_PACKET_SIZE;bytes++){
            total = fillData(bytes);
            start_time = micros();
            sendData(bytes);
            trans_time = micros() - start_time;
            Serial.print("Total: ");
            Serial.println(total);
            Serial.print("Time: ");
            Serial.println(trans_time);
            delay(7000);
        }
    }

}


int fillData(int bytes)
{ // generate some random bytes.
    int total = 0;
    for (int i=0;i<bytes;i++) {
        data[i] = random(256);
        total += data[i];
    }
    return total;
}

void sendData(int bytes)
{ // send the bytes
   int i, bytes_sent=0;
   Wire.beginTransmission(SLAVE_ADDR);
   for (i=0;i<bytes;i++) {
       Wire.write(data[i]);
       bytes_sent++;
   }
   Wire.endTransmission();
   Serial.print("Bytes: ");
   Serial.println(bytes_sent);
}