Arduino I2C library test

/*


Test harness for playing with I2C.



*/

#include <I2C.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
#define END_MARKER         255


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

// function prototypes
int fillData(int bytes);


void setup()
{
    I2c.begin();
    I2c.setSpeed(1); // 0 = 100MHz, 1 = 400MHz
    Serial.begin(9600);
}

void loop()
{
    int total;
    int retries = 10;
    unsigned long start_time, trans_time;
    for(int i=0;i<retries;i++) {
        Serial.println("-----------------");
        Serial.println(retries++);
        Serial.println("-----------------");
        for (int bytes=1;bytes<MAX_PACKET_SIZE-1;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. Hacking a 0 as the first byte and forcing the
  // END_MARKER in. No error checking seeing we're interested in speed.

   data[bytes] = END_MARKER;
   I2c.write((int)SLAVE_ADDR, 0, data, bytes +1);
   Serial.print("Bytes: ");
   Serial.println(bytes + 2); // Includes the start byte and end marker
}