// Copyright 2007-2008 Xo W.
// Adapted from http://www.windmeadow.com/node/42
// Thanks to Chad for the great work!

#include <pic18.h>
#include "nunchuk.h"
#include "i2c/i2c.h"
#include "delay/delay.h"

unsigned char i;

void init_nunchuk (char* buf) {
    OpenI2C(MASTER, SLEW_OFF);
    SSPADD = 39;  // 300 kHz

    DelayMs(20); // 20 ms

    StartI2C();
    IdleI2C();
    WriteI2C(0xA4); // Slave address: 0x52, write mode
    IdleI2C();
    WriteI2C(0x40); // Memory address
    IdleI2C();
    WriteI2C(0x00); // Zero
    IdleI2C();
    StopI2C();

    DelayBigUs(998); // Delay 1 ms

    StartI2C();
    IdleI2C();
    WriteI2C(0xA5);  // Slave address: 0x52, read mode
    for(i = 0; i < (unsigned char)6; i++) {
        IdleI2C();
        buf[i] = ReadI2C();
        if (i < (unsigned char)6)
          AckI2C();
    }
    NotAckI2C();
    IdleI2C();
    StopI2C();
    
    DelayUs(27);
}

void read_nunchuk (char* buf) {
    StartI2C();
    IdleI2C();
    WriteI2C(0xA4); // Slave address: 0x52, write mode
    IdleI2C();
    WriteI2C(0x00); // Zero
    IdleI2C();
    StopI2C();
    
    DelayUs(158);
    
    StartI2C();
    IdleI2C();
    WriteI2C(0xA5);  // Slave address: 0x52, read mode
    for(i = 0; i < (unsigned char)6; i++) {
        IdleI2C();
        buf[i] = ReadI2C();
        if (i < (unsigned char)6)
            AckI2C();
    }
    NotAckI2C();
    IdleI2C();
    StopI2C();
}