#include <unistd.h>
#include <sys/ioctl.h>
#include <linux/i2c-dev.h>
#include <i2c/smbus.h>
#include <stdio.h>

#include "htu21d.h"

int i2cReset(int fd)
{
	if(ioctl(fd, I2C_SLAVE, ADDR) < 0)
	{
		perror("Failed to open the I2C bus: reset\n");
		return -1;
	}
	i2c_smbus_write_byte(fd, RESET);
	return 0;
}

//get temp
int getTemp(int fd, double *temp)
{
	char buffer[3];
	__s32 response = i2c_smbus_read_i2c_block_data(fd, TEMP, 3, buffer);
	if(response < 0) 
	{
		perror("failed to read temperature from sensor\n");
		return -1;
	}
	*temp = -46.85 + 175.72 * (buffer[0]*256+ buffer[1])/65536;
	return 0;

}

//get humidity