/*
 * sht30.c
 *
 *  Created on: Nov 3, 2022
 *      Author: Administrator
 */

#include <stdio.h>
#include "i2c.h"
#include "sht30.h"

#define CONFIG_SHT30_DEBUG

#ifdef CONGIF_SHT30_DEBUG
#define sht30_print(format, args...) printf(format, ##args)
#else
#define sht30_print(format, args...) do{} while(0)
#endif

static int sht30_send_cmd(SHT30_CMD cmd)
{
	uint8_t buf[2];

	buf[0] = cmd >> 8;
	buf[1] = cmd & 0xFF;

	return HAL_I2C_Master_Transmit(&hi2c2, SHT30_ADDR_WR, (uint8_t*)buf, 2, 0xFFFF);
}

static void sht30_soft_reset(void)
{
	sht30_send_cmd(SOFT_RESET_CMD);
	HAL_Delay(1);
}

static int sht30_single_shot_measurement(uint8_t *buf, uint8_t buf_size)
{
	uint16_t cmd = HIGH_ENABLED_CMD;
	uint8_t  rv;

	if( !buf || buf_size < SHT30_DATA_SIZE )
	{
		sht30_print("%s(): Invalid input argument\n", __func__);
		return -1;
	}

	rv = sht30_send_cmd(cmd);
	if( rv )
	{
		sht30_print("ERROR: HST30 send messurement command failure, rv = &d\n", rv);
		sht30_soft_reset();
		return -2;
	}

	rv = HAL_I2C_Master_Receive(&hi2c2, SHT30_ADDR_RD, buf, SHT30_DATA_SIZE, 0xFFFF);
	if(rv)
	{
		sht30_print("ERROR: SHT30 read measurement result failure, rv = %d\n", rv);
		return -3;
	}

	return 0;
}

static uint8_t sht30_crc8(const uint8_t *data, int len)
{
	const uint8_t POLYNOMIAL = 0x31;
	uint8_t       crc = 0xFF;
	int           i,j;

	for (i=0; i<len; ++i)
	{
		crc ^= *data++;

		for (j=0; j<8; j++)
		{
			crc = (crc & 0x80)? (crc << 1) ^ POLYNOMIAL:(crc << 1);
		}
	}
	return crc;
}

int SHT30_SampleData(float *temperature, float *humidity)
{
	uint8_t buf[SHT30_DATA_SIZE];
	int rv;
	uint16_t temp;
	uint16_t humd;
	uint16_t crc;

	if(!temperature || !humidity)
	{
		sht30_print("%s(): Invalid input argument\n", __func__);
		return -1;
	}

	rv = sht30_single_shot_measurement(buf, SHT30_DATA_SIZE);
	if(rv)
	{
		sht30_print("SHT30 Single Short measurement failure, rv=%d\n", rv);
		return -2;
	}

#ifdef CONFIG_SHT30_DEBUG
	{
		int i;

		sht30_print("SHT30 get %d bytes sample data: \n", SHT30_DATA_SIZE);
		for(i=0; i<SHT30_DATA_SIZE; i++)
		{
			sht30_print("0x%02x ", buf[i]);
		}
		sht30_print("\n");
	}
#endif

	crc = sht30_crc8(buf, 2);
	sht30_print("SHT30 temperature Cal_CRC: [%02x] EXP_CRC: [%02x]\n", crc, buf[2]);
	if(crc != buf[2])
	{
		sht30_print("SHT30 measurement temperature got CRC error\n");
		return -3;
	}

	crc = sht30_crc8(&buf[3], 2);
	sht30_print("SHT30 humidity Cal_CRC: [%02x] EXP_CRC: [%02x]\n", crc, buf[5]);
	if(crc != buf[5])
	{
		sht30_print("SHT30 messurement temperature got CRC error\n");
		return -4;
	}

	temp = (buf[0]<<8) | buf[1];
	humd = (buf[3]<<8) | buf[4];

	*temperature = -45 + 175*((float)temp/65535);
	*humidity = 100 * ((float)humd/65535);

	return 0;
}