/*********************************************************************************
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* Copyright: (C) 2023 LingYun IoT System Studio
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* All rights reserved.
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*
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* Filename: tsl2561.c
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* Description: This file is the Lux sensor TSL2561 code
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*
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* Version: 1.0.0(10/08/23)
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* Author: Guo Wenxue <guowenxue@gmail.com>
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* ChangeLog: 1, Release initial version on "10/08/23 17:52:00"
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*
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* Pin connection:
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* TSL2561 Module Raspberry Pi Board
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* VCC <-----> #Pin1(3.3V)
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* SDA0 <-----> #Pin27(SDA, BCM GPIO0)
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* SCL0 <-----> #Pin28(SCL, BCM GPIO1)
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* GND <-----> GND
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*
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* /boot/config.txt:
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* dtoverlay=i2c0,pins_0_1
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*
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********************************************************************************/
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#include <string.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <math.h>
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#include <time.h>
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#include <errno.h>
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#include <libgen.h>
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#include <getopt.h>
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#include <fcntl.h>
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#include <sys/ioctl.h>
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#include <linux/i2c.h>
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#include <linux/i2c-dev.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include "logger.h"
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#include "utils.h"
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#include "tsl2561.h"
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#define CONTROL_REG 0x80
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#define REG_COUNT 4
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#define POWER_UP 0x03
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#define POWER_DOWN 0x00
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#define OFF 0
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#define ON 1
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/* Register Address */
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enum
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{
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/* Channel_0 = DATA0HIGH<<8 + DATA0LOW */
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DATA0LOW = 0x8C,
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DATA0HIGH,
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/* Channel_1 = DATA1HIGH<<8 + DATA1LOW */
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DATA1LOW,
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DATA1HIGH,
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};
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static const int regs_addr[REG_COUNT]={DATA0LOW, DATA0HIGH, DATA1LOW, DATA1HIGH};
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void tsl2561_power(int fd, int cmd)
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{
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struct i2c_msg msg;
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struct i2c_rdwr_ioctl_data data;
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unsigned char buf[2];
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msg.addr= TSL2561_I2CADDR;
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msg.flags=0; /* write */
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msg.len= 1;
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msg.buf= buf;
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data.nmsgs= 1;
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data.msgs= &msg;
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msg.buf[0]=CONTROL_REG;
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if( ioctl(fd, I2C_RDWR, &data) < 0 )
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{
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log_error("%s() ioctl failure: %s\n", __func__, strerror(errno));
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return ;
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}
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if( cmd )
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msg.buf[0]=POWER_UP;
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else
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msg.buf[0]=POWER_DOWN;
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if( ioctl(fd, I2C_RDWR, &data) < 0 )
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{
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log_error("%s() ioctl failure: %s\n", __func__, strerror(errno));
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return ;
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}
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return ;
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}
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int tsl2561_readreg(int fd, unsigned char regaddr, unsigned char *regval)
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{
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struct i2c_msg msg;
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struct i2c_rdwr_ioctl_data data;
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unsigned char buf[2];
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msg.addr= TSL2561_I2CADDR;
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msg.flags=0; /* write */
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msg.len= 1;
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msg.buf= buf;
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msg.buf[0] = regaddr;
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data.nmsgs= 1;
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data.msgs= &msg;
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if( ioctl(fd, I2C_RDWR, &data) < 0 )
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{
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log_error("%s() ioctl failure: %s\n", __func__, strerror(errno));
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return -1;
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}
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memset(buf, 0, sizeof(buf));
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msg.addr= TSL2561_I2CADDR;
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msg.flags=I2C_M_RD; /* read */
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msg.len= 1;
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msg.buf= buf;
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data.nmsgs= 1;
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data.msgs= &msg;
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if( ioctl(fd, I2C_RDWR, &data) < 0 )
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{
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log_error("%s() ioctl failure: %s\n", __func__, strerror(errno));
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return -1;
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}
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*regval = msg.buf[0];
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return 0;
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}
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int tsl2561_sample_lux(float *lux)
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{
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int i, fd;
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int rv = 0;
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char *dev = TSL2561_I2CDEV;
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unsigned char reg_data[REG_COUNT];
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int ch0_data = 0;
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int ch1_data = 0;
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float ratio = 0.0;
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if( !lux )
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{
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log_error("Invalid input arguments\n");
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return -1;
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}
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if( (fd=open(dev, O_RDWR)) < 0)
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{
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log_error("i2c device '%s' open failed: %s\n", dev, strerror(errno));
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return -2;
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}
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tsl2561_power(fd, ON);
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msleep(410); /* t(CONV) MAX 400ms */
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/* Read register Channel0 and channel1 data from register */
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for(i=0; i<REG_COUNT; i++)
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{
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rv = tsl2561_readreg(fd, regs_addr[i], ®_data[i]);
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if( rv < 0)
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{
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log_error("TSL2561 read register failed\n");
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goto cleanup;
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}
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}
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rv = 0;
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ch0_data = (reg_data[1]<<8) + reg_data[0]; /* 通道0：可见光+红外 */
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ch1_data = (reg_data[3]<<8) + reg_data[2]; /* 通道1：仅红外 */
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/* 根据datasheet，饱和时光照强度很大 */
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if (ch0_data == 0xFFFF || ch1_data == 0xFFFF) {
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*lux = 50000.0;
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goto cleanup;
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}
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if (ch0_data == 0) { /* 无光照 */
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*lux = 0.0;
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goto cleanup;
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}
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ratio = (float)ch1_data / (float)ch0_data;
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if (ratio >= 0 && ratio <= 0.50) {
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*lux = 0.0304f * ch0_data - 0.062f * ch0_data * powf(ratio, 1.4f);
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}
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else if (ratio <= 0.61) {
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*lux = 0.0224f * ch0_data - 0.031f * ch1_data;
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}
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else if (ratio <= 0.80) {
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*lux = 0.0128f * ch0_data - 0.0153f * ch1_data;
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}
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else if (ratio <= 1.30) {
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*lux = 0.00146f * ch0_data - 0.00112f * ch1_data;
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}
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else { /* 超出有效范围 */
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*lux = 0.0;
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}
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if (*lux < 0) { /* 确保结果非负 */
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*lux = 0.0;
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}
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cleanup:
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tsl2561_power(fd, OFF);
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close(fd);
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return rv;
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}
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/**
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* @brief 采样TSL2561光照强度数据
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* @param lux 输出参数，存储计算后的光照强度值
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* @return int 0成功，-1失败
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*/
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#define SAMPLE_COUNT 5
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int tsl2561_get_lux(float *lux)
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{
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float samples[SAMPLE_COUNT];
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float current_lux, temp;
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int valid_samples = 0;
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int i,j;
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if (!lux) {
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log_error("Invalid input argument\n");
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return -1;
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}
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/* 采样N次数据 */
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for (i=0; i<SAMPLE_COUNT; i++)
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{
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if (tsl2561_sample_lux(¤t_lux) == 0) {
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samples[valid_samples++] = current_lux;
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}
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if (i < SAMPLE_COUNT-1) {
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msleep(100);
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}
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}
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if (valid_samples == 0)
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{
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log_error("All TSL2561 samples failed\n");
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return -2;
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}
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/* 只有一个有效采样，直接使用 */
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if (valid_samples == 1)
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{
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*lux = samples[0];
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return 0;
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}
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/* 对采样值进行排序 */
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for (i=0; i<valid_samples-1; i++) {
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for (j = i + 1; j < valid_samples; j++) {
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if (samples[i] > samples[j]) {
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temp = samples[i];
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samples[i] = samples[j];
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samples[j] = temp;
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}
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}
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}
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/* 取中位数 */
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*lux = samples[valid_samples / 2];
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return 0;
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}
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