/*********************************************************************************
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* Copyright: (C) 2019 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 API functions on RaspberryPi,
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* which connected to I2C-1
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*
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* Version: 1.0.0(04/07/19)
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* Author: Guo Wenxue <guowenxue@gmail.com>
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* ChangeLog: 1, Release initial version on "04/07/19 17:39:38"
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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 <errno.h>
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#include <time.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 <fcntl.h>
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#define TSL2561_I2C_ADDR 0x39
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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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/* 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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int tsl_fd = -1;
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static const int regs_addr[REG_COUNT]={DATA0LOW, DATA0HIGH, DATA1LOW, DATA1HIGH};
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#define msleep(x) usleep( 1000*(x) )
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int tsl2561_init(void)
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{
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if(tsl_fd > 0)
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return 0;
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if( (tsl_fd=open("/dev/i2c-1", O_RDWR)) < 0)
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{
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printf("TSL2561 I2C device setup failure: %s\n", strerror(errno));
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return -1;
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}
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printf("TSL2561 initialise ok, tsl_fd=%d\n", tsl_fd);
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return tsl_fd;
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}
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#define ON 1
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#define OFF 0
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void tsl2561_power(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_I2C_ADDR;
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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(tsl_fd, I2C_RDWR, &data) < 0 )
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{
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printf("%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(tsl_fd, I2C_RDWR, &data) < 0 )
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{
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printf("%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(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_I2C_ADDR;
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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(tsl_fd, I2C_RDWR, &data) < 0 )
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{
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printf("%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_I2C_ADDR;
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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(tsl_fd, I2C_RDWR, &data) < 0 )
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{
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printf("%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_get_lux(void)
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{
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int i;
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unsigned char reg_data[REG_COUNT];
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unsigned char buf;
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int chn0_data = 0;
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int chn1_data = 0;
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float div = 0.0;
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float lux = 0.0;
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tsl2561_power(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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tsl2561_readreg(regs_addr[i], ®_data[i]);
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}
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chn0_data = reg_data[1]*256 + reg_data[0]; /* Channel0 = DATA0HIGH<<8 + DATA0LOW */
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chn1_data = reg_data[3]*256 + reg_data[2]; /* channel1 = DATA1HIGH<<8 + DATA1LOW */
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if( chn0_data<=0 || chn1_data<0 )
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{
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lux = 0.0;
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goto OUT;
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}
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div = (float)chn1_data / (float)chn0_data;
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if( div>0 && div<=0.5 )
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lux = 0.304*chn0_data-0.062*chn0_data*pow(div,1.4);
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else if( div>0.5 && div<=0.61 )
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lux = 0.0224*chn0_data-0.031*chn1_data;
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else if( div>0.61 && div<=0.8 )
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lux = 0.0128*chn0_data-0.0153*chn1_data;
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else if( div>0.8 && div<=1.3 )
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lux = 0.00146*chn0_data-0.00112*chn1_data;
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else if( div>1.3 )
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lux = 0.0;
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OUT:
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printf("TSLl2561 get lux: %.3f\n", lux);
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tsl2561_power(OFF);
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}
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void print_datime(void)
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{
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time_t tmp;
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struct tm *p;
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time(&tmp);
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p=localtime(&tmp);
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printf("%d-%02d-%02d %02d:%02d:%02d\t", (p->tm_year+1900),(p->tm_mon+1),
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p->tm_mday, p->tm_hour, p->tm_min, p->tm_sec);
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}
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int main(int argc, char **argv)
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{
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int interval = 1;
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if( argc >= 2 )
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{
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interval = atoi(argv[1]);
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}
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tsl2561_init();
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while(1)
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{
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print_datime();
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tsl2561_get_lux();
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sleep(interval);
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}
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}
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