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guowenxue

2024-03-12 8df7c2928393a804db45a685311df14bf8a76f45

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d6b4a7	1	/*********************************************************************************
G	2	* Copyright: (C) 2023 LingYun IoT System Studio
	3	* All rights reserved.
	4	*
	5	* Filename: sht20.c
	6	* Description: This file is temperature and relative humidity sensor SHT20 code
	7	*
	8	* Version: 1.0.0(10/08/23)
	9	* Author: Guo Wenxue <guowenxue@gmail.com>
	10	* ChangeLog: 1, Release initial version on "10/08/23 17:52:00"
	11	*
	12	* Pin connection:
	13	* STH20 Module Raspberry Pi Board
	14	* VCC <-----> #Pin1(3.3V)
	15	* SDA <-----> #Pin3(SDA, BCM GPIO2)
	16	* SCL <-----> #Pin5(SCL, BCM GPIO3)
	17	* GND <-----> GND
	18	*
	19	* /boot/config.txt:
	20	* dtoverlay=i2c1,pins_2_3
	21	*
	22	********************************************************************************/
	23	#include <stdio.h>
	24	#include <stdlib.h>
	25	#include <string.h>
	26	#include <stdint.h>
	27	#include <string.h>
	28	#include <unistd.h>
	29	#include <libgen.h>
	30	#include <getopt.h>
	31	#include <time.h>
	32	#include <errno.h>
	33	#include <fcntl.h>
	34	#include <sys/ioctl.h>
	35	#include <sys/types.h>
	36	#include <sys/stat.h>
	37	#include <linux/types.h>
	38	#include <linux/i2c.h>
	39	#include <linux/i2c-dev.h>
	40
c5e9e8	41	/* SHT2X 7-bit I2C slave address */
G	42	#define SHT2X_CHIPADDR 0x40
	43
	44	/* SHT2X trigger command */
	45	#define SOFTRESET 0xFE
	46	#define TRIGGER_TEMPERATURE_NO_HOLD 0xF3
	47	#define TRIGGER_HUMIDITY_NO_HOLD 0xF5
	48
	49	/* Linux /dev/i2c-x device program API mode */
	50	enum
	51	{
	52	MODE_IOCTL, /* I2C device API use ioctl() */
	53	MODE_RDWR, /* I2C device API use read()/write() */
	54	};
	55
	56	typedef struct sht2x_s
	57	{
	58	char dev; / SHT20 connect I2C device, /dev/i2c-N */
	59	int addr; /* SHT20 7-bits slave address */
	60	int fd; /* File description */
	61	int mode; /* I2C device API use read/write or ioctl mode */
	62	} sht2x_t;
	63
	64	int sht2x_init(sht2x_t *sht2x);
	65	int sht2x_get_serialnumber(sht2x_t sht2x, uint8_t serialnumber, int size);
	66	int sht2x_get_temp_humidity(sht2x_t sht2x, float temp, float *rh);
	67
d6b4a7	68	static inline void msleep(unsigned long ms);
G	69	static inline void dump_buf(const char prompt, uint8_t buf, int size);
c5e9e8	70	static int i2c_write(sht2x_t sht2x, uint8_t data, int len);
G	71	static int i2c_read(sht2x_t sht2x, uint8_t buf, int size);
d6b4a7	72
G	73	static inline void banner(const char *progname)
	74	{
	75	printf("%s program Version v1.0.0\n", progname);
	76	printf("Copyright (C) 2023 LingYun IoT System Studio.\n");
	77	}
	78
	79	static void program_usage(const char *progname)
	80	{
	81
	82	printf("Usage: %s [OPTION]...\n", progname);
	83	printf(" %s is SHT20 temperature and humidity sensor program. \n", progname);
	84
	85	printf(" -d[device ] Specify I2C device, such as /dev/i2c-1\n");
c5e9e8	86	printf(" -m[mode ] Specify API mode, 0 for ioctl and 1 for read()/write()\n");
d6b4a7	87	printf(" -h[help ] Display this help information\n");
G	88	printf(" -v[version ] Display the program version\n");
	89
	90	printf("\n");
	91	banner(progname);
	92	return;
	93	}
	94
	95	int main(int argc, char **argv)
	96	{
c5e9e8	97	int rv;
d6b4a7	98	float temp, rh;
c5e9e8	99	uint8_t serialnumber[8];
G	100	char *progname=NULL;
	101	sht2x_t sht2x;
d6b4a7	102
G	103	struct option long_options[] = {
	104	{"device", required_argument, NULL, 'd'},
c5e9e8	105	{"mode", required_argument, NULL, 'm'},
d6b4a7	106	{"version", no_argument, NULL, 'v'},
G	107	{"help", no_argument, NULL, 'h'},
	108	{NULL, 0, NULL, 0}
	109	};
	110
	111	progname = basename(argv[0]);
	112
c5e9e8	113	memset(&sht2x, 0, sizeof(sht2x));
G	114	sht2x.addr = SHT2X_CHIPADDR;
	115	sht2x.dev = "/dev/i2c-1";
	116
d6b4a7	117	/* Parser the command line parameters */
c5e9e8	118	while ((rv = getopt_long(argc, argv, "d:m:vh", long_options, NULL)) != -1)
d6b4a7	119	{
G	120	switch (rv)
	121	{
	122	case 'd': /* Set I2C device path: /dev/i2c-1 */
c5e9e8	123	sht2x.dev = optarg;
G	124	break;
	125
	126	case 'm': /* Set I2C API mode: 0,1 */
	127	sht2x.mode = atoi(optarg) ? MODE_RDWR : MODE_IOCTL;
d6b4a7	128	break;
G	129
	130	case 'v': /* Get software version */
	131	banner(progname);
	132	return EXIT_SUCCESS;
	133
	134	case 'h': /* Get help information */
	135	program_usage(progname);
	136	return 0;
	137
	138	default:
	139	break;
	140	}
	141	}
	142
c5e9e8	143	if( sht2x_init(&sht2x) < 0 )
d6b4a7	144	{
c5e9e8	145	printf("SHT2x initialize failure, maybe device not present!\n");
G	146	return 1;
	147	}
	148
	149	if( sht2x_get_serialnumber(&sht2x, serialnumber, 8) < 0)
	150	{
	151	printf("SHT2x get serial number failure\n");
	152	return 3;
	153	}
	154
	155	if( sht2x_get_temp_humidity(&sht2x, &temp, &rh) < 0 )
	156	{
	157	printf("SHT2x get get temperature and relative humidity failure\n");
	158	return 3;
	159	}
	160
	161	printf("Temperature=%lf ℃ relative humidity=%lf.\n", temp, rh);
	162
	163	close(sht2x.fd);
	164	}
	165
	166	int sht2x_softreset(sht2x_t *sht2x)
	167	{
	168	uint8_t buf[1];
	169
	170	if( !sht2x \|\| sht2x->fd<0 )
	171	{
	172	printf("%s line [%d] %s() get invalid input arguments\n", __FILE__, __LINE__, __func__ );
d6b4a7	173	return -1;
G	174	}
	175
c5e9e8	176	/* software reset SHT2x */
G	177	buf[0] = SOFTRESET;
	178	if( i2c_write(sht2x, buf, 1) < 0 )
	179	{
	180	return -2;
	181	}
d6b4a7	182
G	183	msleep(50);
	184
c5e9e8	185	return 0;
G	186	}
d6b4a7	187
c5e9e8	188	int sht2x_init(sht2x_t *sht2x)
G	189	{
	190	if( (sht2x->fd=open(sht2x->dev, O_RDWR)) < 0)
	191	{
	192	printf("i2c device open failed: %s\n", strerror(errno));
	193	return -1;
	194	}
d6b4a7	195
c5e9e8	196	if( MODE_RDWR == sht2x->mode )
G	197	{
	198	/* set I2C mode and SHT2x slave address */
	199	ioctl(sht2x->fd, I2C_TENBIT, 0); /* Not 10-bit but 7-bit mode */
	200	ioctl(sht2x->fd, I2C_SLAVE, SHT2X_CHIPADDR); /* set SHT2x slave address 0x40*/
	201	}
	202
	203	if( sht2x_softreset(sht2x) < 0 )
	204	{
	205	printf("SHT2x softreset failure\n");
	206	return -2;
	207	}
	208
	209	return 0;
	210	}
	211
	212	int sht2x_get_temp_humidity(sht2x_t sht2x, float temp, float *rh)
	213	{
	214	uint8_t buf[4];
	215
	216	if( !sht2x \|\| !temp \|\| !rh \|\| sht2x->fd<0 )
	217	{
	218	printf("%s line [%d] %s() get invalid input arguments\n", __FILE__, __LINE__, __func__ );
	219	return -1;
	220	}
	221
	222	/* send trigger temperature measure command and read the data */
	223	memset(buf, 0, sizeof(buf));
	224	buf[0]=TRIGGER_TEMPERATURE_NO_HOLD;
	225	i2c_write(sht2x, buf, 1);
d6b4a7	226
G	227	msleep(85); /* datasheet: typ=66, max=85 */
	228
	229	memset(buf, 0, sizeof(buf));
c5e9e8	230	i2c_read(sht2x, buf, 3);
d6b4a7	231	dump_buf("Temperature sample data: ", buf, 3);
c5e9e8	232	temp = 175.72 (((((int) buf[0]) << 8) + buf[1]) / 65536.0) - 46.85;
d6b4a7	233
c5e9e8	234	/* send trigger humidity measure command and read the data */
G	235	memset(buf, 0, sizeof(buf));
	236	buf[0] = TRIGGER_HUMIDITY_NO_HOLD;
	237	i2c_write(sht2x, buf, 1);
d6b4a7	238
G	239	msleep(29); /* datasheet: typ=22, max=29 */
	240	memset(buf, 0, sizeof(buf));
c5e9e8	241
G	242	i2c_read(sht2x, buf, 3);
d6b4a7	243	dump_buf("Relative humidity sample data: ", buf, 3);
c5e9e8	244	rh = 125 (((((int) buf[0]) << 8) + buf[1]) / 65536.0) - 6;
d6b4a7	245
G	246	return 0;
	247	}
	248
c5e9e8	249	int sht2x_get_serialnumber(sht2x_t sht2x, uint8_t serialnumber, int size)
d6b4a7	250	{
c5e9e8	251	uint8_t buf[4]={0x0};
d6b4a7	252
c5e9e8	253	if( !sht2x \|\| sht2x->fd<0 \|\| !serialnumber \|\| size!=8 )
d6b4a7	254	{
c5e9e8	255	printf("%s line [%d] %s() get invalid input arguments\n", __FILE__, __LINE__, __func__ );
G	256	return -1;
d6b4a7	257	}
G	258
c5e9e8	259	/* Read SerialNumber from Location 1 */
G	260	memset(buf, 0, sizeof(buf));
	261	buf[0] = 0xfa; /* command for readout on-chip memory */
	262	buf[1] = 0x0f; /* on-chip memory address */
	263	i2c_write(sht2x, buf, 2);
	264
	265	memset(buf, 0, sizeof(buf));
	266	i2c_read(sht2x, buf, 4);
	267
	268	if( !buf[0] && !buf[1] && !buf[2] && !buf[3] )
	269	{
	270	printf("ERROR: SHT2X device not detected!\n");
	271	return -2;
	272	}
	273
	274	serialnumber[5]=buf[0]; /* Read SNB_3 */
	275	serialnumber[4]=buf[1]; /* Read SNB_2 */
	276	serialnumber[3]=buf[2]; /* Read SNB_1 */
	277	serialnumber[2]=buf[3]; /* Read SNB_0 */
	278
	279	/* Read SerialNumber from Location 2 */
	280	memset(buf, 0, sizeof(buf) );
	281	buf[0]=0xfc; /* command for readout on-chip memory */
	282	buf[1]=0xc9; /* on-chip memory address */
	283	i2c_write(sht2x, buf, 2);
	284
	285	memset(buf, 0, sizeof(buf) );
	286	i2c_read(sht2x, buf, 4);
	287
	288	serialnumber[1]=buf[0]; /* Read SNC_1 */
	289	serialnumber[0]=buf[1]; /* Read SNC_0 */
	290	serialnumber[7]=buf[2]; /* Read SNA_1 */
	291	serialnumber[6]=buf[3]; /* Read SNA_0 */
	292
	293	dump_buf("SHT2x Serial number: ", serialnumber, 8);
	294
	295	return 0;
d6b4a7	296	}
G	297
c5e9e8	298	static int i2c_write(sht2x_t sht2x, uint8_t data, int len)
d6b4a7	299	{
c5e9e8	300	struct i2c_rdwr_ioctl_data i2cdata;
G	301	int rv = 0;
d6b4a7	302
G	303	if( !data \|\| len<= 0)
	304	{
	305	printf("%s() invalid input arguments!\n", __func__);
	306	return -1;
	307	}
	308
c5e9e8	309	/* I2C device program API: read()/write() */
G	310	if( MODE_RDWR == sht2x->mode )
	311	{
	312	write(sht2x->fd, data, len);
	313	return 0;
	314	}
	315
	316	/* I2C device program API: ioctl() */
d6b4a7	317	i2cdata.nmsgs = 1;
G	318	i2cdata.msgs = malloc( sizeof(struct i2c_msg)*i2cdata.nmsgs );
	319	if ( !i2cdata.msgs )
	320	{
	321	printf("%s() msgs malloc failed!\n", __func__);
	322	return -2;
	323	}
	324
c5e9e8	325	i2cdata.msgs[0].addr = sht2x->addr;
d6b4a7	326	i2cdata.msgs[0].flags = 0; //write
G	327	i2cdata.msgs[0].len = len;
	328	i2cdata.msgs[0].buf = malloc(len);
	329	if( !i2cdata.msgs[0].buf )
	330	{
	331	printf("%s() msgs malloc failed!\n", __func__);
	332	rv = -3;
	333	goto cleanup;
	334	}
	335	memcpy(i2cdata.msgs[0].buf, data, len);
	336
	337
c5e9e8	338	if( ioctl(sht2x->fd, I2C_RDWR, &i2cdata)<0 )
d6b4a7	339	{
G	340	printf("%s() ioctl failure: %s\n", __func__, strerror(errno));
	341	rv = -4;
	342	goto cleanup;
	343	}
	344
	345	cleanup:
	346	if( i2cdata.msgs[0].buf )
	347	free(i2cdata.msgs[0].buf);
	348
	349	if( i2cdata.msgs )
	350	free(i2cdata.msgs);
	351
	352	return rv;
	353	}
	354
c5e9e8	355	static int i2c_read(sht2x_t sht2x, uint8_t buf, int size)
d6b4a7	356	{
c5e9e8	357	struct i2c_rdwr_ioctl_data i2cdata;
G	358	int rv = 0;
d6b4a7	359
G	360	if( !buf \|\| size<= 0)
	361	{
	362	printf("%s() invalid input arguments!\n", __func__);
	363	return -1;
	364	}
	365
c5e9e8	366	/* I2C device program API: read()/write() */
G	367	if( MODE_RDWR == sht2x->mode )
	368	{
	369	read(sht2x->fd, buf, size);
	370	return 0;
	371	}
	372
	373	/* I2C device program API: ioctl() */
d6b4a7	374	i2cdata.nmsgs = 1;
G	375	i2cdata.msgs = malloc( sizeof(struct i2c_msg)*i2cdata.nmsgs );
	376	if ( !i2cdata.msgs )
	377	{
	378	printf("%s() msgs malloc failed!\n", __func__);
	379	return -2;
	380	}
	381
c5e9e8	382	i2cdata.msgs[0].addr = sht2x->addr;
d6b4a7	383	i2cdata.msgs[0].flags = I2C_M_RD; //read
G	384	i2cdata.msgs[0].len = size;
	385	i2cdata.msgs[0].buf = buf;
	386	memset(buf, 0, size);
	387
c5e9e8	388	if( ioctl(sht2x->fd, I2C_RDWR, &i2cdata)<0 )
d6b4a7	389	{
G	390	printf("%s() ioctl failure: %s\n", __func__, strerror(errno));
	391	rv = -4;
	392	}
	393
	394	free( i2cdata.msgs );
	395	return rv;
	396	}
c5e9e8	397
G	398	/*+----------------+
	399	*\| Misc functions \|
	400	+----------------+/
d6b4a7	401
G	402	static inline void msleep(unsigned long ms)
	403	{
	404	struct timespec cSleep;
	405	unsigned long ulTmp;
	406
	407	cSleep.tv_sec = ms / 1000;
	408	if (cSleep.tv_sec == 0)
	409	{
	410	ulTmp = ms * 10000;
	411	cSleep.tv_nsec = ulTmp * 100;
	412	}
	413	else
	414	{
	415	cSleep.tv_nsec = 0;
	416	}
	417
	418	nanosleep(&cSleep, 0);
	419	}
	420
	421	static inline void dump_buf(const char prompt, uint8_t buf, int size)
	422	{
	423	int i;
	424
	425	if( !buf )
	426	{
	427	return ;
	428	}
	429
	430	if( prompt )
	431	{
c5e9e8	432	printf("%s ", prompt);
d6b4a7	433	}
G	434
	435	for(i=0; i<size; i++)
	436	{
	437	printf("%02x ", buf[i]);
	438	}
	439	printf("\n");
	440
	441	return ;
	442	}