From c5e9e88eb8c6039cd2a4d2b3fdae0b1e3d8aea40 Mon Sep 17 00:00:00 2001
From: guowenxue <guowenxue@gmail.com>
Date: Tue, 12 Mar 2024 17:19:23 +0800
Subject: [PATCH] Update sht20 source code, add both ioctl and read/write API support
---
modules/sht20.c | 291 ++++++++++++++++++++++++++++++++++++++++------------------
1 files changed, 201 insertions(+), 90 deletions(-)
diff --git a/modules/sht20.c b/modules/sht20.c
index d84877f..c3aa745 100644
--- a/modules/sht20.c
+++ b/modules/sht20.c
@@ -20,7 +20,6 @@
* dtoverlay=i2c1,pins_2_3
*
********************************************************************************/
-
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -39,11 +38,37 @@
#include <linux/i2c.h>
#include <linux/i2c-dev.h>
-int i2c_write(int fd, uint8_t slave_addr, uint8_t *data, int len);
-int i2c_read(int fd, uint8_t slave_addr, uint8_t *buf, int size);
-int sht20_checksum(uint8_t *data, int len, int8_t checksum);
+/* SHT2X 7-bit I2C slave address */
+#define SHT2X_CHIPADDR 0x40
+
+/* SHT2X trigger command */
+#define SOFTRESET 0xFE
+#define TRIGGER_TEMPERATURE_NO_HOLD 0xF3
+#define TRIGGER_HUMIDITY_NO_HOLD 0xF5
+
+/* Linux /dev/i2c-x device program API mode */
+enum
+{
+ MODE_IOCTL, /* I2C device API use ioctl() */
+ MODE_RDWR, /* I2C device API use read()/write() */
+};
+
+typedef struct sht2x_s
+{
+ char *dev; /* SHT20 connect I2C device, /dev/i2c-N */
+ int addr; /* SHT20 7-bits slave address */
+ int fd; /* File description */
+ int mode; /* I2C device API use read/write or ioctl mode */
+} sht2x_t;
+
+int sht2x_init(sht2x_t *sht2x);
+int sht2x_get_serialnumber(sht2x_t *sht2x, uint8_t *serialnumber, int size);
+int sht2x_get_temp_humidity(sht2x_t *sht2x, float *temp, float *rh);
+
static inline void msleep(unsigned long ms);
static inline void dump_buf(const char *prompt, uint8_t *buf, int size);
+static int i2c_write(sht2x_t *sht2x, uint8_t *data, int len);
+static int i2c_read(sht2x_t *sht2x, uint8_t *buf, int size);
static inline void banner(const char *progname)
{
@@ -58,6 +83,7 @@
printf(" %s is SHT20 temperature and humidity sensor program. \n", progname);
printf(" -d[device ] Specify I2C device, such as /dev/i2c-1\n");
+ printf(" -m[mode ] Specify API mode, 0 for ioctl and 1 for read()/write()\n");
printf(" -h[help ] Display this help information\n");
printf(" -v[version ] Display the program version\n");
@@ -68,14 +94,15 @@
int main(int argc, char **argv)
{
- int fd, rv;
+ int rv;
float temp, rh;
- char *dev = "/dev/i2c-1";
- char *progname=NULL;
- uint8_t buf[4];
+ uint8_t serialnumber[8];
+ char *progname=NULL;
+ sht2x_t sht2x;
struct option long_options[] = {
{"device", required_argument, NULL, 'd'},
+ {"mode", required_argument, NULL, 'm'},
{"version", no_argument, NULL, 'v'},
{"help", no_argument, NULL, 'h'},
{NULL, 0, NULL, 0}
@@ -83,13 +110,21 @@
progname = basename(argv[0]);
+ memset(&sht2x, 0, sizeof(sht2x));
+ sht2x.addr = SHT2X_CHIPADDR;
+ sht2x.dev = "/dev/i2c-1";
+
/* Parser the command line parameters */
- while ((rv = getopt_long(argc, argv, "d:vh", long_options, NULL)) != -1)
+ while ((rv = getopt_long(argc, argv, "d:m:vh", long_options, NULL)) != -1)
{
switch (rv)
{
case 'd': /* Set I2C device path: /dev/i2c-1 */
- dev = optarg;
+ sht2x.dev = optarg;
+ break;
+
+ case 'm': /* Set I2C API mode: 0,1 */
+ sht2x.mode = atoi(optarg) ? MODE_RDWR : MODE_IOCTL;
break;
case 'v': /* Get software version */
@@ -105,108 +140,165 @@
}
}
-
- /*+--------------------------------+
- *| open /dev/i2c-x device |
- *+--------------------------------+*/
- if( (fd=open(dev, O_RDWR)) < 0)
+ if( sht2x_init(&sht2x) < 0 )
{
- printf("i2c device '%s' open failed: %s\n", dev, strerror(errno));
+ printf("SHT2x initialize failure, maybe device not present!\n");
+ return 1;
+ }
+
+ if( sht2x_get_serialnumber(&sht2x, serialnumber, 8) < 0)
+ {
+ printf("SHT2x get serial number failure\n");
+ return 3;
+ }
+
+ if( sht2x_get_temp_humidity(&sht2x, &temp, &rh) < 0 )
+ {
+ printf("SHT2x get get temperature and relative humidity failure\n");
+ return 3;
+ }
+
+ printf("Temperature=%lf ℃ relative humidity=%lf.\n", temp, rh);
+
+ close(sht2x.fd);
+}
+
+int sht2x_softreset(sht2x_t *sht2x)
+{
+ uint8_t buf[1];
+
+ if( !sht2x || sht2x->fd<0 )
+ {
+ printf("%s line [%d] %s() get invalid input arguments\n", __FILE__, __LINE__, __func__ );
return -1;
}
- /*+--------------------------------+
- *| software reset SHT20 sensor |
- *+--------------------------------+*/
-
- buf[0] = 0xFE;
- i2c_write(fd, 0x40, buf, 1);
+ /* software reset SHT2x */
+ buf[0] = SOFTRESET;
+ if( i2c_write(sht2x, buf, 1) < 0 )
+ {
+ return -2;
+ }
msleep(50);
+ return 0;
+}
- /*+--------------------------------+
- *| trigger temperature measure |
- *+--------------------------------+*/
+int sht2x_init(sht2x_t *sht2x)
+{
+ if( (sht2x->fd=open(sht2x->dev, O_RDWR)) < 0)
+ {
+ printf("i2c device open failed: %s\n", strerror(errno));
+ return -1;
+ }
- buf[0] = 0xF3;
- i2c_write(fd, 0x40, buf, 1);
+ if( MODE_RDWR == sht2x->mode )
+ {
+ /* set I2C mode and SHT2x slave address */
+ ioctl(sht2x->fd, I2C_TENBIT, 0); /* Not 10-bit but 7-bit mode */
+ ioctl(sht2x->fd, I2C_SLAVE, SHT2X_CHIPADDR); /* set SHT2x slave address 0x40*/
+ }
+
+ if( sht2x_softreset(sht2x) < 0 )
+ {
+ printf("SHT2x softreset failure\n");
+ return -2;
+ }
+
+ return 0;
+}
+
+int sht2x_get_temp_humidity(sht2x_t *sht2x, float *temp, float *rh)
+{
+ uint8_t buf[4];
+
+ if( !sht2x || !temp || !rh || sht2x->fd<0 )
+ {
+ printf("%s line [%d] %s() get invalid input arguments\n", __FILE__, __LINE__, __func__ );
+ return -1;
+ }
+
+ /* send trigger temperature measure command and read the data */
+ memset(buf, 0, sizeof(buf));
+ buf[0]=TRIGGER_TEMPERATURE_NO_HOLD;
+ i2c_write(sht2x, buf, 1);
msleep(85); /* datasheet: typ=66, max=85 */
memset(buf, 0, sizeof(buf));
- i2c_read(fd, 0x40, buf, 3);
+ i2c_read(sht2x, buf, 3);
dump_buf("Temperature sample data: ", buf, 3);
+ *temp = 175.72 * (((((int) buf[0]) << 8) + buf[1]) / 65536.0) - 46.85;
- if( !sht20_checksum(buf, 2, buf[2]) )
- {
- printf("Temperature sample data CRC checksum failure.\n");
- goto cleanup;
- }
-
- temp = 175.72 * (((((int) buf[0]) << 8) + buf[1]) / 65536.0) - 46.85;
-
-
- /*+--------------------------------+
- *| trigger humidity measure |
- *+--------------------------------+*/
-
- buf[0] = 0xF5;
- i2c_write(fd, 0x40, buf, 1);
+ /* send trigger humidity measure command and read the data */
+ memset(buf, 0, sizeof(buf));
+ buf[0] = TRIGGER_HUMIDITY_NO_HOLD;
+ i2c_write(sht2x, buf, 1);
msleep(29); /* datasheet: typ=22, max=29 */
-
memset(buf, 0, sizeof(buf));
- i2c_read(fd, 0x40, buf, 3);
+
+ i2c_read(sht2x, buf, 3);
dump_buf("Relative humidity sample data: ", buf, 3);
+ *rh = 125 * (((((int) buf[0]) << 8) + buf[1]) / 65536.0) - 6;
- if( !sht20_checksum(buf, 2, buf[2]) )
- {
- printf("Relative humidity sample data CRC checksum failure.\n");
- goto cleanup;
- }
-
- rh = 125 * (((((int) buf[0]) << 8) + buf[1]) / 65536.0) - 6;
-
- /*+--------------------------------+
- *| print the measure result |
- *+--------------------------------+*/
-
- printf("Temperature=%lf 'C relative humidity=%lf%%\n", temp, rh);
-
-cleanup:
- close(fd);
return 0;
}
-int sht20_checksum(uint8_t *data, int len, int8_t checksum)
+int sht2x_get_serialnumber(sht2x_t *sht2x, uint8_t *serialnumber, int size)
{
- int8_t crc = 0;
- int8_t bit;
- int8_t byteCtr;
+ uint8_t buf[4]={0x0};
- //calculates 8-Bit checksum with given polynomial: x^8 + x^5 + x^4 + 1
- for (byteCtr = 0; byteCtr < len; ++byteCtr)
+ if( !sht2x || sht2x->fd<0 || !serialnumber || size!=8 )
{
- crc ^= (data[byteCtr]);
- for ( bit = 8; bit > 0; --bit)
- {
- /* x^8 + x^5 + x^4 + 1 = 0001 0011 0001 = 0x131 */
- if (crc & 0x80) crc = (crc << 1) ^ 0x131;
- else crc = (crc << 1);
- }
+ printf("%s line [%d] %s() get invalid input arguments\n", __FILE__, __LINE__, __func__ );
+ return -1;
}
- if (crc != checksum)
- return 0;
- else
- return 1;
+ /* Read SerialNumber from Location 1 */
+ memset(buf, 0, sizeof(buf));
+ buf[0] = 0xfa; /* command for readout on-chip memory */
+ buf[1] = 0x0f; /* on-chip memory address */
+ i2c_write(sht2x, buf, 2);
+
+ memset(buf, 0, sizeof(buf));
+ i2c_read(sht2x, buf, 4);
+
+ if( !buf[0] && !buf[1] && !buf[2] && !buf[3] )
+ {
+ printf("ERROR: SHT2X device not detected!\n");
+ return -2;
+ }
+
+ serialnumber[5]=buf[0]; /* Read SNB_3 */
+ serialnumber[4]=buf[1]; /* Read SNB_2 */
+ serialnumber[3]=buf[2]; /* Read SNB_1 */
+ serialnumber[2]=buf[3]; /* Read SNB_0 */
+
+ /* Read SerialNumber from Location 2 */
+ memset(buf, 0, sizeof(buf) );
+ buf[0]=0xfc; /* command for readout on-chip memory */
+ buf[1]=0xc9; /* on-chip memory address */
+ i2c_write(sht2x, buf, 2);
+
+ memset(buf, 0, sizeof(buf) );
+ i2c_read(sht2x, buf, 4);
+
+ serialnumber[1]=buf[0]; /* Read SNC_1 */
+ serialnumber[0]=buf[1]; /* Read SNC_0 */
+ serialnumber[7]=buf[2]; /* Read SNA_1 */
+ serialnumber[6]=buf[3]; /* Read SNA_0 */
+
+ dump_buf("SHT2x Serial number: ", serialnumber, 8);
+
+ return 0;
}
-int i2c_write(int fd, uint8_t slave_addr, uint8_t *data, int len)
+static int i2c_write(sht2x_t *sht2x, uint8_t *data, int len)
{
- struct i2c_rdwr_ioctl_data i2cdata;
- int rv = 0;
+ struct i2c_rdwr_ioctl_data i2cdata;
+ int rv = 0;
if( !data || len<= 0)
{
@@ -214,6 +306,14 @@
return -1;
}
+ /* I2C device program API: read()/write() */
+ if( MODE_RDWR == sht2x->mode )
+ {
+ write(sht2x->fd, data, len);
+ return 0;
+ }
+
+ /* I2C device program API: ioctl() */
i2cdata.nmsgs = 1;
i2cdata.msgs = malloc( sizeof(struct i2c_msg)*i2cdata.nmsgs );
if ( !i2cdata.msgs )
@@ -222,7 +322,7 @@
return -2;
}
- i2cdata.msgs[0].addr = slave_addr;
+ i2cdata.msgs[0].addr = sht2x->addr;
i2cdata.msgs[0].flags = 0; //write
i2cdata.msgs[0].len = len;
i2cdata.msgs[0].buf = malloc(len);
@@ -235,7 +335,7 @@
memcpy(i2cdata.msgs[0].buf, data, len);
- if( ioctl(fd, I2C_RDWR, &i2cdata)<0 )
+ if( ioctl(sht2x->fd, I2C_RDWR, &i2cdata)<0 )
{
printf("%s() ioctl failure: %s\n", __func__, strerror(errno));
rv = -4;
@@ -252,10 +352,10 @@
return rv;
}
-int i2c_read(int fd, uint8_t slave_addr, uint8_t *buf, int size)
+static int i2c_read(sht2x_t *sht2x, uint8_t *buf, int size)
{
- struct i2c_rdwr_ioctl_data i2cdata;
- int rv = 0;
+ struct i2c_rdwr_ioctl_data i2cdata;
+ int rv = 0;
if( !buf || size<= 0)
{
@@ -263,6 +363,14 @@
return -1;
}
+ /* I2C device program API: read()/write() */
+ if( MODE_RDWR == sht2x->mode )
+ {
+ read(sht2x->fd, buf, size);
+ return 0;
+ }
+
+ /* I2C device program API: ioctl() */
i2cdata.nmsgs = 1;
i2cdata.msgs = malloc( sizeof(struct i2c_msg)*i2cdata.nmsgs );
if ( !i2cdata.msgs )
@@ -271,13 +379,13 @@
return -2;
}
- i2cdata.msgs[0].addr = slave_addr;
+ i2cdata.msgs[0].addr = sht2x->addr;
i2cdata.msgs[0].flags = I2C_M_RD; //read
i2cdata.msgs[0].len = size;
i2cdata.msgs[0].buf = buf;
memset(buf, 0, size);
- if( ioctl(fd, I2C_RDWR, &i2cdata)<0 )
+ if( ioctl(sht2x->fd, I2C_RDWR, &i2cdata)<0 )
{
printf("%s() ioctl failure: %s\n", __func__, strerror(errno));
rv = -4;
@@ -286,6 +394,10 @@
free( i2cdata.msgs );
return rv;
}
+
+/*+----------------+
+ *| Misc functions |
+ *+----------------+*/
static inline void msleep(unsigned long ms)
{
@@ -304,7 +416,6 @@
}
nanosleep(&cSleep, 0);
- return ;
}
static inline void dump_buf(const char *prompt, uint8_t *buf, int size)
@@ -318,7 +429,7 @@
if( prompt )
{
- printf("%-32s ", prompt);
+ printf("%s ", prompt);
}
for(i=0; i<size; i++)
--
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