Added library code to read DHT11 temperature/humidity sensor

Thu, 08 May 2014 22:36:51 +0200

author
Michiel Broek <mbroek@mbse.eu>
date
Thu, 08 May 2014 22:36:51 +0200
changeset 31
89dd2b691701
parent 30
9c7119ac0455
child 32
3bac8fd4173d

Added library code to read DHT11 temperature/humidity sensor

.hgignore file | annotate | diff | comparison | revisions
configure file | annotate | diff | comparison | revisions
configure.ac file | annotate | diff | comparison | revisions
dht11/Makefile file | annotate | diff | comparison | revisions
dht11/dht11.c file | annotate | diff | comparison | revisions
dht11/dht11.h file | annotate | diff | comparison | revisions
lib/Makefile file | annotate | diff | comparison | revisions
lib/dht11.c file | annotate | diff | comparison | revisions
lib/mbselib.h file | annotate | diff | comparison | revisions
--- a/.hgignore	Thu May 08 15:09:56 2014 +0200
+++ b/.hgignore	Thu May 08 22:36:51 2014 +0200
@@ -10,6 +10,7 @@
 rc433/send
 rc433/sniffer
 coolers/coolers
+dht11/dht11
 
 syntax: glob
 *.o
--- a/configure	Thu May 08 15:09:56 2014 +0200
+++ b/configure	Thu May 08 22:36:51 2014 +0200
@@ -2028,11 +2028,11 @@
 
 ac_config_headers="$ac_config_headers config.h"
 
-SUBDIRS="lib coolers rc433 thermometers"
+SUBDIRS="lib coolers dht11 rc433 thermometers"
 
 
 PACKAGE="mbsePi-apps"
-VERSION="0.0.4"
+VERSION="0.0.5"
 COPYRIGHT="Copyright (C) 2014 Michiel Broek, All Rights Reserved"
 CYEARS="2014"
 
--- a/configure.ac	Thu May 08 15:09:56 2014 +0200
+++ b/configure.ac	Thu May 08 22:36:51 2014 +0200
@@ -2,13 +2,13 @@
 
 AC_INIT(thermometers/main.c)
 AM_CONFIG_HEADER(config.h)
-SUBDIRS="lib coolers rc433 thermometers"
+SUBDIRS="lib coolers dht11 rc433 thermometers"
 AC_SUBST(SUBDIRS)
 
 dnl General settings
 dnl After changeing the version number, run autoconf!
 PACKAGE="mbsePi-apps"
-VERSION="0.0.4"
+VERSION="0.0.5"
 COPYRIGHT="Copyright (C) 2014 Michiel Broek, All Rights Reserved"
 CYEARS="2014"
 AC_SUBST(PACKAGE)
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dht11/Makefile	Thu May 08 22:36:51 2014 +0200
@@ -0,0 +1,58 @@
+# Makefile for the mbsePi-apps/thermometers.
+
+include ../Makefile.global
+
+SRCS		= dht11.c
+HDRS		= dht11.h
+OBJS		= dht11.o
+SLIBS		= ../lib/libmbse.a
+TARGET		= dht11
+OTHER		= Makefile
+
+#############################################################################
+
+.c.o:
+		${CC} ${CFLAGS} ${INCLUDES} ${DEFINES} -c $<
+
+all:		${TARGET}
+
+dht11:		dht11.o ${SLIBS}
+		${CC} -o dht11 dht11.o ${LDFLAGS} ${LIBS} ${SLIBS}
+
+clean:
+		rm -f ${TARGET} *.o *.h~ *.c~ core filelist Makefile.bak
+
+install:	all
+		${INSTALL} -c -s -g root -o root -m 0755 ${TARGET} ${BINDIR}
+
+filelist:	Makefile
+		BASE=`pwd`; \
+		BASE=`basename $${BASE}`; \
+		(for f in ${SRCS} ${HDRS} ${OTHER} ;do echo ${PACKAGE}-${VERSION}/$${BASE}/$$f; done) >filelist
+
+depend:
+	@rm -f Makefile.bak; \
+	mv Makefile Makefile.bak; \
+	sed -e '/^# DO NOT DELETE/,$$d' Makefile.bak >Makefile; \
+	${ECHO} '# DO NOT DELETE THIS LINE - MAKE DEPEND RELIES ON IT' \
+		>>Makefile; \
+	${ECHO} '# Dependencies generated by make depend' >>Makefile; \
+	for f in ${SRCS}; \
+	do \
+		${ECHO} "Dependencies for $$f:\c"; \
+		${ECHO} "`basename $$f .c`.o:\c" >>Makefile; \
+		for h in `sed -n -e \
+			's/^#[ 	]*include[ 	]*"\([^"]*\)".*/\1/p' $$f`; \
+		do \
+			${ECHO} " $$h\c"; \
+			${ECHO} " $$h\c" >>Makefile; \
+		done; \
+		${ECHO} " done."; \
+		${ECHO} "" >>Makefile; \
+	done; \
+	${ECHO} '# End of generated dependencies' >>Makefile
+
+# DO NOT DELETE THIS LINE - MAKE DEPEND RELIES ON IT
+# Dependencies generated by make depend
+dht11.o: ../lib/mbselib.h dht11.h
+# End of generated dependencies
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dht11/dht11.c	Thu May 08 22:36:51 2014 +0200
@@ -0,0 +1,58 @@
+/*****************************************************************************
+ * Copyright (C) 2014
+ *   
+ * Michiel Broek <mbroek at mbse dot eu>
+ *
+ * This file is part of the mbsePi-apps
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * mbsePi-apps is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with EC-65K; see the file COPYING.  If not, write to the Free
+ * Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *****************************************************************************/
+
+#include "../lib/mbselib.h"
+#include "dht11.h"
+
+#ifdef HAVE_WIRINGPI_H
+
+extern int	dht11_valid;
+extern int	dht11_temperature;
+extern int	dht11_humidity;
+
+int main(int argc, char *argv[]) {
+  
+    int PIN = 3;
+     
+    if (wiringPiSetup() == -1)
+	return 0;
+
+    dht11Init(PIN, 0, 6);
+    dht11Read();
+    if (dht11_valid) {
+	fprintf(stdout, "DHT11: temperature %d degrees, humidity %d%%\n", dht11_temperature, dht11_humidity);
+    } else {
+	fprintf(stdout, "DHT11: no valid data or sensor not connected\n");
+    }
+
+    exit(0);
+}
+
+#else
+
+int main(int argc, char *argv[]) {
+    fprintf(stderr, "This program does nothing without the wiringPi library\n");
+    return 0;
+}
+
+#endif
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dht11/dht11.h	Thu May 08 22:36:51 2014 +0200
@@ -0,0 +1,9 @@
+#ifndef	_DHT11_H
+#define	_DHT11_H
+
+
+#define TRUE 1
+#define FALSE 0
+
+
+#endif
--- a/lib/Makefile	Thu May 08 15:09:56 2014 +0200
+++ b/lib/Makefile	Thu May 08 22:36:51 2014 +0200
@@ -2,8 +2,8 @@
 
 include ../Makefile.global
 
-SRCS		= xutil.c rdconfig.c lcd-pcf8574.c rc-switch.c
-OBJS		= xutil.o rdconfig.o lcd-pcf8574.o rc-switch.o
+SRCS		= xutil.c rdconfig.c lcd-pcf8574.c rc-switch.c dht11.c
+OBJS		= xutil.o rdconfig.o lcd-pcf8574.o rc-switch.o dht11.o
 HDRS		= mbselib.h
 TARGET		= libmbse.a
 
@@ -48,4 +48,5 @@
 rdconfig.o: ../config.h mbselib.h
 lcd-pcf8574.o: ../config.h mbselib.h
 rc-switch.o: ../config.h mbselib.h
+dht11.o: ../config.h mbselib.h
 # End of generated dependencies
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/dht11.c	Thu May 08 22:36:51 2014 +0200
@@ -0,0 +1,167 @@
+/*****************************************************************************
+ * Copyright (C) 2008-2014
+ *   
+ * Michiel Broek <mbroek at mbse dot eu>
+ *
+ * This file is part of the mbsePi-apps
+ *
+ * Parts original by CurlyMo from the pilight project.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * mbsePi-apps is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with EC-65K; see the file COPYING.  If not, write to the Free
+ * Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *****************************************************************************/
+
+#include "../config.h"
+#include "mbselib.h"
+
+#ifdef HAVE_WIRINGPI_H
+
+#define MAXTIMINGS 100
+
+int		dht11_pin = -1;
+int		dht11_temperature = -1;
+int		dht11_humidity = -1;
+int		dht11_valid = false;
+int		dht11_t_offset = 0;
+int		dht11_h_offset = 0;
+
+
+
+static uint8_t sizecvt(const int read_value) {
+    /* 
+     * digitalRead() and friends from wiringpi are defined as returning a value
+     *            < 256. However, they are returned as int() types. This is a safety function 
+     */
+    if (read_value > 255 || read_value < 0) {
+	syslog(LOG_NOTICE, "invalid data from wiringPi library");
+    }
+		  
+    return (uint8_t)read_value;
+}
+
+
+
+/*
+ * DHT11 sensor read. This should be used in a thread loop.
+ */
+void dht11Read(void) {
+    int         	tries = 5;
+    unsigned short	got_correct_data = 0;
+
+    if (dht11_pin == -1)
+	return;
+
+    while (tries && !got_correct_data) {
+	uint8_t	laststate = HIGH;
+	uint8_t	counter = 0;
+	uint8_t	j = 0, i = 0;
+	int	dht11_dat[5] = {0,0,0,0,0};
+
+	/*
+	 * Select output mode to send the start signal.
+	 */
+	pinMode(dht11_pin, OUTPUT);                 
+	digitalWrite(dht11_pin, HIGH);
+	usleep(1000);
+
+	/*
+	 * Low for at least 18 milliseconds
+	 */
+	digitalWrite(dht11_pin, LOW);
+	usleep(20000);
+	digitalWrite(dht11_pin, HIGH);
+	pinMode(dht11_pin, INPUT);
+
+	/*
+	 * Detect change and read data
+	 */
+	for (i=0; i<MAXTIMINGS; i++) {
+	    counter = 0;
+	    delayMicroseconds(10);
+	    while (sizecvt(digitalRead(dht11_pin)) == laststate) {
+		counter++;
+		delayMicroseconds(1);
+		if (counter == 255) {
+		    break;
+		}
+	    }
+	    laststate = sizecvt(digitalRead(dht11_pin));
+
+	    if (counter == 255) 
+		break;
+
+	    /*
+	     * ignore first 3 transitions
+	     */
+	    if ((i >= 4) && (i%2 == 0)) {
+
+		// shove each bit into the storage bytes
+		dht11_dat[(int)((double)j/8)] <<= 1;
+		if (counter > 16)
+		    dht11_dat[(int)((double)j/8)] |= 1;
+		j++;
+	    }
+	}
+
+	/*
+	 * If there is no sensor, j = 0
+	 */
+	if ((counter == 255) && (j == 0)) {
+	    if (dht11_temperature != -1) {
+		syslog(LOG_NOTICE, "dht11 sensor disappeared");
+	    }
+	    dht11_temperature = -1;
+	    dht11_humidity = -1;
+	    dht11_valid = false;
+	} else {
+
+	    /*
+	     * check we read 40 bits (8bit x 5 ) + verify checksum in the last byte
+	     * print it out if data is good
+	     */
+	    if ((j >= 40) && (dht11_dat[4] == ((dht11_dat[0] + dht11_dat[1] + dht11_dat[2] + dht11_dat[3]) & 0xFF))) {
+		got_correct_data = 1;
+
+		int h = dht11_dat[0] + dht11_dat[1];
+		int t = (dht11_dat[2] & 0x7F) + dht11_dat[3];
+		t += dht11_t_offset;
+		h += dht11_h_offset;
+
+		if ((dht11_dat[2] & 0x80) != 0) 
+		    t *= -1;
+
+		dht11_temperature = t;
+		dht11_humidity = h;
+		dht11_valid = true;
+	    } else {
+		tries--;
+		if (tries == 0)
+		    syslog(LOG_INFO, "dht11 data checksum was wrong 5 times");
+		usleep(100000);
+	    }
+	}
+    }
+}
+
+
+
+void dht11Init(int pin, int t_offset, int h_offset) {
+    dht11_pin = pin;
+    dht11_t_offset = t_offset;
+    dht11_h_offset = h_offset;
+}
+
+
+#endif
+
--- a/lib/mbselib.h	Thu May 08 15:09:56 2014 +0200
+++ b/lib/mbselib.h	Thu May 08 22:36:51 2014 +0200
@@ -128,6 +128,12 @@
 
 char *dec2binWzerofill(unsigned long, unsigned int);
 
+
+/* dht11.c */
+void dht11Read(void);
+void dht11Init(int, int, int);
+
+
 #endif
 
 

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