dht11-sensor.c File Reference

DHT 11 sensor implementation. More...

#include "contiki.h"
#include "dht11-sensor.h"
#include <string.h>
#include "dev/gpio-hal.h"

Go to the source code of this file.

Macros
#define	DHT11_SIGNAL_HIGH   (1)
	GPIO High.
#define	DHT11_SIGNAL_LOW   (0)
	GPIO Low.
#define	DHT11_SIGNAL_START_PHASE1_DURATION   (40)
	Duration of signal start phase 1 according to data sheet.
#define	DHT11_SIGNAL_START_PHASE2_DURATION   (80)
	Duration of signal start phase 2 according to data sheet.
#define	DHT11_SIGNAL_START_PHASE3_DURATION   (80)
	Duration of signal start phase 3 according to data sheet.
#define	DHT11_SIGNAL_RESPONSE_PHASE1_DURATION   (50)
	Duration of signal response phase 1 according to data sheet.
#define	DHT11_SIGNAL_RESPONSE_BIT_0_DURATION   (28)
	Duration of signal response if bit is set to 0, according to data sheet.
#define	DHT11_SIGNAL_RESPONSE_BIT_1_DURATION   (70)
	Duration of signal response if bit is set to 1, according to data sheet.
#define	DHT11_TICKS_GUARD   (1)
	Sensor timer drift in ticks.
#define	DHT11_US_GUARD   RTIMERTICKS_TO_US(1)
	Sensor timer drift in us from rtimer.
#define	DHT11_DATA_SAMPLES   (40)
	Number of data requests.
#define	DHT11_DATA_SIZE   (5)
	Number of bytes in data.
#define	DHT11_SAMPLING_RATE_SECONDS   (1)
	DHT11 maximum sample rate is 1 Hz (1 second)

Functions
static uint8_t	dht_read (void)

Variables
static dht_t	dht
	DHT struct.

Detailed Description

DHT 11 sensor implementation.

See also

https://www.mouser.com/datasheet/2/758/DHT11-Technical-Data-Sheet-Translated-Version-1143054.pdf

Author

Yago Fontoura do Rosario <yago..nosp@m.rosa.nosp@m.rio@h.nosp@m.otma.nosp@m.il.co.nosp@m.m.br

Definition in file dht11-sensor.c.