Amit Gandhi / DHT22

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

Fork of DHT11 by Eric Fossum

Dht11.h@1:5da6f6de3e42, 2015-02-16 (annotated)

Committer:
fossum_13
Date:
Mon Feb 16 01:43:08 2015 +0000
Revision:
1:5da6f6de3e42
Parent:
0:c1da310d3e8a 
Added documentation and some minor improvements. Not backwards compatible!

Who changed what in which revision?

UserRevisionLine numberNew contents of line
fossum_13 0:c1da310d3e8a 1 #ifndef DHT11_H
fossum_13 0:c1da310d3e8a 2 #define DHT11_H
fossum_13 0:c1da310d3e8a 3
fossum_13 0:c1da310d3e8a 4 #include "mbed.h"
fossum_13 0:c1da310d3e8a 5
fossum_13 0:c1da310d3e8a 6 #define DHTLIB_OK 0
fossum_13 0:c1da310d3e8a 7 #define DHTLIB_ERROR_CHECKSUM -1
fossum_13 0:c1da310d3e8a 8 #define DHTLIB_ERROR_TIMEOUT -2
fossum_13 0:c1da310d3e8a 9
fossum_13 1:5da6f6de3e42 10 /** Class for the DHT11 sensor.
fossum_13 1:5da6f6de3e42 11 *
fossum_13 1:5da6f6de3e42 12 * Example:
fossum_13 1:5da6f6de3e42 13 * @code
fossum_13 1:5da6f6de3e42 14 * #include "mbed.h"
fossum_13 1:5da6f6de3e42 15 * #include "Dht11.h"
fossum_13 1:5da6f6de3e42 16 *
fossum_13 1:5da6f6de3e42 17 * Serial pc(USBTX, USBRX);
fossum_13 1:5da6f6de3e42 18 * Dht11 sensor(PTD7);
fossum_13 1:5da6f6de3e42 19 *
fossum_13 1:5da6f6de3e42 20 * int main() {
fossum_13 1:5da6f6de3e42 21 * sensor.read()
fossum_13 1:5da6f6de3e42 22 * pc.printf("T: %f, H: %d\r\n", sensor.getFahrenheit(), sensor.getHumidity());
fossum_13 1:5da6f6de3e42 23 * }
fossum_13 1:5da6f6de3e42 24 * @endcode
fossum_13 1:5da6f6de3e42 25 */
fossum_13 1:5da6f6de3e42 26 class Dht11
fossum_13 1:5da6f6de3e42 27 {
fossum_13 0:c1da310d3e8a 28 public:
fossum_13 1:5da6f6de3e42 29 /** Construct the sensor object.
fossum_13 1:5da6f6de3e42 30 *
fossum_13 1:5da6f6de3e42 31 * @param pin PinName for the sensor pin.
fossum_13 1:5da6f6de3e42 32 */
fossum_13 1:5da6f6de3e42 33 Dht11(PinName const &p);
fossum_13 1:5da6f6de3e42 34
fossum_13 1:5da6f6de3e42 35 /** Update the humidity and temp from the sensor.
fossum_13 1:5da6f6de3e42 36 *
fossum_13 1:5da6f6de3e42 37 * @returns
fossum_13 1:5da6f6de3e42 38 * 0 on success, otherwise error.
fossum_13 1:5da6f6de3e42 39 */
fossum_13 0:c1da310d3e8a 40 int read();
fossum_13 1:5da6f6de3e42 41
fossum_13 1:5da6f6de3e42 42 /** Get the temp(f) from the saved object.
fossum_13 1:5da6f6de3e42 43 *
fossum_13 1:5da6f6de3e42 44 * @returns
fossum_13 1:5da6f6de3e42 45 * Fahrenheit float
fossum_13 1:5da6f6de3e42 46 */
fossum_13 1:5da6f6de3e42 47 float getFahrenheit();
fossum_13 0:c1da310d3e8a 48
fossum_13 1:5da6f6de3e42 49 /** Get the temp(c) from the saved object.
fossum_13 1:5da6f6de3e42 50 *
fossum_13 1:5da6f6de3e42 51 * @returns
fossum_13 1:5da6f6de3e42 52 * Celsius int
fossum_13 1:5da6f6de3e42 53 */
fossum_13 1:5da6f6de3e42 54 int getCelsius();
fossum_13 1:5da6f6de3e42 55
fossum_13 1:5da6f6de3e42 56 /** Get the humidity from the saved object.
fossum_13 1:5da6f6de3e42 57 *
fossum_13 1:5da6f6de3e42 58 * @returns
fossum_13 1:5da6f6de3e42 59 * Humidity percent int
fossum_13 1:5da6f6de3e42 60 */
fossum_13 1:5da6f6de3e42 61 int getHumidity();
fossum_13 1:5da6f6de3e42 62
fossum_13 0:c1da310d3e8a 63 private:
fossum_13 1:5da6f6de3e42 64 /// percentage of humidity
fossum_13 0:c1da310d3e8a 65 int _humidity;
fossum_13 1:5da6f6de3e42 66 /// celsius
fossum_13 0:c1da310d3e8a 67 int _temperature;
fossum_13 1:5da6f6de3e42 68 /// pin to read the sensor info on
fossum_13 0:c1da310d3e8a 69 DigitalInOut _pin;
fossum_13 1:5da6f6de3e42 70 /// times startup (must settle for at least a second)
fossum_13 0:c1da310d3e8a 71 Timer _timer;
fossum_13 0:c1da310d3e8a 72 };
fossum_13 0:c1da310d3e8a 73
fossum_13 0:c1da310d3e8a 74 #endif