Алексей Лебедев / DHT11

Simple library for the DHT11 temperature and humidity sensor. Forked from an existing Mbed DHT11 project.

DHT11.h@13:11d0770eb603, 2021-09-15 (annotated)

Committer:
ajp109
Date:
Wed Sep 15 14:47:06 2021 +0000
Revision:
13:11d0770eb603
Parent:
12:af1eadec17e5 
Interface changes to remove the need for separate readData() calls

Who changed what in which revision?

UserRevisionLine numberNew contents of line
s_inoue_mbed 10:f0d789f49df7 1 /* Copyright (c) 2014 Shigenori Inoue, MIT License
s_inoue_mbed 10:f0d789f49df7 2 *
s_inoue_mbed 10:f0d789f49df7 3 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
s_inoue_mbed 10:f0d789f49df7 4 * and associated documentation files (the "Software"), to deal in the Software without restriction,
s_inoue_mbed 10:f0d789f49df7 5 * including without limitation the rights to use, copy, modify, merge, publish, distribute,
s_inoue_mbed 10:f0d789f49df7 6 * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
s_inoue_mbed 10:f0d789f49df7 7 * furnished to do so, subject to the following conditions:
s_inoue_mbed 10:f0d789f49df7 8 *
s_inoue_mbed 10:f0d789f49df7 9 * The above copyright notice and this permission notice shall be included in all copies or
s_inoue_mbed 10:f0d789f49df7 10 * substantial portions of the Software.
s_inoue_mbed 10:f0d789f49df7 11 *
s_inoue_mbed 10:f0d789f49df7 12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
s_inoue_mbed 10:f0d789f49df7 13 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
s_inoue_mbed 10:f0d789f49df7 14 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
s_inoue_mbed 10:f0d789f49df7 15 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
s_inoue_mbed 10:f0d789f49df7 16 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
s_inoue_mbed 0:4d4c5ea17d86 17 */
s_inoue_mbed 10:f0d789f49df7 18
s_inoue_mbed 0:4d4c5ea17d86 19 #ifndef __DHT11__
s_inoue_mbed 0:4d4c5ea17d86 20 #define __DHT11__
s_inoue_mbed 0:4d4c5ea17d86 21 #include "mbed.h"
s_inoue_mbed 0:4d4c5ea17d86 22
s_inoue_mbed 0:4d4c5ea17d86 23 /** Example:
s_inoue_mbed 0:4d4c5ea17d86 24 * @code
s_inoue_mbed 0:4d4c5ea17d86 25 * #include "mbed.h"
s_inoue_mbed 0:4d4c5ea17d86 26 * #include "DHT11.h"
s_inoue_mbed 0:4d4c5ea17d86 27 *
JohnnyK 12:af1eadec17e5 28 * DHT11 d(D8); // Here fill your PIN mask/name
s_inoue_mbed 0:4d4c5ea17d86 29 *
s_inoue_mbed 0:4d4c5ea17d86 30 * main()
s_inoue_mbed 0:4d4c5ea17d86 31 * {
ajp109 13:11d0770eb603 32 * printf("T:%d, H:%d\r\n", d.readTemperature(), d.readHumidity());
s_inoue_mbed 0:4d4c5ea17d86 33 * }
s_inoue_mbed 0:4d4c5ea17d86 34 * @endcode
s_inoue_mbed 0:4d4c5ea17d86 35 */
s_inoue_mbed 0:4d4c5ea17d86 36
s_inoue_mbed 0:4d4c5ea17d86 37 class DHT11
s_inoue_mbed 9:056d1e9b428c 38 {
s_inoue_mbed 0:4d4c5ea17d86 39 public:
s_inoue_mbed 0:4d4c5ea17d86 40 /** Create a DHT11 interface
s_inoue_mbed 0:4d4c5ea17d86 41 * @param pin 1-wire-like serial I/O port of DHT11
s_inoue_mbed 0:4d4c5ea17d86 42 */
s_inoue_mbed 0:4d4c5ea17d86 43 DHT11(PinName pin);
s_inoue_mbed 0:4d4c5ea17d86 44 ~DHT11();
s_inoue_mbed 0:4d4c5ea17d86 45
ajp109 13:11d0770eb603 46 /** Reading the data from the DHT11. Calling this is not required, but
ajp109 13:11d0770eb603 47 * may be useful for debug.
s_inoue_mbed 0:4d4c5ea17d86 48 * @return Error code
s_inoue_mbed 0:4d4c5ea17d86 49 * 0: OK.
s_inoue_mbed 0:4d4c5ea17d86 50 * 1: Reading the data too often.
s_inoue_mbed 0:4d4c5ea17d86 51 * 2: 1-wire bus is busy.
s_inoue_mbed 0:4d4c5ea17d86 52 * 3: DHT11 does not respond.
s_inoue_mbed 0:4d4c5ea17d86 53 * 4: DHT11 is not ready.
s_inoue_mbed 0:4d4c5ea17d86 54 * 5: Checksum is incorrect.
s_inoue_mbed 5:da586c935e88 55 * 6: Timeout.
s_inoue_mbed 0:4d4c5ea17d86 56 */
s_inoue_mbed 3:8cd064147bde 57 int readData(void);
s_inoue_mbed 3:8cd064147bde 58
ajp109 13:11d0770eb603 59 /** Returns the current humidity from the DHT11. If the existing data record
ajp109 13:11d0770eb603 60 * is older than 2000ms, initiates a read from the device. Note that errors
ajp109 13:11d0770eb603 61 * may result in infinite attempts to read.
ajp109 13:11d0770eb603 62 * @return Humidity in %
s_inoue_mbed 0:4d4c5ea17d86 63 */
s_inoue_mbed 0:4d4c5ea17d86 64 int readHumidity(void);
s_inoue_mbed 3:8cd064147bde 65
ajp109 13:11d0770eb603 66 /** Returns the current temperature from the DHT11. If the existing data record
ajp109 13:11d0770eb603 67 * is older than 2000ms, initiates a read from the device. Note that errors
ajp109 13:11d0770eb603 68 * may result in infinite attempts to read.
ajp109 13:11d0770eb603 69 * @return Temperature in Celcius
s_inoue_mbed 0:4d4c5ea17d86 70 */
s_inoue_mbed 0:4d4c5ea17d86 71 int readTemperature(void);
s_inoue_mbed 3:8cd064147bde 72
s_inoue_mbed 0:4d4c5ea17d86 73 enum ErrorDHT11 {
s_inoue_mbed 0:4d4c5ea17d86 74 OK = 0,
s_inoue_mbed 9:056d1e9b428c 75 READ_TOO_OFTEN = 1,
s_inoue_mbed 0:4d4c5ea17d86 76 BUS_BUSY = 2,
s_inoue_mbed 0:4d4c5ea17d86 77 NOT_PRESENT = 3,
s_inoue_mbed 0:4d4c5ea17d86 78 NOT_READY = 4,
s_inoue_mbed 0:4d4c5ea17d86 79 CHKSUM_ERR = 5,
s_inoue_mbed 0:4d4c5ea17d86 80 WATCHDOG_ERR = 6,
s_inoue_mbed 0:4d4c5ea17d86 81 };
s_inoue_mbed 0:4d4c5ea17d86 82
s_inoue_mbed 0:4d4c5ea17d86 83 private:
s_inoue_mbed 0:4d4c5ea17d86 84 DigitalInOut io;
s_inoue_mbed 0:4d4c5ea17d86 85 InterruptIn io_irq;
s_inoue_mbed 0:4d4c5ea17d86 86 Timer t;
s_inoue_mbed 0:4d4c5ea17d86 87 uint32_t t_pulse_us;
s_inoue_mbed 9:056d1e9b428c 88 const static int t_tol_start;
s_inoue_mbed 9:056d1e9b428c 89 const static int t_tol_pulse;
s_inoue_mbed 0:4d4c5ea17d86 90 uint64_t data;
s_inoue_mbed 0:4d4c5ea17d86 91 uint32_t chksum;
s_inoue_mbed 0:4d4c5ea17d86 92 uint32_t cnt;
s_inoue_mbed 0:4d4c5ea17d86 93 uint32_t wdt;
s_inoue_mbed 0:4d4c5ea17d86 94 bool eod;
s_inoue_mbed 0:4d4c5ea17d86 95 void init(void);
s_inoue_mbed 0:4d4c5ea17d86 96 void pos_edge(void);
s_inoue_mbed 0:4d4c5ea17d86 97 void neg_edge(void);
ajp109 13:11d0770eb603 98 void readNewData(void);
s_inoue_mbed 0:4d4c5ea17d86 99 };
s_inoue_mbed 0:4d4c5ea17d86 100
s_inoue_mbed 0:4d4c5ea17d86 101 #endif