Andrew Reed / SHT40

Adafruit SHT40 basic driver

Dependents:   SHT40-example

Basic library for Adafruit SHT40 Working on PSoC6 Pioneer dev board CY8CKIT-062-WIFI-BT

SHT40.h@1:c6381a3f2d9a, 2022-02-14 (annotated)

Committer:
reedas
Date:
Mon Feb 14 23:53:34 2022 +0000
Revision:
1:c6381a3f2d9a
Parent:
0:c46b3e0a8c2b 
added floating point return values;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
reedas 0:c46b3e0a8c2b 1 /*!
reedas 0:c46b3e0a8c2b 2 * @file Adafruit_SHT4x.cpp
reedas 0:c46b3e0a8c2b 3 *
reedas 0:c46b3e0a8c2b 4 * @mainpage Adafruit SHT4x Digital Humidity & Temp Sensor
reedas 0:c46b3e0a8c2b 5 *
reedas 0:c46b3e0a8c2b 6 * @section intro_sec Introduction
reedas 0:c46b3e0a8c2b 7 *
reedas 0:c46b3e0a8c2b 8 * This is a library for the SHT4x Digital Humidity & Temp Sensor
reedas 0:c46b3e0a8c2b 9 *
reedas 0:c46b3e0a8c2b 10 * Designed specifically to work with the SHT4x Digital sensor from Adafruit
reedas 0:c46b3e0a8c2b 11 *
reedas 0:c46b3e0a8c2b 12 * Pick one up today in the adafruit shop!
reedas 0:c46b3e0a8c2b 13 * ------> https://www.adafruit.com/product/4885
reedas 0:c46b3e0a8c2b 14 *
reedas 0:c46b3e0a8c2b 15 * These sensors use I2C to communicate, 2 pins are required to interface
reedas 0:c46b3e0a8c2b 16 *
reedas 0:c46b3e0a8c2b 17 * Adafruit invests time and resources providing this open source code,
reedas 0:c46b3e0a8c2b 18 * please support Adafruit andopen-source hardware by purchasing products
reedas 0:c46b3e0a8c2b 19 * from Adafruit!
reedas 0:c46b3e0a8c2b 20 *
reedas 0:c46b3e0a8c2b 21 * @section author Author
reedas 0:c46b3e0a8c2b 22 *
reedas 0:c46b3e0a8c2b 23 * Limor Fried/Ladyada (Adafruit Industries).
reedas 0:c46b3e0a8c2b 24 *
reedas 0:c46b3e0a8c2b 25 * @section license License
reedas 0:c46b3e0a8c2b 26 *
reedas 0:c46b3e0a8c2b 27 * BSD license, all text above must be included in any redistribution
reedas 0:c46b3e0a8c2b 28 *
reedas 0:c46b3e0a8c2b 29 * @reworked by Andrew Reed areed@cityplym.ac.uk
reedas 0:c46b3e0a8c2b 30 *
reedas 0:c46b3e0a8c2b 31 * simple driver hacked together by hardware engineer, definite scope for
reedas 0:c46b3e0a8c2b 32 * improvement by someone who knows what they are doing.
reedas 0:c46b3e0a8c2b 33 *
reedas 0:c46b3e0a8c2b 34 * @section DESCRIPTION
reedas 0:c46b3e0a8c2b 35 *
reedas 0:c46b3e0a8c2b 36 * SHT40 i2c Humidity and Temperature sensor.
reedas 0:c46b3e0a8c2b 37 *
reedas 0:c46b3e0a8c2b 38 */
reedas 0:c46b3e0a8c2b 39
reedas 0:c46b3e0a8c2b 40 #ifndef SHT40_H
reedas 0:c46b3e0a8c2b 41 #define SHT40_H
reedas 0:c46b3e0a8c2b 42
reedas 0:c46b3e0a8c2b 43 /**
reedas 0:c46b3e0a8c2b 44 * Includes
reedas 0:c46b3e0a8c2b 45 */
reedas 0:c46b3e0a8c2b 46 #include "mbed.h"
reedas 0:c46b3e0a8c2b 47
reedas 0:c46b3e0a8c2b 48 /**
reedas 0:c46b3e0a8c2b 49 * Defines
reedas 0:c46b3e0a8c2b 50 */
reedas 0:c46b3e0a8c2b 51 // Acquired from adafruit arduino SHT4x.h
reedas 0:c46b3e0a8c2b 52
reedas 0:c46b3e0a8c2b 53 #define SHT40_I2C_ADDRESS 0x44
reedas 0:c46b3e0a8c2b 54 #define SHT4x_NOHEAT_HIGHPRECISION 0xFD
reedas 0:c46b3e0a8c2b 55 #define SHT4x_NOHEAT_MEDPRECISION 0xF6
reedas 0:c46b3e0a8c2b 56 #define SHT4x_NOHEAT_LOWPRECISION 0xE0
reedas 0:c46b3e0a8c2b 57 #define SHT4x_HIGHHEAT_1S 0x39
reedas 0:c46b3e0a8c2b 58 #define SHT4x_HIGHHEAT_100MS 0x32
reedas 0:c46b3e0a8c2b 59 #define SHT4x_MEDHEAT_1S 0x2F
reedas 0:c46b3e0a8c2b 60 #define SHT4x_MEDHEAT_100MS 0x24
reedas 0:c46b3e0a8c2b 61 #define SHT4x_LOWHEAT_1S 0x1E
reedas 0:c46b3e0a8c2b 62 #define SHT4x_LOWHEAT_100MS 0x15
reedas 0:c46b3e0a8c2b 63 #define SHT4x_READSERIAL 0x89
reedas 0:c46b3e0a8c2b 64 #define SHT4x_SOFTRESET 0x94
reedas 0:c46b3e0a8c2b 65 #define I2C_SPEED_STANDARD 100000
reedas 0:c46b3e0a8c2b 66 #define I2C_SPEED_FAST 400000
reedas 0:c46b3e0a8c2b 67
reedas 0:c46b3e0a8c2b 68 /**
reedas 0:c46b3e0a8c2b 69 * 2 byte packet is sent to device as instruction
reedas 0:c46b3e0a8c2b 70 * 6 byte packet is received from device
reedas 0:c46b3e0a8c2b 71 * received data includes checksum in byte 3 for bytes 1 and 2
reedas 0:c46b3e0a8c2b 72 * and byte 6 for bytes 4 and 5.
reedas 0:c46b3e0a8c2b 73 */
reedas 0:c46b3e0a8c2b 74 static uint8_t crc8(const uint8_t *data, int len);
reedas 0:c46b3e0a8c2b 75
reedas 0:c46b3e0a8c2b 76 /**
reedas 0:c46b3e0a8c2b 77 * Adafruit SHT40 i2c digital humidity and temperature sensor.
reedas 0:c46b3e0a8c2b 78 */
reedas 0:c46b3e0a8c2b 79 class SHT40 {
reedas 0:c46b3e0a8c2b 80
reedas 0:c46b3e0a8c2b 81 public:
reedas 0:c46b3e0a8c2b 82
reedas 0:c46b3e0a8c2b 83 /**
reedas 0:c46b3e0a8c2b 84 * Constructor.
reedas 0:c46b3e0a8c2b 85 *
reedas 0:c46b3e0a8c2b 86 * @param sda mbed pin to use for SDA line of I2C interface.
reedas 0:c46b3e0a8c2b 87 * @param scl mbed pin to use for SCL line of I2C interface.
reedas 0:c46b3e0a8c2b 88 */
reedas 0:c46b3e0a8c2b 89 SHT40(PinName sda, PinName scl);
reedas 0:c46b3e0a8c2b 90
reedas 0:c46b3e0a8c2b 91
reedas 0:c46b3e0a8c2b 92 //Reads the temperature, input void, outputs an int in celcius.
reedas 0:c46b3e0a8c2b 93 int tempC(void);
reedas 0:c46b3e0a8c2b 94
reedas 0:c46b3e0a8c2b 95 //Reads the relative humidity, input void, outputs and int.
reedas 0:c46b3e0a8c2b 96 int relHumid(void);
reedas 1:c6381a3f2d9a 97 //Reads the temperature, input void, outputs an int in celcius.
reedas 1:c6381a3f2d9a 98 float tempCF(void);
reedas 1:c6381a3f2d9a 99
reedas 1:c6381a3f2d9a 100 //Reads the relative humidity, input void, outputs and int.
reedas 1:c6381a3f2d9a 101 float relHumidF(void);
reedas 0:c46b3e0a8c2b 102
reedas 0:c46b3e0a8c2b 103 /* @ToDo populate a struct that returns temp and humidity in one call
reedas 0:c46b3e0a8c2b 104 * struct tempHumid{
reedas 0:c46b3e0a8c2b 105 * int tempC; // or maybe a float?
reedas 0:c46b3e0a8c2b 106 * int relHumid;
reedas 0:c46b3e0a8c2b 107 * }
reedas 0:c46b3e0a8c2b 108 */
reedas 0:c46b3e0a8c2b 109
reedas 0:c46b3e0a8c2b 110
reedas 0:c46b3e0a8c2b 111 private:
reedas 0:c46b3e0a8c2b 112
reedas 0:c46b3e0a8c2b 113 I2C* i2c_;
reedas 0:c46b3e0a8c2b 114
reedas 0:c46b3e0a8c2b 115 };
reedas 0:c46b3e0a8c2b 116
reedas 0:c46b3e0a8c2b 117 #endif /* SHT40_H */