Diff: SHT40.h

Revision:

0:c46b3e0a8c2b

Child:

1:c6381a3f2d9a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SHT40.h	Mon Feb 07 15:08:07 2022 +0000
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+/*!
+ *  @file Adafruit_SHT4x.cpp
+ *
+ *  @mainpage Adafruit SHT4x Digital Humidity & Temp Sensor
+ *
+ *  @section intro_sec Introduction
+ *
+ *  This is a library for the SHT4x Digital Humidity & Temp Sensor
+ *
+ *  Designed specifically to work with the SHT4x Digital sensor from Adafruit
+ *
+ *  Pick one up today in the adafruit shop!
+ *  ------> https://www.adafruit.com/product/4885
+ *
+ *  These sensors use I2C to communicate, 2 pins are required to interface
+ *
+ *  Adafruit invests time and resources providing this open source code,
+ *  please support Adafruit andopen-source hardware by purchasing products
+ *  from Adafruit!
+ *
+ *  @section author Author
+ *
+ *  Limor Fried/Ladyada (Adafruit Industries).
+ *
+ *  @section license License
+ *
+ *  BSD license, all text above must be included in any redistribution
+ * 
+ * @reworked by Andrew Reed areed@cityplym.ac.uk
+ * 
+ * simple driver hacked together by hardware engineer, definite scope for 
+ * improvement by someone who knows what they are doing.
+ *
+ * @section DESCRIPTION
+ *
+ * SHT40 i2c Humidity and Temperature sensor.
+ *
+ */
+
+#ifndef SHT40_H
+#define SHT40_H
+
+/**
+ * Includes
+ */
+#include "mbed.h"
+
+/**
+ * Defines
+ */
+// Acquired from adafruit arduino SHT4x.h
+
+#define SHT40_I2C_ADDRESS           0x44
+#define SHT4x_NOHEAT_HIGHPRECISION  0xFD 
+#define SHT4x_NOHEAT_MEDPRECISION   0xF6 
+#define SHT4x_NOHEAT_LOWPRECISION   0xE0 
+#define SHT4x_HIGHHEAT_1S           0x39 
+#define SHT4x_HIGHHEAT_100MS        0x32 
+#define SHT4x_MEDHEAT_1S            0x2F 
+#define SHT4x_MEDHEAT_100MS         0x24 
+#define SHT4x_LOWHEAT_1S            0x1E 
+#define SHT4x_LOWHEAT_100MS         0x15 
+#define SHT4x_READSERIAL            0x89 
+#define SHT4x_SOFTRESET             0x94  
+#define I2C_SPEED_STANDARD        100000
+#define I2C_SPEED_FAST            400000  
+
+/**
+ * 2 byte packet is sent to device as instruction
+ * 6 byte packet is received from device
+ * received data includes checksum in byte 3 for bytes 1 and 2
+ * and byte 6 for bytes 4 and 5.
+ */
+static uint8_t crc8(const uint8_t *data, int len); 
+ 
+/**
+ * Adafruit SHT40 i2c digital humidity and temperature sensor.
+ */
+class SHT40 {
+
+public:
+
+    /**
+     * Constructor.
+     *
+     * @param sda mbed pin to use for SDA line of I2C interface.
+     * @param scl mbed pin to use for SCL line of I2C interface.
+     */
+    SHT40(PinName sda, PinName scl);
+
+
+    //Reads the temperature, input void, outputs an int in celcius.
+    int tempC(void);
+      
+    //Reads the relative humidity, input void, outputs and int.
+    int relHumid(void);
+    
+    /* @ToDo populate a struct that returns temp and humidity in one call
+     * struct tempHumid{
+     *    int tempC; // or maybe a float?
+     *    int relHumid;
+     *  }
+     */  
+   
+
+private:
+
+    I2C* i2c_;
+
+};
+
+#endif /* SHT40_H */