Hotboards_temp.h

00001 /*
00002   Hotboards_temp.h - Driver to read and control a serial (i2c) temperature sensor, The Microchip
00003   MCP9808 is the digital sensor to control, can be read it, set its resolution, shutdown and also
00004   set alarms.
00005   Hotboards eeprom board (http://hotboards.org)
00006   Created by Diego Perez, March 19, 2016.
00007   Released into the public domain.
00008 */
00009 #ifndef Hotboards_Temp_h
00010 #define Hotboards_Temp_h
00011 
00012 #include "mbed.h"
00013 
00014 #define HT_SENSOR_OFF   0
00015 #define HT_SENSOR_ON    1
00016 
00017 typedef enum
00018 {
00019     Sensor_0 = 0,
00020     Sensor_1,
00021     Sensor_2,
00022     Sensor_3,
00023     Sensor_4,
00024     Sensor_5,
00025     Sensor_6,
00026     Sensor_7
00027 } _eSensors;
00028 
00029 typedef enum
00030 {
00031     _0p5C = 0,
00032     _0p25C,
00033     _0p125C,
00034     _0p0625C
00035 } _eResolution;
00036 
00037 /** Hotboards_temp class.
00038  *  Used to read and config Microchip MCP9808 i2c temp sensor
00039  *
00040  * Example:
00041  * @code
00042  * #include "Hotboards_temp.h"
00043  *
00044  * Hotboards_temp sensor( Sensor_7 );
00045  *
00046  * int main( void )
00047  * {
00048  *   Wire.begin( );
00049  *   sensor.begin( );
00050  *   while(1){
00051  *     float val = sensor.read( );
00052  *     printf( "temp. %f", val );
00053  *     wait(1);
00054  *   }
00055  * }
00056  * @endcode
00057  */
00058 class Hotboards_temp
00059 {
00060     public :
00061     
00062         /** Create Hotboards_temp instance
00063           * @param i2c iic peripheral to use with the temp sensor
00064           * @param address sensor address (A0,A1 and A2 values)
00065           * @param resolution default temperature resoluion (use values from _eResolution enumeration)
00066           *
00067           * Example:
00068           * @code
00069           *   // instance temp sensor with address 7 and 0.5 resolution (default)
00070           *   Hotboards_temp sensor( Sensor_7 );
00071           * @endcode
00072           */
00073         Hotboards_temp( I2C &i2c, uint8_t address, uint8_t resolution = _0p5C );
00074 
00075         /** Detect if the sensor is conected and also set default resolution
00076           * @return '1' if a sensor is connected
00077           *
00078           * Example:
00079           * @code
00080           *   // init sensor and also check if is conected
00081           *   if( sensor.begin( ) == 1 ){
00082           *     // sensor is detected, do something
00083           *   }
00084           * @endcode
00085           */
00086         bool init( void );
00087 
00088         /** Get temperature from sensor in Celsius degrees
00089           * @return The current temperature
00090           *
00091           * Example:
00092           * @code
00093           *   // init temp sensor (assume sensor is connected)
00094           *   sensor.begin( );
00095           *   // read the current temperaure
00096           *   float temp = sensor.read( );
00097           * @endcode
00098           */
00099         float read( void );
00100         /** Set Tlower and Tupper values and also active ALERT output pin
00101           * @param lower lower temperaure value to set ALERT pin
00102           * @param upper upper temperaure value to set ALERT pin
00103           *
00104           * Example:
00105           * @code
00106           *   // set lower nd upper alarm (on setup function)
00107           *   sensor.setAlarm( 0.0, 10.0 );
00108           *   // somewhere else on loop function
00109           *   // assume we conected pin 5 (arduino) to ALERT pin (sensor)
00110           *   if( readDigital(5) == 0 ){
00111           *     // temp value under lower valur or upper value
00112           *   }
00113           * @endcode
00114           */
00115         void setAlarms( float lower, float upper );
00116 
00117         /** Disable alarma activation, the function does not clear the previus
00118           * alarm values, just disable the ALERT signal
00119           *
00120           * Example:
00121           * @code
00122           *   // set lower nd upper alarm (on setup function)
00123           *   sensor.setAlarm( 0.0, 10.0 );
00124           *   // disable alarm, ALERt signal is disable
00125           *   sensor.disableAlarms( );
00126           * @endcode
00127           */
00128         void disableAlarms( void );
00129 
00130         /** Turn Off/On sensor (low power), after turn it on again, is necesary wait
00131           * from 30ms to 250ms (depends on resoluion) to read a valid temperature
00132           * @param state shutdown (HT_SENSOR_OFF) or turn on (HT_SENSOR_ON)
00133           *
00134           * Example:
00135           * @code
00136           *   // lets assume sensor is initialized, so shutdown
00137           *   sensor.shutdown( HT_SENSOR_OFF );
00138           *   // the we can turn it on
00139           *   sensor.shutdown( HT_SENSOR_ON );
00140           * @endcode
00141           */
00142         void shutdown( bool state );
00143 
00144         /** set a new resolution, possible values are 0.0625, 0.125, 0.25 and 0.5
00145           * @param resolution use values from _eResolution enumeration (_0p5C, _0p25C, _0p125C and _0p0625C)
00146           *
00147           * Example:
00148           * @code
00149           *   // lets assume sensor is initialized
00150           *   sensor.setResolution( _0p0625C );
00151           *   // read temperature with the new resolution
00152           *   float temp = sensor.read( );
00153           * @endcode
00154           */
00155         void setResolution( uint8_t resolution );
00156 
00157         /** Function to convert Celsius to Farenheit degrees
00158           * @param celsius temperature in celsius degrees
00159           *
00160           * Example:
00161           * @code
00162           *   // read temperature in celsius degrees
00163           *   float tempC = sensor.read( );
00164           *   // convert to farenheit
00165           *   float tempF = sensor.CelsiusToFarenheit( tempC );
00166           * @endcode
00167           */
00168         float CelsiusToFarenheit( float celsius );
00169 
00170         /** Function to convert Farenheit to Celsius degrees
00171           * @param farenheit temperature in farenheit degrees
00172           *
00173           * Example:
00174           * @code
00175           *   // convert to celsius a previus farenheit temperature
00176           *   float tempC = sensor.FarenheitToCelsius( 98.5 );
00177           * @endcode
00178           */
00179         float FarenheitToCelsius( float farenheit );
00180 
00181     private :
00182         uint16_t readReg( uint8_t reg );
00183         void writeReg( uint8_t reg, uint16_t val );
00184         void writeAlarm( uint16_t reg, float temp );
00185         I2C _i2c;
00186         uint8_t _address;
00187         uint8_t _resolution;
00188 };
00189 
00190 #endif