DS18B20Sensor.h

00001 #ifndef _SENSOR_H
00002 #define _SENSOR_H
00003 
00004 #include "mbed.h"
00005 #include "DS18X20.h"
00006 #include "onewire.h"
00007  
00008 /** DS18B20Sensor class.
00009  *  A wrapper class for the DS18B20 (temperature sensor) and onewire 'c' library.
00010  *  Based on the OneWireDrv Library by Frederic Blanc. Many thanks to him for making this code available.
00011  *  
00012  * Simple Example:
00013  * @code
00014 #include "mbed.h"
00015 #include "DS18B20Sensor.h"
00016 
00017 // Instantiate sensor with hardware in pin p30 
00018 DS18B20Sensor sensor(p30);
00019 
00020 // Setup a window to the world
00021 Serial pc(p13, p14);
00022 //Serial pc(USBTX, USBRX);
00023  
00024 int main()
00025 {
00026    char sensorBuf[25];
00027  
00028    // count will search for sensors, if not already called
00029    pc.printf("Found %d sensor/s\r", sensor.count());
00030  
00031    uint8_t result = sensor.startReading(true);     // start sensor readings and wait
00032  
00033    for (uint8_t i = 0; i < sensor.count(); i++) {
00034       sensor.getReading(sensorBuf, i);         // get result into buf
00035       pc.printf("Sensor %d : %s\r", i+1, sensorBuf);  // display it to the world
00036    }
00037  
00038 }
00039  * @endcode
00040  */
00041 class DS18B20Sensor
00042 {
00043 public:
00044     /** Create DS18B20Sensor instance
00045     * @param pin The pin number used by the onewire bus.
00046     */
00047     DS18B20Sensor(PinName pin);
00048 
00049     /** Copies the sensor results into the parameter text.
00050     * @param text The target text buffer.
00051     * @param index The sensor number.
00052     */
00053     void getReading(char * text, uint8_t index);
00054 
00055     /** Copies the sensor results into the parameter text.
00056     * @param text The target text buffer.
00057     * @param subzero 1 for less than zero.
00058     * @param cel Degrees Cel
00059     * @param cel Degrees fraction
00060     */
00061     void getReading(char * text, uint8_t subzero, uint8_t cel, uint8_t cel_frac_bits);
00062 
00063     /** Gets the sensors reading results.
00064     * @param index The sensor number.
00065     * @param subzero Returns 1 if less than zero.
00066     * @param cel Returns degrees Cel
00067     * @param cel Returns degrees fraction
00068     */
00069     void getReading(uint8_t index, uint8_t *subzero, uint8_t *cel, uint8_t *cel_frac_bits);
00070 
00071     /** This searches for sensors on the onewire bus.
00072     *   It can also invoked by just using count()
00073     *   @returns The number of sensors found on the bus.
00074     */
00075     uint8_t search(void);
00076 
00077     /** Starts the sensors reading.
00078     * @param includeWait If true, the method will wait the specified time for the sensors to complete the reading.
00079     * @returns
00080         DS18X20_OK on success,
00081         Other values in DS18X20.h on failure.
00082     */
00083     uint8_t startReading(bool includeWait = true);
00084 
00085     /** If search() was not called before this, then search() is invoked.
00086     *   @returns The number of sensors found on the bus.
00087     */
00088     uint8_t count(void);
00089 
00090 protected:
00091 
00092     DigitalInOut _oneWirePort;
00093     uint8_t gSensorIDs[MAXSENSORS][OW_ROMCODE_SIZE];
00094     uint8_t nSensors;
00095     bool _init;
00096 
00097 };
00098 
00099 #endif // file