Revision 0:cd9dd4f2c484, committed 2014-09-09

Comitter:

mederic

Date:

Tue Sep 09 08:17:42 2014 +0000

Child:

1:aa96d283eead

Commit message:

first release

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MAX31855.cpp	Tue Sep 09 08:17:42 2014 +0000
@@ -0,0 +1,74 @@
+#include "MAX31855.h"
+
+//***********************************/************************************
+//                         Constructors                                 //
+//***********************************/************************************
+MAX31855::MAX31855(PinName mosi, PinName miso, PinName sck, PinName ncs) :_spi(mosi,miso,sck), _ncs(ncs)
+{
+    _ncs = 1;   //CS high
+    _spi.format(16,0);
+    _spi.frequency(1000000);
+}
+
+//***********************************/************************************
+//                                Get Set                               //
+//***********************************/************************************
+bool MAX31855::opened(void)
+{
+    read();
+    return _oc;
+}
+
+bool MAX31855::fault(void)
+{
+    read();
+    return _fault;
+}
+
+bool MAX31855::scToVcc(void)
+{
+    read();
+    return _scv;
+}
+
+bool MAX31855::scToGnd(void)
+{
+    read();
+    return _scg;
+}
+
+
+
+//***********************************/************************************
+//                             Public Methods                           //
+//***********************************/************************************
+float MAX31855::thermocouple(void)
+{
+    read();
+    return _t;
+}
+
+float MAX31855::chip(void)
+{
+    read();
+    return _chip_t;
+}
+    
+//***********************************/************************************
+//                             Protected Methods                        //
+//***********************************/************************************
+void MAX31855::read(void)
+{
+    _ncs = 0;
+    unsigned short high = _spi.write(0);
+    unsigned short  low = _spi.write(0);
+    _ncs = 1;
+    
+    _t = (high>>2)/4.0;
+    _chip_t = (low>>4)/16.0;
+    _fault = high&0x01;
+    _scv = low&0x04;
+    _scg = low&0x02;
+    _oc = low&0x01;
+    
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MAX31855.h	Tue Sep 09 08:17:42 2014 +0000
@@ -0,0 +1,93 @@
+#ifndef MAX31855_H
+#define MAX31855_H
+
+#include "mbed.h"
+/** MAX31855 class.
+ *  Used for read MAX31855 Cold-Junction Compensated Thermocouple-to-Digital Converter
+ *
+ * Example:
+ * @code
+ * DigitalOut led(LED2);
+ * Serial pc(USBTX,USBRX);
+ * MAX31855 therm(p5,p6,p7,p8);
+ * 
+ * int main() 
+ * {
+ *     while(1) 
+ *     {
+ *         pc.printf("T=%f;Chip=%f\r\n",therm.thermocouple(),therm.chip());
+ *         led  = therm.fault();
+ *         wait(0.5);
+ *     }
+ * }
+ * @endcode
+ */  
+class MAX31855
+{
+public:
+    /** Create MAX31855 instance connected to spi & ncs
+    * @param mosi SPI master out slave in pin (MAX31855 is only read device)
+    * @param miso SPI master in slave out pin
+    * @param sck SPI clock pin
+    * @param ncs pin to connect at CS input
+    */
+    MAX31855(PinName mosi, PinName miso, PinName sck, PinName ncs);
+    
+    /**Get Thermocouple temperature
+    * @returns temperature [°C]
+    */    
+    float thermocouple(void);
+    
+    /**Get Chip temperature
+    * @returns temperature [°C]
+    */       
+    float chip(void);
+    
+    /**Check if thermocouple disconnected
+    */
+    bool opened(void);
+    
+    /**Check if an error
+    */
+    bool fault(void);
+    
+    /**Check if thermocouple short-circuited to Vcc
+    */
+    bool scToVcc(void);
+    
+    /**Check if thermocouple shorted-circuited to GND
+    */
+    bool scToGnd(void);
+
+#ifdef MBED_OPERATORS
+    /** An operator shorthand for thermocouple()
+     *
+     * The float() operator can be used as a shorthand for thermocouple() to simplify common code sequences
+     *
+     * Example:
+     * @code
+     * float x = temp.thermocouple();
+     * float x = temp;
+     *
+     * if(temp.thermocouple() > 20.25) { ... }
+     * if(temp > 20.25) { ... }
+     * @endcode
+     */
+    operator float(){return thermocouple();}
+#endif
+    
+protected:
+    void read(void);
+      
+private:
+    SPI         _spi;
+    DigitalOut  _ncs;
+    float       _t;
+    float       _chip_t;
+    bool        _fault;
+    bool        _scv;
+    bool        _scg;
+    bool        _oc;
+};
+
+#endif
\ No newline at end of file