Simplified access to a Microchip Digital Potentiometer (MCP41xxx/MCP42xxx) devices

Dependents:   MCP41xxxApp MCP320xApp MCP41xxxApp

Revision:
6:ded0d8a6729c
Parent:
5:4f6133144e7e
Child:
7:12a0d89aa72f
--- a/MCP4xxxx_SPI.h	Fri Apr 05 13:36:29 2013 +0000
+++ b/MCP4xxxx_SPI.h	Thu Jun 06 07:59:16 2013 +0000
@@ -26,13 +26,19 @@
 
 namespace MCP4xxxx_SPI {
 
-    /** This class provides simplified SPI access to a Microchip MCP42xxx/MCP41xxx Digital Potentiometer device. V0.0.0.1
+    /** This class provides simplified SPI access to a Microchip MCP42xxx/MCP41xxx Digital Potentiometer device. V0.0.0.2
+     * The SPI static settings are: 16bits, mode (0,0)
+     * This class manages ONLY ONE /CS pin. If more than one SPI devices are used, ALL /CS pins shall be done by the application itself
      *
      * Microchip MCP42xxx/MCP41xxx Serial EEPROM device reference: DS11195C
+     * Microchip MCP41xx/MCP42xx Serial EEPROM device reference: DS122060B
      *
+     * Note that MCP41xxx has no SO pin, only a SOI input pin
+     * Note that MCP42xxx has a SO pin reserved for daisy-chain configuration
+     * Note that MCP41xx/MCP42xx increment/decrement operations are not supported due to the 16 bits SPI setting
      * Note that for SPI details, please visit http://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus
      *
-     * @remark This class was validated with Tektronix TDS2014 oscilloscope in 3.3V
+     * @remark This class was validated with Tektronix TDS2014 oscilloscope in 3.3V and in mixte power mode 3.3V for mbed and 5V for the Microchip 24LCxx Serial EEPROM device
      * @author Yann Garcia (Don't hesitate to contact me: garcia.yann@gmail.com)
      */
     class CMCP4xxxx_SPI { 
@@ -55,17 +61,37 @@
         /** An unique instance of SPI class
          */
         SPI *_spiInstance;
+        /** Increment step value used for inc/dec methods, when inc/dec commands are not supported (such as _4xxxx famillies)
+         */
+        unsigned char _incStep;
+     public:
+        /** MCP32xx familly
+         */
+        enum Mcp4xxxFamilly {
+            _41xxx = 0x00,  //<! 41xxx familly such as MCP41010 - See DS11195C
+            _42xxx = 0x01,  //<! 42xxx familly such as MCP42010 - See DS11195C
+            _41xx = 0x02,   //<! 41xx familly such as MCP4251 - Single Potentiometer/Rheostat
+            _42xx = 0x03    //<! 42x2 familly such as MCP42x2 - Dual Potentiometer/Rheostat
+       };
+        Mcp4xxxFamilly _familly;     
      public:
         /** Authorized commands
          * See DS11195C-page 18
          */
         enum Commands {
-            WriteToPot1, //<! Write to digital potentiometer #1
-            WriteToPot2, //<! Write to digital potentiometer #2
-            WriteToBoth, //<! Write to both digital potentiometers
-            ShutdownPot1, //<! Shutdown digital potentiometer #1
-            ShutdownPot2, //<! Shutdown digital potentiometer #2
-            ShutdownBoth, //<! Shutdown both digital potentiometers
+            WriteToDigiPot1,    //<! Write to digital potentiometer #1
+            WriteToDigiPot2,    //<! Write to digital potentiometer #2
+            WriteToBoth,        //<! Write to both digital potentiometers
+            ShutdownDigiPot1,   //<! Shutdown digital potentiometer #1
+            ShutdownDigiPot2,   //<! Shutdown digital potentiometer #2
+            ShutdownBoth,       //<! Shutdown both digital potentiometers
+        };
+        /** Register adresses
+         * See DS22060B-page 33 Clause 4.0 FUNCTIONAL OVERVIEW 
+         */
+        enum Addresses {
+            TCon = 0x04,
+            Status = 0x05
         };
    public:
         /** Constructor with Write Protect command pin wired.
@@ -78,10 +104,9 @@
          * @param p_shdn: MBed pin to manage /SHDN input. If NC, /SHDN is not managed, default value is NC, not connected
          * @param p_frequency: Frequency of the SPI interface (SCK), default value is 1MHz
          */
-        CMCP4xxxx_SPI(const PinName p_mosi, const PinName p_miso, const PinName p_sclk, const PinName p_cs = NC, const PinName p_reset = NC, const PinName p_shdn = NC, const unsigned int p_frequency = 1000000);
+        CMCP4xxxx_SPI(const PinName p_mosi, const PinName p_miso, const PinName p_sclk, const PinName p_cs = NC, const PinName p_reset = NC, const PinName p_shdn = NC, const Mcp4xxxFamilly familly = _41xxx, const unsigned int p_frequency = 1000000);
     
         /** Destructor
-         * /CS pin is set to 1 before to release it
          */
         virtual ~CMCP4xxxx_SPI();
 
@@ -89,9 +114,34 @@
          */
         inline const SPI * operator * () { return (const SPI *)_spiInstance; };
 
+        /** Write a value to the specified register. Only for _41xx/_42xx famillies
+         * @param p_address The register to be written
+         * @param p_value The value to write
+         * @return 0x0000 on success, any value otherwise
+         */
+        unsigned short WriteRegister(const Addresses p_address, const unsigned char p_value);
+        
+        /** Read the content of the specified register. Only for _41xx/_42xx famillies
+         * @param p_address The register to be written
+         * @return The register value 
+         */
+        unsigned short ReadRegister(const Addresses p_address);
+        
+        /** Increment the specified digital potentiometer
+         * @param p_command The digital potentiometer to increment. Default: WriteToDigiPot1
+         * @return 0x0000 on success, any value otherwise
+         */
+        unsigned short Incrememt(const Commands p_command = WriteToDigiPot1);
+        
+        /** Decrement the specified digital potentiometer
+         * @param p_command The digital potentiometer to decrement. Default: WriteToDigiPot1
+         * @return 0x0000 on success, any value otherwise
+         */
+        unsigned short Decrement(const Commands p_command = WriteToDigiPot1);
+
         /** Send a write a command (WriteToPot1, WriteToPot2 or WriteBoth)
          *
-         * @param p_command The command to execute: Write or Shutdown (See DS11195C-page 18)
+         * @param p_command The command to execute (See DS11195C-page 18)
          * @param p_value The potentiometer selection bits (See DS11195C-page 14 Clause 4.1 Modes of Operation)
          * @return 0x0000 on success, 0Xffff otherwise
          * Exemple:
@@ -108,42 +158,48 @@
     
         /** Send a shutdown a command (ShutdownPot1, ShutdownPot2 or ShutdownBoth)
          *
-         * @param p_command The command to execute: Write or Shutdown (See DS11195C-page 18)
-         * @param p_value The potentiometer selection bits (See DS11195C-page 14 Clause 4.1 Modes of Operation)
+         * @param p_command The command to execute (See DS11195C-page 18)
+         * @param p_set Set to true to shutdown, false to set up. Only used for _41xx/_42xx famillies (See DS22060B-page 36 REGISTER 4-2: TCON BITS)
          * @return 0x0000 on success, 0Xffff otherwise
          * Exemple:
          * @code
          * ...
          * g_chipSelect.write(0);
-         * g_digitalPot.Write(CMCP4xxxx_SPI::ShutdownPot1);
+         * g_digitalPot.Shutdown(CMCP4xxxx_SPI::ShutdownPot1);
          * g_chipSelect.write(1);
          * ...
          * @endcode
          */
-        unsigned short Write(const Commands p_command);
+        unsigned short Shutdown(const Commands p_command, const bool p_set = true);
     
          /** Write a NOP command
-         */
+          */
         unsigned short Write();
     
+         /** Change the current familly 
+          * @param familly The new type of ICs 
+          * @return the previous type of ICs 
+          */
+        Mcp4xxxFamilly SetFamilly(const Mcp4xxxFamilly familly);
+    
        /** Reset the device
-         * @code
-         * unsigned char potLevel;
-         * ...
-         * g_chipSelect.write(0);
-         * g_digitalPot.Reset();
-         * g_chipSelect.write(1);
-         * ...
-         * @endcode
-         */
-        bool Reset();
+        * @code
+        * unsigned char potLevel;
+        * ...
+        * g_digitalPot.Reset();
+        * ...
+        * @endcode
+        */
+        void Reset();
     
         /** Shutdown the device
          */
-        bool Shutdown(const bool p_set);
+        void Shutdown(const bool p_set);
     
     private:
-        /** Internal reference identifier
+        /** Internal reference identifier. Only used when /RS in is available
+         *
+         * @param p_set Set to true to shutdown, false to set up
          */
         std::string _internalId;