Revision 0:17cee87e4563, committed 2013-04-05

Comitter:

Yann

Date:

Fri Apr 05 13:38:09 2013 +0000

Child:

1:f0a81abeaef5

Commit message:

Add support of MCP3204/8

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MCP320x_SPI.cpp	Fri Apr 05 13:38:09 2013 +0000
@@ -0,0 +1,175 @@
+/* mbed simplified access to Microchip 12 bits ADC devices (SPI)
+ * Copyright (c) 2013 ygarcia, MIT License
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
+ * and associated documentation files (the "Software"), to deal in the Software without restriction, 
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, 
+ * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is 
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or 
+ * substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING 
+ * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include "MCP320x_SPI.h"
+
+namespace MCP320x_SPI {
+
+    unsigned char CMCP320x_SPI::SPIModuleRefCounter = 0;
+
+    CMCP320x_SPI::CMCP320x_SPI(const PinName p_mosi, const PinName p_miso, const PinName p_sclk, const PinName p_cs, const Mcp320xFamilly p_familly, const unsigned int p_frequency) : _internalId("") {
+        DEBUG_ENTER("CMCP320x_SPI")
+        
+        CMCP320x_SPI::SPIModuleRefCounter += 1;
+        if (CMCP320x_SPI::SPIModuleRefCounter > 1) {
+            //FIXME Check that SPI settings are identical. Otherwise it should failed
+            return;
+        }
+
+        _familly = p_familly;
+        switch (_familly) {
+            case _3201:
+                _channelsNum = 0;
+                break;
+            case _3204:
+                _channelsNum = 4;
+                break;
+            default: // _3208
+                _channelsNum = 8;
+        } // End of 'switch' statement
+        _settings = 0x02; // SGL/DIFF bit set to 1 = See DS21298E-page 19 TABLE 5-1: CONFIGURATION BITS FOR THE MCP3204/TABLE 5-2: CONFIGURATION BITS FOR THE MCP3208
+        DEBUG("CMCP320x_SPI: familly:%d - #channels:%d", _familly, _channelsNum)
+        _spiInstance = new SPI(p_mosi, p_miso, p_sclk);
+        _spiInstance->frequency(p_frequency); // Set the frequency of the SPI interface
+        _spiInstance->format(8, 3);
+        DEBUG_ENTER("CMCP320x_SPI: refCounter=%d", CMCP320x_SPI::SPIModuleRefCounter)
+
+        if (p_cs != NC) {
+            DEBUG("CMCP320x_SPI: /CS managed");
+            _cs = new DigitalOut(p_cs);
+            _cs->write(1); // Disable chip
+        } else {
+            DEBUG("CMCP320x_SPI: /CS not managed");
+            _cs = NULL; // Not used
+        }
+    
+   
+        DEBUG_LEAVE("CMCP320x_SPI")
+    }
+    
+    CMCP320x_SPI::~CMCP320x_SPI() {
+        DEBUG_ENTER("~CMCP320x_SPI")
+    
+        // Release I2C instance
+        DEBUG_ENTER("~CMCP320x_SPI: refCounter=%d", CMCP320x_SPI::SPIModuleRefCounter)
+        CMCP320x_SPI::SPIModuleRefCounter -= 1;
+        if (CMCP320x_SPI::SPIModuleRefCounter == 0) {
+            delete _spiInstance;
+            _spiInstance = NULL;
+        }
+        // Release _reset if required
+        if (_cs != NULL) {
+            _cs->write(1);
+            delete _cs;
+        }
+   
+        DEBUG_LEAVE("~CMCP320x_SPI")
+    }
+
+    float CMCP320x_SPI::Read(const Mcp320xChannels p_channels) {
+        DEBUG_ENTER("CMCP320x_SPI::Read: %d", (unsigned char)p_channels)
+        
+        // Read a sample
+        _sample.value = 0x00;
+        switch (_familly) {
+            case _3204:
+                // No break;
+            case _3208:
+                Read_320x(p_channels);
+                break;
+            default: // _3201
+                Read_3201();
+                break;
+        } // End of 'switch' statement 
+        DEBUG("CMCP320x_SPI::Read: 0x%02x - 0x%02x", _sample.bytes[0], _sample.bytes[1])
+        // Convert it
+        float temp;
+        _sample.value >>= 1; // Adjust composite integer for 12 valid bits
+        _sample.value &= 0x0FFF; // Mask out upper nibble of integer
+        temp = (_sample.value * 0.001225585);
+        
+        DEBUG_LEAVE("CMCP320x_SPI::Read: %f", temp)
+        return temp;        
+    }
+    
+    void CMCP320x_SPI::SetConfig(const bool p_settings) {
+        DEBUG_LEAVE("CMCP320x_SPI::SetConfig: %x", (unsigned char)p_settings)
+        
+        if (_settings) {
+            _settings = 0x02;
+        } else {
+            _settings = 0x00;
+        }
+    }
+    
+    bool CMCP320x_SPI::Shutdown(const bool p_shutdown) {
+        // Sanity check
+        if (_cs == NULL) {
+            return false;
+        }
+        
+        _cs->write(p_shutdown == false ? 0 : 1);
+        
+        return true;
+    }
+    
+    void CMCP320x_SPI::Read_3201() {
+        if (_cs != NULL) {
+            _cs->write(0);
+            wait_us(1);
+        }
+        _sample.bytes[1] = _spiInstance->write(0);
+        _sample.bytes[0] = _spiInstance->write(0);
+        if (_cs != NULL) {
+            _cs->write(1);
+        }    
+    }
+
+    void CMCP320x_SPI::Read_320x(const Mcp320xChannels p_channels) {
+        DEBUG_ENTER("CMCP320x_SPI::Read_320x: %d", (unsigned char)p_channels)
+        
+        unsigned char _channels = (unsigned char)p_channels % _channelsNum;
+        // Set start bit 
+        unsigned char mask = 0x04 | _settings; // Start bit set to 1 - See DS21298E-page 19 Clause 5.0 SERIAL COMMUNICATIONS
+        // Set channel address
+        unsigned char cmd0;
+        unsigned char cmd1;
+        if (_familly == _3204) {
+            cmd0 = mask;
+            cmd1 = _channels << 6; // MCP3204 has 4 channels in single-ended mode
+        } else { // MCP3208
+            cmd0 = mask | ((p_channels & 0x04) >> 2); // Extract D2 bit - See DS21298E-page 19 Clause 5.0 SERIAL COMMUNICATIONS
+            cmd1 = p_channels << 6; // MCP3204 has 8 channels in single-ended mode
+        }
+        DEBUG_ENTER("CMCP320x_SPI::Read_320x: comd0:%02x - cmd1:%02x", cmd0, cmd1)
+        if (_cs != NULL) {
+            _cs->write(0);
+            wait_us(1);
+        }
+        _spiInstance->write(cmd0); // Don't care of the result - See DS21298E-page 21 Clause 6.1 Using the MCP3204/3208 with Microcontroller (MCU) SPI Ports
+        _sample.bytes[1] = _spiInstance->write(cmd1); // DS21298E-page 21 See FIGURE 6-1: SPI Communication using 8-bit segments (Mode 0,0: SCLK idles low)
+        _sample.bytes[0] = _spiInstance->write(0);
+        if (_cs != NULL) {
+            _cs->write(1);
+        }
+            
+        DEBUG_LEAVE("CMCP320x_SPI::Read_320x")
+    }
+    
+} // End of namespace MCP320x_SPI

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MCP320x_SPI.h	Fri Apr 05 13:38:09 2013 +0000
@@ -0,0 +1,154 @@
+/* mbed simplified access to Microchip MCP320x 12 bits ADC devices (SPI)
+ * Copyright (c) 2013-2013 ygarcia, MIT License
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
+ * and associated documentation files (the "Software"), to deal in the Software without restriction, 
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, 
+ * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is 
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or 
+ * substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING 
+ * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#if !defined(__MCP320x_SPI_H__)
+#define __MCP320x_SPI_H__
+
+#include <string>
+#include <vector>
+
+#include "Debug.h" // Include mbed header + debug primitives. See DebugLibrary
+
+namespace MCP320x_SPI {
+
+    /** This class provides simplified SPI access to a Microchip MCP320x 12-Bit A/D Converter with SPI Serial Interface device. V0.0.0.1
+     *
+     * Microchip MCP42xxx/MCP41xxx Serial EEPROM device reference: DS11195C
+     *
+     * Note that MCP3201 has no SI pin, only a SO output pin
+     * 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
+     * @author Yann Garcia (Don't hesitate to contact me: garcia.yann@gmail.com)
+     */
+    class CMCP320x_SPI { 
+        /** Reference counter used to guarentee unicity of the instance of SPI class
+         */
+        static unsigned char SPIModuleRefCounter;
+        
+        /** ChipSelect (pin 1) see DS21290F-page 15 Clause 3.3 Chip Select/Shutdown (CS/SHDN)
+         */
+        DigitalOut *_cs;
+        
+        /** An unique instance of SPI class
+         */
+        SPI *_spiInstance;
+        
+        /** ADC sample structure
+         */
+        typedef union {
+            unsigned int value;
+            struct {
+                unsigned char bytes[2];
+            };
+        } ADCValue;
+        ADCValue _sample;
+        /** Number of channels according to the IC type 
+         */
+        unsigned char _channelsNum;
+        /** Set to true for single-ended inputs configuration, false for pseudo-differential inputs
+         * @see DS21298E-page 19 Clause 5.0 SERIAL COMMUNICATIONS
+         */
+        unsigned char _settings;
+   public:
+        /** MCP320x familly
+         */
+        enum Mcp320xFamilly {
+            _3201 = 0x00, /** See DS21290F */
+            _3204 = 0x01, /** See DS21298E */
+            _3208 = 0x03  /** See DS21298E */
+        };
+        Mcp320xFamilly _familly;
+        /** MCP320x channels to read
+         */
+        enum Mcp320xChannels {
+            CH0 = 0x00, /** See DS21290F/DS21290F */
+            CH1 = 0x01, /** See DS21298E */
+            CH2 = 0x02, /** See DS21298E */
+            CH3 = 0x03, /** See DS21298E */
+            CH4 = 0x04, /** See DS21298E */
+            CH5 = 0x05, /** See DS21298E */
+            CH6 = 0x06, /** See DS21298E */
+            CH7 = 0x07  /** See DS21298E */
+        };
+   public:
+        /** Constructor with Write Protect command pin wired.
+         *
+         * @param p_mosi: MBed pin for SDI
+         * @param p_miso: MBed pin for SDO
+         * @param p_sclk: MBed pin for CLK
+         * @param p_cs  : MBed pin for Chip Select. If NC, assumes that application manage /CS, default value is NC, not connected
+         * @param p_familly: MCP320x familly. Default: _3201
+         * @param p_frequency: Frequency of the SPI interface (SCK), default value is 1MHz
+         */
+        CMCP320x_SPI(const PinName p_mosi, const PinName p_miso, const PinName p_sclk, const PinName p_cs = NC, const Mcp320xFamilly p_familly = _3201, const unsigned int p_frequency = 1000000);
+    
+        /** Destructor
+         * If managed, the /CS pin is set to 1 before to release it
+         */
+        virtual ~CMCP320x_SPI();
+
+        /** Used to return the unique instance of SPI instance
+         */
+        inline const SPI * operator * () { return (const SPI *)_spiInstance; };
+
+        /** 
+         * @desc Launch an analog to digital conversion on the specified channel
+         * @param p_channel The channel to convert
+         * @return The converted value
+         */
+        float Read(const Mcp320xChannels p_channels = CH1);
+        
+        /** 
+         * @desc Change current configuration (only for MCP3204/8)
+         * @param p_setConfig Set to true for single-ended inputs configuration, false for pseudo-differential inputs
+         * @see DS21298E-page 17 Clause 4.1 Analog Inputs
+         */
+        void SetConfig(const bool p_settings);
+    
+         /** Shutdown the device
+         */
+        bool Shutdown(const bool p_shutdown);
+    
+   private:
+        /** Internal reference identifier
+         */
+        std::string _internalId;
+        
+    private:
+    
+        /** 
+         * @desc Launch an analog to digital conversion on the specified channel for MCP3201
+         * @see DS21290F-page 17 Clause 4.1 Analog Inputs
+         */
+        void Read_3201();
+        
+        /** 
+         * @desc Launch an analog to digital conversion on the specified channel for MCP3204/8
+         * @param p_setConfig Set to true for single-ended inputs configuration, false for pseudo-differential inputs
+         * @see DS21298E-page 17 Clause 4.1 Analog Inputs
+         */
+        void Read_320x(const Mcp320xChannels p_channels);    
+        
+    }; // End of class CMCP320x_SPI
+
+} // End of namespace MCP320x_SPI
+
+using namespace MCP320x_SPI;
+
+#endif // __MCP320x_SPI_H__