Diff: MCP320x_SPI.cpp

Revision:

0:17cee87e4563

Child:

1:f0a81abeaef5

--- /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