Diff: MCP4822.h

Revision:

0:929babff65b1

Child:

2:2b1457f78377

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MCP4822.h	Mon Mar 23 07:53:55 2015 +0000
@@ -0,0 +1,115 @@
+/* mbed MCP4822 Library, for driving the 12-Bit DAC with internal Vref and SPI interface
+ * Copyright (c) 2015, Created by Steen Joergensen (stjo2809)
+ *
+ * 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 "mbed.h"
+
+#ifndef MBED_MCP4822_H
+#define MBED_MCP4822_H
+
+//=============================================================================
+// Declaration of variables & custom #defines
+//=============================================================================
+
+#define CB_OUTPUT_A     0x00       // commad bit for output A
+#define CB_OUTPUT_B     0x80       // commad bit for output A
+#define CB_GAIN_1X      0x20       // commad bit for gain 1x
+#define CB_GAIN_2X      0x00       // commad bit for gain 2x
+#define CB_SHDN         0x10       // commad bit for Output enabled
+#define CB_NSHDN        0x00       // commad bit for Output buffer disabled, output is high-impedance
+
+//=============================================================================
+// Functions Declaration
+//=============================================================================
+
+/** Interface to the 12-Bit DAC with internal Vref and SPI interface
+ *
+  *  Using the driver:
+ *   - remenber to setup SPI in main routine or use pins instance.
+ *
+ *  Defaults in this driver on start up:
+ *   - Datasheet start up
+ */
+class MCP4822 {
+public:
+    /** Create an instance of the MCP4822 connected via specfied SPI instance.
+     *
+     * @param spi The mbed SPI instance (make in main routine)
+     * @param nLDAC The Latch DAC Synchronization pin 
+     * @param nCs The SPI chip select pin.
+     */
+    MCP4822(SPI& spi, PinName nLDAC, PinName nCs);
+    
+    /** Create an instance of the MCP4261 connected with SPI pins.
+     *
+     * @param nLDAC The Latch DAC Synchronization pin 
+     * @param mosi The SPI Master Output, Slave Input pin.
+     * @param miso The SPI Master Input, Slave Output pin. 
+     * @param sck The SPI Serial Clock pin.
+     * @param nCs The SPI chip select pin.
+     */
+    MCP4822(PinName nLDAC, PinName mosi, PinName miso,PinName sck, PinName nCs);
+    
+
+    /** Write to output A.
+     *
+     * @param gain the gain is 2x = '0' and 1x = '1'.
+     * @param data The 12 bits value to write to the output.
+     */
+    void a(bool gain, int data);
+    
+    /** Write to output B.
+     *
+     * @param gain the gain is 2x = '0' and 1x = '1'.
+     * @param data The 12 bits value to write to the output.
+     */
+    void b(bool gain, int data);
+    
+    /** Output Synchronization.
+     *
+     * @param act The LDAC is Active = true and Inactive = false.
+     */
+    void ldac(bool act);
+    
+    /** Output Shutdown.
+     *
+     * @param output A = '0' and B = '1'.
+     * @param act The SHDN is Active = true and Inactive = false.
+     */
+    void shdn(bool output, bool act);
+    
+  
+
+private:
+    SPI& _spi;
+    DigitalOut _nCs;
+    DigitalOut _nLDAC;
+    
+    char _upper_half;
+    char _lower_half;
+    
+    char _make_upper_half(bool output, bool gain, bool shdn, int data);
+    char _make_lower_half(int data);
+    void _write(bool output, bool gain, bool shdn, int data);             
+
+};
+
+#endif
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