Diff: MCP4922.h

Revision:

0:e5edc0373da0

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MCP4922.h	Sat May 07 19:27:14 2011 +0000
@@ -0,0 +1,80 @@
+/*
+ * MCP4922 - DAC library.
+ *
+ * Copyright (c) 2011 Steven Beard, UK Astronomy Technology Centre.
+ *
+ * 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 MCP4922_H
+#define MCP4922_H
+
+/* Reference: Microchip Technology (2005), MCP4821/MCP4822 DAC Data Sheet. */
+
+// MCP4922 reference voltage.
+#define MCP4922_VREF     2048    // Reference voltage (mV)
+
+/* Define possible combinations of 16-bit command register bits */
+#define MCP4922_REG_A1   0x3000  // Channel A gain 1
+#define MCP4922_REG_B1   0xB000  // Channel B gain 1
+#define MCP4922_REG_SHDN 0x0000  // Output power down
+
+class MCP4922 {
+public:
+
+    MCP4922 (PinName mosi, PinName sclk, PinName cs);
+
+    ~MCP4922();
+
+    /*+
+     * frequency: Set the SPI bus clock frequency in Hz.
+     *        The SPI bus frequency in Hz. Must be within the range
+     *        supported by both the SPI interface and the DAC chips
+     *        (~10 KHz to 20 MHz).
+     */
+    void frequency( int freq );
+    
+    void writeA(int value );
+    
+    void writeB(int value );
+
+    void write( int nchans, int values[], int gain=2, int latch=1 );
+
+    void latch_enable();
+    
+    void latch_disable();
+
+private:
+    
+    MCP4922( const MCP4922& rhs );
+    
+    void _init();
+
+    int _ndacs;              // The number of DACS in the array
+    int _latched;            // Is the "not LDAC" pin used (1=yes; 0=no)?
+    SPI _spi;                // SPI bus object for communicating with DAC.
+    DigitalOut** _ncs_array; // Array of pointers to DigitalOut objects
+    // connected to "not CS" pins.
+    DigitalOut* _nldac;      // Pointer to DigitalOut object connected
+    // to "not LDAC" pin (if any - NULL if none).
+};
+
+#endif