MCP4822.h

00001 #ifndef __MCP4822_H__
00002 #define __MCP4822_H__
00003 
00004 #include "mbed.h"
00005 
00006 /** MCP4822 dual 12-bit DAC
00007 * @author NickRyder, atyeomans
00008 * @version 1.1
00009 * @section LICENSE
00010 * The MIT License (MIT)
00011 * Copyright (c) 2013 Nick Ryder, Andrew Yeomans
00012 * 
00013 * Permission is hereby granted, free of charge, to any person obtaining a copy
00014 * of this software and associated documentation files (the "Software"), to deal
00015 * in the Software without restriction, including without limitation the rights 
00016 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies 
00017 * of the Software, and to permit persons to whom the Software is furnished to do so,
00018 *  subject to the following conditions:
00019 *
00020 * The above copyright notice and this permission notice shall be included in all 
00021 * copies or substantial portions of the Software.
00022 *
00023 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
00024 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00025 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
00026 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
00027 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00028 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00029 */
00030 
00031 class MCP4822   {
00032     public:
00033         /** Create an MCP4822 instance
00034         * @param dataout SPI MOSI pin (should be p5 or p11)
00035         * @param clock  SPI clock pin (should be p7 or p13)
00036         * @param chipselect SPI chip select pin (can be any)
00037         * @param latch Latch pin updates the DAC out. Can be any pin or NC, if NC then the latch pin on the DAC chip should be held to GND.
00038         */
00039         MCP4822(PinName dataout, PinName clock, PinName chipselect, PinName latch);
00040         //! Set output A to voltage
00041         void setA(float voltage);
00042         //! Set output B to voltage
00043         void setB(float voltage);
00044         //! Set both output A to voltageA and outputB to voltageB
00045         void set(float voltageA, float voltageB);
00046         //! Latch the stored values to the output pins
00047         void latch();
00048         //! shut down output from the DAC chip
00049         void shutdown();
00050         //! shut down output form channel A
00051         void shutdownA();
00052         //! shut down output form channel B
00053         void shutdownB();
00054         //! Toggle chip select pin
00055         void chipSel();
00056     private:
00057         DigitalOut cs, latchpin;
00058         SPI spi;
00059         void write(bool chanB, bool gain1, unsigned int voltage, bool shutdown = false);
00060         void setvoltage(float voltage, bool chanB = false);
00061 };
00062 
00063 
00064 #endif