12-Bit DAC with internal Vref and SPI interface
MCP4822.h
- Committer:
- stjo2809
- Date:
- 2015-03-23
- Revision:
- 0:929babff65b1
File content as of revision 0:929babff65b1:
/* 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