12-Bit DAC with internal Vref and SPI interface
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Diff: MCP4822.h
- Revision:
- 0:929babff65b1
- Child:
- 1:d97fd6c6e2e4
--- /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 \ No newline at end of file