TeamElectronics / MCP4822

12-Bit DAC with internal Vref and SPI interface

MCP4822.h@0:929babff65b1, 2015-03-23 (annotated)

Committer:
stjo2809
Date:
Mon Mar 23 07:53:55 2015 +0000
Revision:
0:929babff65b1
revision 0.1

Who changed what in which revision?

UserRevisionLine numberNew contents of line
stjo2809 0:929babff65b1 1 /* mbed MCP4822 Library, for driving the 12-Bit DAC with internal Vref and SPI interface
stjo2809 0:929babff65b1 2 * Copyright (c) 2015, Created by Steen Joergensen (stjo2809)
stjo2809 0:929babff65b1 3 *
stjo2809 0:929babff65b1 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
stjo2809 0:929babff65b1 5 * of this software and associated documentation files (the "Software"), to deal
stjo2809 0:929babff65b1 6 * in the Software without restriction, including without limitation the rights
stjo2809 0:929babff65b1 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
stjo2809 0:929babff65b1 8 * copies of the Software, and to permit persons to whom the Software is
stjo2809 0:929babff65b1 9 * furnished to do so, subject to the following conditions:
stjo2809 0:929babff65b1 10 *
stjo2809 0:929babff65b1 11 * The above copyright notice and this permission notice shall be included in
stjo2809 0:929babff65b1 12 * all copies or substantial portions of the Software.
stjo2809 0:929babff65b1 13 *
stjo2809 0:929babff65b1 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
stjo2809 0:929babff65b1 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
stjo2809 0:929babff65b1 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
stjo2809 0:929babff65b1 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
stjo2809 0:929babff65b1 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
stjo2809 0:929babff65b1 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
stjo2809 0:929babff65b1 20 * THE SOFTWARE.
stjo2809 0:929babff65b1 21 */
stjo2809 0:929babff65b1 22
stjo2809 0:929babff65b1 23 #include "mbed.h"
stjo2809 0:929babff65b1 24
stjo2809 0:929babff65b1 25 #ifndef MBED_MCP4822_H
stjo2809 0:929babff65b1 26 #define MBED_MCP4822_H
stjo2809 0:929babff65b1 27
stjo2809 0:929babff65b1 28 //=============================================================================
stjo2809 0:929babff65b1 29 // Declaration of variables & custom #defines
stjo2809 0:929babff65b1 30 //=============================================================================
stjo2809 0:929babff65b1 31
stjo2809 0:929babff65b1 32 #define CB_OUTPUT_A 0x00 // commad bit for output A
stjo2809 0:929babff65b1 33 #define CB_OUTPUT_B 0x80 // commad bit for output A
stjo2809 0:929babff65b1 34 #define CB_GAIN_1X 0x20 // commad bit for gain 1x
stjo2809 0:929babff65b1 35 #define CB_GAIN_2X 0x00 // commad bit for gain 2x
stjo2809 0:929babff65b1 36 #define CB_SHDN 0x10 // commad bit for Output enabled
stjo2809 0:929babff65b1 37 #define CB_NSHDN 0x00 // commad bit for Output buffer disabled, output is high-impedance
stjo2809 0:929babff65b1 38
stjo2809 0:929babff65b1 39 //=============================================================================
stjo2809 0:929babff65b1 40 // Functions Declaration
stjo2809 0:929babff65b1 41 //=============================================================================
stjo2809 0:929babff65b1 42
stjo2809 0:929babff65b1 43 /** Interface to the 12-Bit DAC with internal Vref and SPI interface
stjo2809 0:929babff65b1 44 *
stjo2809 0:929babff65b1 45 * Using the driver:
stjo2809 0:929babff65b1 46 * - remenber to setup SPI in main routine or use pins instance.
stjo2809 0:929babff65b1 47 *
stjo2809 0:929babff65b1 48 * Defaults in this driver on start up:
stjo2809 0:929babff65b1 49 * - Datasheet start up
stjo2809 0:929babff65b1 50 */
stjo2809 0:929babff65b1 51 class MCP4822 {
stjo2809 0:929babff65b1 52 public:
stjo2809 0:929babff65b1 53 /** Create an instance of the MCP4822 connected via specfied SPI instance.
stjo2809 0:929babff65b1 54 *
stjo2809 0:929babff65b1 55 * @param spi The mbed SPI instance (make in main routine)
stjo2809 0:929babff65b1 56 * @param nLDAC The Latch DAC Synchronization pin
stjo2809 0:929babff65b1 57 * @param nCs The SPI chip select pin.
stjo2809 0:929babff65b1 58 */
stjo2809 0:929babff65b1 59 MCP4822(SPI& spi, PinName nLDAC, PinName nCs);
stjo2809 0:929babff65b1 60
stjo2809 0:929babff65b1 61 /** Create an instance of the MCP4261 connected with SPI pins.
stjo2809 0:929babff65b1 62 *
stjo2809 0:929babff65b1 63 * @param nLDAC The Latch DAC Synchronization pin
stjo2809 0:929babff65b1 64 * @param mosi The SPI Master Output, Slave Input pin.
stjo2809 0:929babff65b1 65 * @param miso The SPI Master Input, Slave Output pin.
stjo2809 0:929babff65b1 66 * @param sck The SPI Serial Clock pin.
stjo2809 0:929babff65b1 67 * @param nCs The SPI chip select pin.
stjo2809 0:929babff65b1 68 */
stjo2809 0:929babff65b1 69 MCP4822(PinName nLDAC, PinName mosi, PinName miso,PinName sck, PinName nCs);
stjo2809 0:929babff65b1 70
stjo2809 0:929babff65b1 71
stjo2809 0:929babff65b1 72 /** Write to output A.
stjo2809 0:929babff65b1 73 *
stjo2809 0:929babff65b1 74 * @param gain the gain is 2x = '0' and 1x = '1'.
stjo2809 0:929babff65b1 75 * @param data The 12 bits value to write to the output.
stjo2809 0:929babff65b1 76 */
stjo2809 0:929babff65b1 77 void a(bool gain, int data);
stjo2809 0:929babff65b1 78
stjo2809 0:929babff65b1 79 /** Write to output B.
stjo2809 0:929babff65b1 80 *
stjo2809 0:929babff65b1 81 * @param gain the gain is 2x = '0' and 1x = '1'.
stjo2809 0:929babff65b1 82 * @param data The 12 bits value to write to the output.
stjo2809 0:929babff65b1 83 */
stjo2809 0:929babff65b1 84 void b(bool gain, int data);
stjo2809 0:929babff65b1 85
stjo2809 0:929babff65b1 86 /** Output Synchronization.
stjo2809 0:929babff65b1 87 *
stjo2809 0:929babff65b1 88 * @param act The LDAC is Active = true and Inactive = false.
stjo2809 0:929babff65b1 89 */
stjo2809 0:929babff65b1 90 void ldac(bool act);
stjo2809 0:929babff65b1 91
stjo2809 0:929babff65b1 92 /** Output Shutdown.
stjo2809 0:929babff65b1 93 *
stjo2809 0:929babff65b1 94 * @param output A = '0' and B = '1'.
stjo2809 0:929babff65b1 95 * @param act The SHDN is Active = true and Inactive = false.
stjo2809 0:929babff65b1 96 */
stjo2809 0:929babff65b1 97 void shdn(bool output, bool act);
stjo2809 0:929babff65b1 98
stjo2809 0:929babff65b1 99
stjo2809 0:929babff65b1 100
stjo2809 0:929babff65b1 101 private:
stjo2809 0:929babff65b1 102 SPI& _spi;
stjo2809 0:929babff65b1 103 DigitalOut _nCs;
stjo2809 0:929babff65b1 104 DigitalOut _nLDAC;
stjo2809 0:929babff65b1 105
stjo2809 0:929babff65b1 106 char _upper_half;
stjo2809 0:929babff65b1 107 char _lower_half;
stjo2809 0:929babff65b1 108
stjo2809 0:929babff65b1 109 char _make_upper_half(bool output, bool gain, bool shdn, int data);
stjo2809 0:929babff65b1 110 char _make_lower_half(int data);
stjo2809 0:929babff65b1 111 void _write(bool output, bool gain, bool shdn, int data);
stjo2809 0:929babff65b1 112
stjo2809 0:929babff65b1 113 };
stjo2809 0:929babff65b1 114
stjo2809 0:929babff65b1 115 #endif