12-Bit DAC with internal Vref and SPI interface
Embed:
(wiki syntax)
Show/hide line numbers
MCP4822.h
00001 /* mbed MCP4822 Library, for driving the 12-Bit DAC with internal Vref and SPI interface 00002 * Copyright (c) 2015, Created by Steen Joergensen (stjo2809) 00003 * 00004 * Permission is hereby granted, free of charge, to any person obtaining a copy 00005 * of this software and associated documentation files (the "Software"), to deal 00006 * in the Software without restriction, including without limitation the rights 00007 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 00008 * copies of the Software, and to permit persons to whom the Software is 00009 * furnished to do so, subject to the following conditions: 00010 * 00011 * The above copyright notice and this permission notice shall be included in 00012 * all copies or substantial portions of the Software. 00013 * 00014 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 00015 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 00016 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 00017 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 00018 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 00019 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 00020 * THE SOFTWARE. 00021 */ 00022 00023 #include "mbed.h" 00024 00025 #ifndef MBED_MCP4822_H 00026 #define MBED_MCP4822_H 00027 00028 //============================================================================= 00029 // Declaration of variables & custom #defines 00030 //============================================================================= 00031 00032 #define CB_OUTPUT_A 0x00 // commad bit for output A 00033 #define CB_OUTPUT_B 0x80 // commad bit for output A 00034 #define CB_GAIN_1X 0x20 // commad bit for gain 1x 00035 #define CB_GAIN_2X 0x00 // commad bit for gain 2x 00036 #define CB_SHDN 0x10 // commad bit for Output enabled 00037 #define CB_NSHDN 0x00 // commad bit for Output buffer disabled, output is high-impedance 00038 00039 //============================================================================= 00040 // Functions Declaration 00041 //============================================================================= 00042 00043 /** Interface to the 12-Bit DAC with internal Vref and SPI interface 00044 * 00045 * Using the driver: 00046 * - remenber to setup SPI in main routine or use pins instance. 00047 * 00048 * Defaults in this driver on start up: 00049 * - Datasheet start up 00050 */ 00051 class MCP4822 { 00052 public: 00053 /** Create an instance of the MCP4822 connected via specfied SPI instance. 00054 * 00055 * @param spi The mbed SPI instance (make in main routine) 00056 * @param nLDAC The Latch DAC Synchronization pin 00057 * @param nCs The SPI chip select pin. 00058 */ 00059 MCP4822(SPI& spi, PinName nLDAC, PinName nCs); 00060 00061 /** Create an instance of the MCP4261 connected with SPI pins. 00062 * 00063 * @param nLDAC The Latch DAC Synchronization pin 00064 * @param mosi The SPI Master Output, Slave Input pin. 00065 * @param miso The SPI Master Input, Slave Output pin. 00066 * @param sck The SPI Serial Clock pin. 00067 * @param nCs The SPI chip select pin. 00068 */ 00069 MCP4822(PinName nLDAC, PinName mosi, PinName miso,PinName sck, PinName nCs); 00070 00071 00072 /** Write to output A. 00073 * 00074 * @param gain the gain is 2x = '0' and 1x = '1'. 00075 * @param data The 12 bits value to write to the output. 00076 */ 00077 void a(bool gain, int data); 00078 00079 /** Write to output B. 00080 * 00081 * @param gain the gain is 2x = '0' and 1x = '1'. 00082 * @param data The 12 bits value to write to the output. 00083 */ 00084 void b(bool gain, int data); 00085 00086 /** Output Synchronization. 00087 * 00088 * @param act The LDAC is Active = true and Inactive = false. 00089 */ 00090 void ldac(bool act); 00091 00092 /** Output Shutdown. 00093 * 00094 * @param output A = '0' and B = '1'. 00095 * @param act The SHDN is Active = true and Inactive = false. 00096 */ 00097 void shdn(bool output, bool act); 00098 00099 00100 00101 private: 00102 SPI& _spi; 00103 DigitalOut _nCs; 00104 DigitalOut _nLDAC; 00105 00106 char _upper_half; 00107 char _lower_half; 00108 00109 char _make_upper_half(bool output, bool gain, bool shdn, int data); 00110 char _make_lower_half(int data); 00111 void _write(bool output, bool gain, bool shdn, int data); 00112 00113 }; 00114 00115 #endif
Generated on Sat Jul 16 2022 14:19:40 by 1.7.2