12-Bit DAC with internal Vref and SPI interface
Fork of MCP4822 by
Diff: MCP4822.cpp
- Revision:
- 0:929babff65b1
- Child:
- 1:d97fd6c6e2e4
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MCP4822.cpp Mon Mar 23 07:53:55 2015 +0000 @@ -0,0 +1,119 @@ +/* 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" + #include "MCP4822.h" + +//============================================================================= +// Public functions +//============================================================================= + + MCP4822::MCP4822(SPI& spi, PinName nLDAC, PinName nCs) : _spi(spi), _nLDAC(nLDAC), _nCs(nCs) + { + + } + + + MCP4822::MCP4822(PinName nLDAC, PinName mosi, PinName miso,PinName sck, PinName nCs) : _nLDAC(nLDAC), _mosi(mosi), _miso(miso), _sck(sck), _nCs(nCs) + { + SPI _spi(_mosi,_miso,_sck); + } + + void MCP4822::a(bool gain, int data) + { + _write(0, gain, 1, data); + } + + void MCP4822::b(bool gain, int data) + { + _write(1, gain, 1, data); + } + + void MCP4822::ldac(bool act) + { + _nLDAC = ~act; + } + + void MCP4822::shdn(bool output, bool act) + { + _write(output, 1, ~act, 0x00); + } + +//============================================================================= +// Private functions +//============================================================================= + + char MCP4822::_make_upper_half(bool output, bool gain, bool shdn, int data) + { + char responce = 0; + + if(output == '0') + { + responce = responce | CB_OUTPUT_A; + } + else + { + responce = responce | CB_OUTPUT_B; + } + + if(gain == '0') + { + responce = responce | CB_GAIN_2X; + } + else + { + responce = responce | CB_GAIN_1X; + } + + if(shdn == '0') + { + responce = responce | CB_NSHDN; + } + else + { + responce = responce | CB_SHDN; + } + + if(data > 0xff && data < 0xfff) + { + responce = responce | (data >> 8); + } + + return responce; + } + + char MCP4822::_make_lower_half(int data) + { + return (data & 0xff); + } + + void MCP4822::_write(bool output, bool gain, bool shdn, int data) + { + + _upper_half = _make_upper_half(output, gain, shdn, data); + _lower_half = _make_lower_half(data); + + _nCs = 0; + _spi.write(_upper_half); + _spi.write(_lower_half); + _nCs = 1; + } \ No newline at end of file