Yann Garcia / MCP4xxxx_SPI

Simplified access to a Microchip Digital Potentiometer (MCP41xxx/MCP42xxx) devices

Dependents:   MCP41xxxApp MCP320xApp MCP41xxxApp

MCP4xxxx_SPI.cpp@0:03314ad622d6, 2013-01-25 (annotated)

Committer:
Yann
Date:
Fri Jan 25 16:10:58 2013 +0000
Revision:
0:03314ad622d6
Child:
1:cf3cee91eb87
Create library and test application to support Microchip Digital Potentiometers MCP42xxx/MCP41xxx

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Yann 0:03314ad622d6 1 /* mbed simplified access to Microchip 24LCxx Serial EEPROM devices (SPI)
Yann 0:03314ad622d6 2 * Copyright (c) 2010-2012 ygarcia, MIT License
Yann 0:03314ad622d6 3 *
Yann 0:03314ad622d6 4 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
Yann 0:03314ad622d6 5 * and associated documentation files (the "Software"), to deal in the Software without restriction,
Yann 0:03314ad622d6 6 * including without limitation the rights to use, copy, modify, merge, publish, distribute,
Yann 0:03314ad622d6 7 * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
Yann 0:03314ad622d6 8 * furnished to do so, subject to the following conditions:
Yann 0:03314ad622d6 9 *
Yann 0:03314ad622d6 10 * The above copyright notice and this permission notice shall be included in all copies or
Yann 0:03314ad622d6 11 * substantial portions of the Software.
Yann 0:03314ad622d6 12 *
Yann 0:03314ad622d6 13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
Yann 0:03314ad622d6 14 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
Yann 0:03314ad622d6 15 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
Yann 0:03314ad622d6 16 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
Yann 0:03314ad622d6 17 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Yann 0:03314ad622d6 18 */
Yann 0:03314ad622d6 19
Yann 0:03314ad622d6 20 #include "MCP4xxxx_SPI.h"
Yann 0:03314ad622d6 21
Yann 0:03314ad622d6 22 namespace MCP4xxxx_SPI {
Yann 0:03314ad622d6 23
Yann 0:03314ad622d6 24 unsigned char CMCP4xxxx_SPI::SPIModuleRefCounter = 0;
Yann 0:03314ad622d6 25
Yann 0:03314ad622d6 26 CMCP4xxxx_SPI::CMCP4xxxx_SPI(const PinName p_mosi, const PinName p_miso, const PinName p_sclk, const PinName p_reset, const PinName p_shdn, const unsigned int p_frequency) : _internalId("") {
Yann 0:03314ad622d6 27 DEBUG_ENTER("CMCP4xxxx_SPI")
Yann 0:03314ad622d6 28
Yann 0:03314ad622d6 29 if (CMCP4xxxx_SPI::SPIModuleRefCounter != 0) {
Yann 0:03314ad622d6 30 error("CMCP4xxxx_SPI: Wrong params");
Yann 0:03314ad622d6 31 }
Yann 0:03314ad622d6 32
Yann 0:03314ad622d6 33 _spiInstance = new SPI(p_mosi, p_miso, p_sclk);
Yann 0:03314ad622d6 34 _spiInstance->frequency(p_frequency); // Set the frequency of the SPI interface
Yann 0:03314ad622d6 35 _spiInstance->format(16, 0); // See http://mbed.org/users/mbed_official/code/mbed/docs/0954ebd79f59//classmbed_1_1SPI.html
Yann 0:03314ad622d6 36 CMCP4xxxx_SPI::SPIModuleRefCounter += 1;
Yann 0:03314ad622d6 37 DEBUG_ENTER("CMCP4xxxx_SPI: refCounter=%d", CMCP4xxxx_SPI::SPIModuleRefCounter)
Yann 0:03314ad622d6 38
Yann 0:03314ad622d6 39 if (p_reset != NC) {
Yann 0:03314ad622d6 40 DEBUG("CMCP4xxxx_SPI: /RESET managed");
Yann 0:03314ad622d6 41 _reset = new DigitalOut(p_reset);
Yann 0:03314ad622d6 42 _reset->write(1); // Disable reset
Yann 0:03314ad622d6 43 } else {
Yann 0:03314ad622d6 44 DEBUG("CMCP4xxxx_SPI: /RESET not managed");
Yann 0:03314ad622d6 45 _reset = NULL; // Not used
Yann 0:03314ad622d6 46 }
Yann 0:03314ad622d6 47
Yann 0:03314ad622d6 48 if (p_shdn != NC) {
Yann 0:03314ad622d6 49 DEBUG("CMCP4xxxx_SPI: /SHDN managed");
Yann 0:03314ad622d6 50 _shdn = new DigitalOut(p_shdn);
Yann 0:03314ad622d6 51 _shdn->write(1); // Disable shutdown
Yann 0:03314ad622d6 52 } else {
Yann 0:03314ad622d6 53 DEBUG("CMCP4xxxx_SPI: /SHDN not managed");
Yann 0:03314ad622d6 54 _shdn = NULL; // Not used
Yann 0:03314ad622d6 55 }
Yann 0:03314ad622d6 56
Yann 0:03314ad622d6 57 DEBUG_LEAVE("CMCP4xxxx_SPI")
Yann 0:03314ad622d6 58 }
Yann 0:03314ad622d6 59
Yann 0:03314ad622d6 60 CMCP4xxxx_SPI::~CMCP4xxxx_SPI() {
Yann 0:03314ad622d6 61 DEBUG_ENTER("~CMCP4xxxx_SPI")
Yann 0:03314ad622d6 62
Yann 0:03314ad622d6 63 // Release I2C instance
Yann 0:03314ad622d6 64 DEBUG_ENTER("~CMCP4xxxx_SPI: refCounter=%d", CMCP4xxxx_SPI::SPIModuleRefCounter)
Yann 0:03314ad622d6 65 CMCP4xxxx_SPI::SPIModuleRefCounter -= 1;
Yann 0:03314ad622d6 66 if (CMCP4xxxx_SPI::SPIModuleRefCounter == 0) {
Yann 0:03314ad622d6 67 delete _spiInstance;
Yann 0:03314ad622d6 68 _spiInstance = NULL;
Yann 0:03314ad622d6 69 }
Yann 0:03314ad622d6 70 // Release _reset if required
Yann 0:03314ad622d6 71 if (_reset != NULL) {
Yann 0:03314ad622d6 72 _reset->write(0);
Yann 0:03314ad622d6 73 delete _reset;
Yann 0:03314ad622d6 74 }
Yann 0:03314ad622d6 75 // Release _shdn if required
Yann 0:03314ad622d6 76 if (_shdn != NULL) {
Yann 0:03314ad622d6 77 _shdn->write(0);
Yann 0:03314ad622d6 78 delete _shdn;
Yann 0:03314ad622d6 79 }
Yann 0:03314ad622d6 80
Yann 0:03314ad622d6 81 DEBUG_LEAVE("~CMCP4xxxx_SPI")
Yann 0:03314ad622d6 82 }
Yann 0:03314ad622d6 83
Yann 0:03314ad622d6 84 unsigned short CMCP4xxxx_SPI::Write(const Commands p_command, const unsigned char p_value) {
Yann 0:03314ad622d6 85 DEBUG_ENTER("CMCP4xxxx_SPI::Write: 0x%02x - 0x%02x", (unsigned char)p_command, p_value)
Yann 0:03314ad622d6 86
Yann 0:03314ad622d6 87 unsigned short command = 0;
Yann 0:03314ad622d6 88 switch (p_command) {
Yann 0:03314ad622d6 89 case WriteToPot1:
Yann 0:03314ad622d6 90 command = (0x11 << 8 | p_value);
Yann 0:03314ad622d6 91 break;
Yann 0:03314ad622d6 92 case WriteToPot2:
Yann 0:03314ad622d6 93 command = (0x12 << 8 | p_value);
Yann 0:03314ad622d6 94 break;
Yann 0:03314ad622d6 95 case WriteToPotBoth:
Yann 0:03314ad622d6 96 command = (0x13 << 8 | p_value);
Yann 0:03314ad622d6 97 break;
Yann 0:03314ad622d6 98 case ShutdownPot1:
Yann 0:03314ad622d6 99 command = (0x21 << 8);
Yann 0:03314ad622d6 100 break;
Yann 0:03314ad622d6 101 case ShutdownPot2:
Yann 0:03314ad622d6 102 command = (0x21 << 8);
Yann 0:03314ad622d6 103 break;
Yann 0:03314ad622d6 104 default: //<! Shutdown both digital potentiometers
Yann 0:03314ad622d6 105 command = (0x23 << 8);
Yann 0:03314ad622d6 106 } // End of 'switch' statement
Yann 0:03314ad622d6 107
Yann 0:03314ad622d6 108 DEBUG("CMCP4xxxx_SPI: Send command: 0x%04x", command)
Yann 0:03314ad622d6 109 unsigned short result = _spiInstance->write(command);
Yann 0:03314ad622d6 110
Yann 0:03314ad622d6 111 DEBUG_LEAVE("CMCP4xxxx_SPI::Write: %d", result)
Yann 0:03314ad622d6 112 return result;
Yann 0:03314ad622d6 113 }
Yann 0:03314ad622d6 114
Yann 0:03314ad622d6 115 unsigned short CMCP4xxxx_SPI::Write() {
Yann 0:03314ad622d6 116 return _spiInstance->write(0);
Yann 0:03314ad622d6 117 }
Yann 0:03314ad622d6 118
Yann 0:03314ad622d6 119 bool CMCP4xxxx_SPI::Reset() {
Yann 0:03314ad622d6 120 // Sanity check
Yann 0:03314ad622d6 121 if (_reset == NULL) {
Yann 0:03314ad622d6 122 return false;
Yann 0:03314ad622d6 123 }
Yann 0:03314ad622d6 124
Yann 0:03314ad622d6 125 _reset->write(0); // Set level low to activate reset
Yann 0:03314ad622d6 126 wait_us(1); // Wait for 1us
Yann 0:03314ad622d6 127 _reset->write(1); // Set level low to de-activate reset
Yann 0:03314ad622d6 128
Yann 0:03314ad622d6 129 return true;
Yann 0:03314ad622d6 130 }
Yann 0:03314ad622d6 131
Yann 0:03314ad622d6 132 bool CMCP4xxxx_SPI::Shutdown(const bool p_set) {
Yann 0:03314ad622d6 133 // Sanity check
Yann 0:03314ad622d6 134 if (_shdn == NULL) {
Yann 0:03314ad622d6 135 return false;
Yann 0:03314ad622d6 136 }
Yann 0:03314ad622d6 137
Yann 0:03314ad622d6 138 _shdn->write(p_set == false ? 0 : 1);
Yann 0:03314ad622d6 139
Yann 0:03314ad622d6 140 return true;
Yann 0:03314ad622d6 141 }
Yann 0:03314ad622d6 142
Yann 0:03314ad622d6 143 } // End of namespace MCP4xxxx_SPI