Simplified access to the Microchip 1//8-Channels 12-Bit A/D Converters with SPI Serial Interface
MCP320x_SPI.cpp@2:a273b5fcad50, 2013-09-05 (annotated)
- Committer:
- Yann
- Date:
- Thu Sep 05 07:22:02 2013 +0000
- Revision:
- 2:a273b5fcad50
- Parent:
- 1:f0a81abeaef5
Minor bug fixed; Method name changed: Incrememt -> Increment
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
Yann | 0:17cee87e4563 | 1 | /* mbed simplified access to Microchip 12 bits ADC devices (SPI) |
Yann | 0:17cee87e4563 | 2 | * Copyright (c) 2013 ygarcia, MIT License |
Yann | 0:17cee87e4563 | 3 | * |
Yann | 0:17cee87e4563 | 4 | * Permission is hereby granted, free of charge, to any person obtaining a copy of this software |
Yann | 0:17cee87e4563 | 5 | * and associated documentation files (the "Software"), to deal in the Software without restriction, |
Yann | 0:17cee87e4563 | 6 | * including without limitation the rights to use, copy, modify, merge, publish, distribute, |
Yann | 0:17cee87e4563 | 7 | * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is |
Yann | 0:17cee87e4563 | 8 | * furnished to do so, subject to the following conditions: |
Yann | 0:17cee87e4563 | 9 | * |
Yann | 0:17cee87e4563 | 10 | * The above copyright notice and this permission notice shall be included in all copies or |
Yann | 0:17cee87e4563 | 11 | * substantial portions of the Software. |
Yann | 0:17cee87e4563 | 12 | * |
Yann | 0:17cee87e4563 | 13 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING |
Yann | 0:17cee87e4563 | 14 | * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
Yann | 0:17cee87e4563 | 15 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, |
Yann | 0:17cee87e4563 | 16 | * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
Yann | 0:17cee87e4563 | 17 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
Yann | 0:17cee87e4563 | 18 | */ |
Yann | 0:17cee87e4563 | 19 | |
Yann | 0:17cee87e4563 | 20 | #include "MCP320x_SPI.h" |
Yann | 0:17cee87e4563 | 21 | |
Yann | 0:17cee87e4563 | 22 | namespace MCP320x_SPI { |
Yann | 0:17cee87e4563 | 23 | |
Yann | 0:17cee87e4563 | 24 | unsigned char CMCP320x_SPI::SPIModuleRefCounter = 0; |
Yann | 0:17cee87e4563 | 25 | |
Yann | 0:17cee87e4563 | 26 | CMCP320x_SPI::CMCP320x_SPI(const PinName p_mosi, const PinName p_miso, const PinName p_sclk, const PinName p_cs, const Mcp320xFamilly p_familly, const unsigned int p_frequency) : _internalId("") { |
Yann | 0:17cee87e4563 | 27 | DEBUG_ENTER("CMCP320x_SPI") |
Yann | 0:17cee87e4563 | 28 | |
Yann | 0:17cee87e4563 | 29 | CMCP320x_SPI::SPIModuleRefCounter += 1; |
Yann | 0:17cee87e4563 | 30 | if (CMCP320x_SPI::SPIModuleRefCounter > 1) { |
Yann | 0:17cee87e4563 | 31 | //FIXME Check that SPI settings are identical. Otherwise it should failed |
Yann | 0:17cee87e4563 | 32 | return; |
Yann | 0:17cee87e4563 | 33 | } |
Yann | 0:17cee87e4563 | 34 | |
Yann | 0:17cee87e4563 | 35 | _familly = p_familly; |
Yann | 0:17cee87e4563 | 36 | switch (_familly) { |
Yann | 0:17cee87e4563 | 37 | case _3201: |
Yann | 2:a273b5fcad50 | 38 | _channelsNum = 1; |
Yann | 0:17cee87e4563 | 39 | break; |
Yann | 0:17cee87e4563 | 40 | case _3204: |
Yann | 0:17cee87e4563 | 41 | _channelsNum = 4; |
Yann | 0:17cee87e4563 | 42 | break; |
Yann | 0:17cee87e4563 | 43 | default: // _3208 |
Yann | 0:17cee87e4563 | 44 | _channelsNum = 8; |
Yann | 0:17cee87e4563 | 45 | } // End of 'switch' statement |
Yann | 0:17cee87e4563 | 46 | _settings = 0x02; // SGL/DIFF bit set to 1 = See DS21298E-page 19 TABLE 5-1: CONFIGURATION BITS FOR THE MCP3204/TABLE 5-2: CONFIGURATION BITS FOR THE MCP3208 |
Yann | 0:17cee87e4563 | 47 | DEBUG("CMCP320x_SPI: familly:%d - #channels:%d", _familly, _channelsNum) |
Yann | 0:17cee87e4563 | 48 | _spiInstance = new SPI(p_mosi, p_miso, p_sclk); |
Yann | 0:17cee87e4563 | 49 | _spiInstance->frequency(p_frequency); // Set the frequency of the SPI interface |
Yann | 0:17cee87e4563 | 50 | _spiInstance->format(8, 3); |
Yann | 0:17cee87e4563 | 51 | DEBUG_ENTER("CMCP320x_SPI: refCounter=%d", CMCP320x_SPI::SPIModuleRefCounter) |
Yann | 0:17cee87e4563 | 52 | |
Yann | 0:17cee87e4563 | 53 | if (p_cs != NC) { |
Yann | 0:17cee87e4563 | 54 | DEBUG("CMCP320x_SPI: /CS managed"); |
Yann | 0:17cee87e4563 | 55 | _cs = new DigitalOut(p_cs); |
Yann | 0:17cee87e4563 | 56 | _cs->write(1); // Disable chip |
Yann | 0:17cee87e4563 | 57 | } else { |
Yann | 0:17cee87e4563 | 58 | DEBUG("CMCP320x_SPI: /CS not managed"); |
Yann | 0:17cee87e4563 | 59 | _cs = NULL; // Not used |
Yann | 0:17cee87e4563 | 60 | } |
Yann | 0:17cee87e4563 | 61 | |
Yann | 0:17cee87e4563 | 62 | |
Yann | 0:17cee87e4563 | 63 | DEBUG_LEAVE("CMCP320x_SPI") |
Yann | 0:17cee87e4563 | 64 | } |
Yann | 0:17cee87e4563 | 65 | |
Yann | 0:17cee87e4563 | 66 | CMCP320x_SPI::~CMCP320x_SPI() { |
Yann | 0:17cee87e4563 | 67 | DEBUG_ENTER("~CMCP320x_SPI") |
Yann | 0:17cee87e4563 | 68 | |
Yann | 0:17cee87e4563 | 69 | // Release I2C instance |
Yann | 0:17cee87e4563 | 70 | DEBUG_ENTER("~CMCP320x_SPI: refCounter=%d", CMCP320x_SPI::SPIModuleRefCounter) |
Yann | 0:17cee87e4563 | 71 | CMCP320x_SPI::SPIModuleRefCounter -= 1; |
Yann | 0:17cee87e4563 | 72 | if (CMCP320x_SPI::SPIModuleRefCounter == 0) { |
Yann | 0:17cee87e4563 | 73 | delete _spiInstance; |
Yann | 0:17cee87e4563 | 74 | _spiInstance = NULL; |
Yann | 0:17cee87e4563 | 75 | } |
Yann | 0:17cee87e4563 | 76 | // Release _reset if required |
Yann | 0:17cee87e4563 | 77 | if (_cs != NULL) { |
Yann | 0:17cee87e4563 | 78 | _cs->write(1); |
Yann | 0:17cee87e4563 | 79 | delete _cs; |
Yann | 0:17cee87e4563 | 80 | } |
Yann | 0:17cee87e4563 | 81 | |
Yann | 0:17cee87e4563 | 82 | DEBUG_LEAVE("~CMCP320x_SPI") |
Yann | 0:17cee87e4563 | 83 | } |
Yann | 0:17cee87e4563 | 84 | |
Yann | 0:17cee87e4563 | 85 | float CMCP320x_SPI::Read(const Mcp320xChannels p_channels) { |
Yann | 0:17cee87e4563 | 86 | DEBUG_ENTER("CMCP320x_SPI::Read: %d", (unsigned char)p_channels) |
Yann | 0:17cee87e4563 | 87 | |
Yann | 0:17cee87e4563 | 88 | // Read a sample |
Yann | 0:17cee87e4563 | 89 | _sample.value = 0x00; |
Yann | 0:17cee87e4563 | 90 | switch (_familly) { |
Yann | 0:17cee87e4563 | 91 | case _3204: |
Yann | 0:17cee87e4563 | 92 | // No break; |
Yann | 0:17cee87e4563 | 93 | case _3208: |
Yann | 0:17cee87e4563 | 94 | Read_320x(p_channels); |
Yann | 0:17cee87e4563 | 95 | break; |
Yann | 0:17cee87e4563 | 96 | default: // _3201 |
Yann | 0:17cee87e4563 | 97 | Read_3201(); |
Yann | 0:17cee87e4563 | 98 | break; |
Yann | 0:17cee87e4563 | 99 | } // End of 'switch' statement |
Yann | 0:17cee87e4563 | 100 | DEBUG("CMCP320x_SPI::Read: 0x%02x - 0x%02x", _sample.bytes[0], _sample.bytes[1]) |
Yann | 0:17cee87e4563 | 101 | // Convert it |
Yann | 0:17cee87e4563 | 102 | float temp; |
Yann | 0:17cee87e4563 | 103 | _sample.value >>= 1; // Adjust composite integer for 12 valid bits |
Yann | 0:17cee87e4563 | 104 | _sample.value &= 0x0FFF; // Mask out upper nibble of integer |
Yann | 0:17cee87e4563 | 105 | temp = (_sample.value * 0.001225585); |
Yann | 0:17cee87e4563 | 106 | |
Yann | 0:17cee87e4563 | 107 | DEBUG_LEAVE("CMCP320x_SPI::Read: %f", temp) |
Yann | 0:17cee87e4563 | 108 | return temp; |
Yann | 0:17cee87e4563 | 109 | } |
Yann | 0:17cee87e4563 | 110 | |
Yann | 0:17cee87e4563 | 111 | void CMCP320x_SPI::SetConfig(const bool p_settings) { |
Yann | 0:17cee87e4563 | 112 | DEBUG_LEAVE("CMCP320x_SPI::SetConfig: %x", (unsigned char)p_settings) |
Yann | 0:17cee87e4563 | 113 | |
Yann | 0:17cee87e4563 | 114 | if (_settings) { |
Yann | 0:17cee87e4563 | 115 | _settings = 0x02; |
Yann | 0:17cee87e4563 | 116 | } else { |
Yann | 0:17cee87e4563 | 117 | _settings = 0x00; |
Yann | 0:17cee87e4563 | 118 | } |
Yann | 0:17cee87e4563 | 119 | } |
Yann | 0:17cee87e4563 | 120 | |
Yann | 0:17cee87e4563 | 121 | bool CMCP320x_SPI::Shutdown(const bool p_shutdown) { |
Yann | 0:17cee87e4563 | 122 | // Sanity check |
Yann | 0:17cee87e4563 | 123 | if (_cs == NULL) { |
Yann | 0:17cee87e4563 | 124 | return false; |
Yann | 0:17cee87e4563 | 125 | } |
Yann | 0:17cee87e4563 | 126 | |
Yann | 0:17cee87e4563 | 127 | _cs->write(p_shutdown == false ? 0 : 1); |
Yann | 0:17cee87e4563 | 128 | |
Yann | 0:17cee87e4563 | 129 | return true; |
Yann | 0:17cee87e4563 | 130 | } |
Yann | 0:17cee87e4563 | 131 | |
Yann | 0:17cee87e4563 | 132 | void CMCP320x_SPI::Read_3201() { |
Yann | 0:17cee87e4563 | 133 | if (_cs != NULL) { |
Yann | 0:17cee87e4563 | 134 | _cs->write(0); |
Yann | 0:17cee87e4563 | 135 | wait_us(1); |
Yann | 0:17cee87e4563 | 136 | } |
Yann | 0:17cee87e4563 | 137 | _sample.bytes[1] = _spiInstance->write(0); |
Yann | 0:17cee87e4563 | 138 | _sample.bytes[0] = _spiInstance->write(0); |
Yann | 0:17cee87e4563 | 139 | if (_cs != NULL) { |
Yann | 0:17cee87e4563 | 140 | _cs->write(1); |
Yann | 0:17cee87e4563 | 141 | } |
Yann | 0:17cee87e4563 | 142 | } |
Yann | 0:17cee87e4563 | 143 | |
Yann | 0:17cee87e4563 | 144 | void CMCP320x_SPI::Read_320x(const Mcp320xChannels p_channels) { |
Yann | 0:17cee87e4563 | 145 | DEBUG_ENTER("CMCP320x_SPI::Read_320x: %d", (unsigned char)p_channels) |
Yann | 0:17cee87e4563 | 146 | |
Yann | 0:17cee87e4563 | 147 | unsigned char _channels = (unsigned char)p_channels % _channelsNum; |
Yann | 0:17cee87e4563 | 148 | // Set start bit |
Yann | 0:17cee87e4563 | 149 | unsigned char mask = 0x04 | _settings; // Start bit set to 1 - See DS21298E-page 19 Clause 5.0 SERIAL COMMUNICATIONS |
Yann | 0:17cee87e4563 | 150 | // Set channel address |
Yann | 0:17cee87e4563 | 151 | unsigned char cmd0; |
Yann | 0:17cee87e4563 | 152 | unsigned char cmd1; |
Yann | 0:17cee87e4563 | 153 | if (_familly == _3204) { |
Yann | 0:17cee87e4563 | 154 | cmd0 = mask; |
Yann | 0:17cee87e4563 | 155 | cmd1 = _channels << 6; // MCP3204 has 4 channels in single-ended mode |
Yann | 0:17cee87e4563 | 156 | } else { // MCP3208 |
Yann | 2:a273b5fcad50 | 157 | cmd0 = mask | ((_channels & 0x04) >> 2); // Extract D2 bit - See DS21298E-page 19 Clause 5.0 SERIAL COMMUNICATIONS |
Yann | 2:a273b5fcad50 | 158 | cmd1 = _channels << 6; // MCP3204 has 8 channels in single-ended mode |
Yann | 0:17cee87e4563 | 159 | } |
Yann | 2:a273b5fcad50 | 160 | DEBUG("CMCP320x_SPI::Read_320x: cmd0:%02x - cmd1:%02x", cmd0, cmd1) |
Yann | 0:17cee87e4563 | 161 | if (_cs != NULL) { |
Yann | 0:17cee87e4563 | 162 | _cs->write(0); |
Yann | 0:17cee87e4563 | 163 | wait_us(1); |
Yann | 0:17cee87e4563 | 164 | } |
Yann | 0:17cee87e4563 | 165 | _spiInstance->write(cmd0); // Don't care of the result - See DS21298E-page 21 Clause 6.1 Using the MCP3204/3208 with Microcontroller (MCU) SPI Ports |
Yann | 0:17cee87e4563 | 166 | _sample.bytes[1] = _spiInstance->write(cmd1); // DS21298E-page 21 See FIGURE 6-1: SPI Communication using 8-bit segments (Mode 0,0: SCLK idles low) |
Yann | 0:17cee87e4563 | 167 | _sample.bytes[0] = _spiInstance->write(0); |
Yann | 0:17cee87e4563 | 168 | if (_cs != NULL) { |
Yann | 0:17cee87e4563 | 169 | _cs->write(1); |
Yann | 0:17cee87e4563 | 170 | } |
Yann | 0:17cee87e4563 | 171 | |
Yann | 0:17cee87e4563 | 172 | DEBUG_LEAVE("CMCP320x_SPI::Read_320x") |
Yann | 0:17cee87e4563 | 173 | } |
Yann | 0:17cee87e4563 | 174 | |
Yann | 0:17cee87e4563 | 175 | } // End of namespace MCP320x_SPI |