Interface for an LIS302 accelerometer, using the SPI interface
Dependents: LIS302_HelloWorld mbed_line_camera
LIS302.cpp@1:fe7ccd3480e6, 2010-06-08 (annotated)
- Committer:
- simon
- Date:
- Tue Jun 08 13:34:48 2010 +0000
- Revision:
- 1:fe7ccd3480e6
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
simon | 1:fe7ccd3480e6 | 1 | /* mbed LIS302 Accelerometer Library |
simon | 1:fe7ccd3480e6 | 2 | * Copyright (c) 2008-2010, sford, cstyles, wreynolds |
simon | 1:fe7ccd3480e6 | 3 | * |
simon | 1:fe7ccd3480e6 | 4 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
simon | 1:fe7ccd3480e6 | 5 | * of this software and associated documentation files (the "Software"), to deal |
simon | 1:fe7ccd3480e6 | 6 | * in the Software without restriction, including without limitation the rights |
simon | 1:fe7ccd3480e6 | 7 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
simon | 1:fe7ccd3480e6 | 8 | * copies of the Software, and to permit persons to whom the Software is |
simon | 1:fe7ccd3480e6 | 9 | * furnished to do so, subject to the following conditions: |
simon | 1:fe7ccd3480e6 | 10 | * |
simon | 1:fe7ccd3480e6 | 11 | * The above copyright notice and this permission notice shall be included in |
simon | 1:fe7ccd3480e6 | 12 | * all copies or substantial portions of the Software. |
simon | 1:fe7ccd3480e6 | 13 | * |
simon | 1:fe7ccd3480e6 | 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
simon | 1:fe7ccd3480e6 | 15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
simon | 1:fe7ccd3480e6 | 16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
simon | 1:fe7ccd3480e6 | 17 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
simon | 1:fe7ccd3480e6 | 18 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
simon | 1:fe7ccd3480e6 | 19 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
simon | 1:fe7ccd3480e6 | 20 | * THE SOFTWARE. |
simon | 1:fe7ccd3480e6 | 21 | */ |
simon | 1:fe7ccd3480e6 | 22 | |
simon | 1:fe7ccd3480e6 | 23 | #include "LIS302.h" |
simon | 1:fe7ccd3480e6 | 24 | #include "mbed.h" |
simon | 1:fe7ccd3480e6 | 25 | |
simon | 1:fe7ccd3480e6 | 26 | #define LIS302_WHOAMI 0x0F |
simon | 1:fe7ccd3480e6 | 27 | #define LIS302_CTRL_REG1 0x20 |
simon | 1:fe7ccd3480e6 | 28 | #define LIS302_CTRL_REG2 0x21 |
simon | 1:fe7ccd3480e6 | 29 | #define LIS302_CTRL_REG3 0x22 |
simon | 1:fe7ccd3480e6 | 30 | #define LIS302_HP_FILTER_RST 0x23 |
simon | 1:fe7ccd3480e6 | 31 | #define LIS302_STATUS_REG 0x27 |
simon | 1:fe7ccd3480e6 | 32 | #define LIS302_OUTX 0x29 |
simon | 1:fe7ccd3480e6 | 33 | #define LIS302_OUTY 0x2B |
simon | 1:fe7ccd3480e6 | 34 | #define LIS302_OUTZ 0x2D |
simon | 1:fe7ccd3480e6 | 35 | #define LIS302_FF_WU_CFG1 0x30 |
simon | 1:fe7ccd3480e6 | 36 | #define LIS302_FF_WU_SRC_1 0x31 |
simon | 1:fe7ccd3480e6 | 37 | #define LIS302_FF_WU_THS_1 0x32 |
simon | 1:fe7ccd3480e6 | 38 | #define LIS302_FF_WU_DURATION_1 0x33 |
simon | 1:fe7ccd3480e6 | 39 | #define LIS302_FF_WU_CFG_2 0x34 |
simon | 1:fe7ccd3480e6 | 40 | #define LIS302_FF_WU_SRC_2 0x35 |
simon | 1:fe7ccd3480e6 | 41 | #define LIS302_FF_WU_THS_2 0x36 |
simon | 1:fe7ccd3480e6 | 42 | #define LIS302_FF_WU_DURATION_2 0x37 |
simon | 1:fe7ccd3480e6 | 43 | #define LIS302_CLICK_CFG 0x38 |
simon | 1:fe7ccd3480e6 | 44 | #define LIS302_CLICK_SRC 0x39 |
simon | 1:fe7ccd3480e6 | 45 | #define LIS302_CLICK_THSY_X 0x3B |
simon | 1:fe7ccd3480e6 | 46 | #define LIS302_CLICK_THSZ 0x3C |
simon | 1:fe7ccd3480e6 | 47 | #define LIS302_READ 0x80 |
simon | 1:fe7ccd3480e6 | 48 | #define LIS302_WRITE 0x00 |
simon | 1:fe7ccd3480e6 | 49 | |
simon | 1:fe7ccd3480e6 | 50 | #define LIS302_STATUS_X_AVAILABLE 0x1 |
simon | 1:fe7ccd3480e6 | 51 | #define LIS302_STATUS_Y_AVAILABLE 0x2 |
simon | 1:fe7ccd3480e6 | 52 | #define LIS302_STATUS_Z_AVAILABLE 0x4 |
simon | 1:fe7ccd3480e6 | 53 | |
simon | 1:fe7ccd3480e6 | 54 | #define FACTOR_2g 55.6 |
simon | 1:fe7ccd3480e6 | 55 | #define FACTOR_8g 13.9 |
simon | 1:fe7ccd3480e6 | 56 | |
simon | 1:fe7ccd3480e6 | 57 | LIS302::LIS302(PinName mosi, PinName miso, PinName clk, PinName ncs) |
simon | 1:fe7ccd3480e6 | 58 | : _spi(mosi, miso, clk), _ncs(ncs) { |
simon | 1:fe7ccd3480e6 | 59 | |
simon | 1:fe7ccd3480e6 | 60 | // Make sure CS is high |
simon | 1:fe7ccd3480e6 | 61 | _ncs = 1; |
simon | 1:fe7ccd3480e6 | 62 | |
simon | 1:fe7ccd3480e6 | 63 | // Set up the spi interface |
simon | 1:fe7ccd3480e6 | 64 | _spi.format(8, 3); |
simon | 1:fe7ccd3480e6 | 65 | _spi.frequency(1000000); |
simon | 1:fe7ccd3480e6 | 66 | |
simon | 1:fe7ccd3480e6 | 67 | // Write to CTRL_REG1 |
simon | 1:fe7ccd3480e6 | 68 | _ncs = 0; |
simon | 1:fe7ccd3480e6 | 69 | _spi.write(LIS302_WRITE | LIS302_CTRL_REG1); |
simon | 1:fe7ccd3480e6 | 70 | _spi.write (0x47); |
simon | 1:fe7ccd3480e6 | 71 | _ncs = 1; |
simon | 1:fe7ccd3480e6 | 72 | |
simon | 1:fe7ccd3480e6 | 73 | // Write to CTRL_REG2 |
simon | 1:fe7ccd3480e6 | 74 | _ncs = 0; |
simon | 1:fe7ccd3480e6 | 75 | _spi.write(LIS302_WRITE | LIS302_CTRL_REG2); |
simon | 1:fe7ccd3480e6 | 76 | _spi.write (0x0); // This is default anyway |
simon | 1:fe7ccd3480e6 | 77 | _ncs = 1; |
simon | 1:fe7ccd3480e6 | 78 | |
simon | 1:fe7ccd3480e6 | 79 | // Write to CTRL_REG3 |
simon | 1:fe7ccd3480e6 | 80 | _ncs = 0; |
simon | 1:fe7ccd3480e6 | 81 | _spi.write(LIS302_WRITE | LIS302_CTRL_REG3); |
simon | 1:fe7ccd3480e6 | 82 | _spi.write (0x0); // This is default anyway |
simon | 1:fe7ccd3480e6 | 83 | _ncs = 1; |
simon | 1:fe7ccd3480e6 | 84 | |
simon | 1:fe7ccd3480e6 | 85 | range(0); |
simon | 1:fe7ccd3480e6 | 86 | calibrate(); |
simon | 1:fe7ccd3480e6 | 87 | } |
simon | 1:fe7ccd3480e6 | 88 | |
simon | 1:fe7ccd3480e6 | 89 | float LIS302::x() { |
simon | 1:fe7ccd3480e6 | 90 | // wait for a new sample |
simon | 1:fe7ccd3480e6 | 91 | while(!(status() & LIS302_STATUS_X_AVAILABLE)); |
simon | 1:fe7ccd3480e6 | 92 | |
simon | 1:fe7ccd3480e6 | 93 | _ncs = 0; |
simon | 1:fe7ccd3480e6 | 94 | _spi.write(LIS302_READ | LIS302_OUTX); |
simon | 1:fe7ccd3480e6 | 95 | signed char raw = _spi.write(0x00); |
simon | 1:fe7ccd3480e6 | 96 | _ncs = 1; |
simon | 1:fe7ccd3480e6 | 97 | |
simon | 1:fe7ccd3480e6 | 98 | float gradient = (2.0/(_maxx-_minx)); |
simon | 1:fe7ccd3480e6 | 99 | return (gradient*(float)(raw)/_factor)+((-gradient*_maxx)+1); |
simon | 1:fe7ccd3480e6 | 100 | } |
simon | 1:fe7ccd3480e6 | 101 | |
simon | 1:fe7ccd3480e6 | 102 | float LIS302::y() { |
simon | 1:fe7ccd3480e6 | 103 | // wait for a new sample |
simon | 1:fe7ccd3480e6 | 104 | while(!(status() & LIS302_STATUS_Y_AVAILABLE)); |
simon | 1:fe7ccd3480e6 | 105 | |
simon | 1:fe7ccd3480e6 | 106 | _ncs = 0; |
simon | 1:fe7ccd3480e6 | 107 | _spi.write(LIS302_READ | LIS302_OUTY); |
simon | 1:fe7ccd3480e6 | 108 | signed char raw = _spi.write(0x00); |
simon | 1:fe7ccd3480e6 | 109 | _ncs = 1; |
simon | 1:fe7ccd3480e6 | 110 | |
simon | 1:fe7ccd3480e6 | 111 | float gradient = (2.0/(_maxy-_miny)); |
simon | 1:fe7ccd3480e6 | 112 | return (gradient*(float)(raw)/_factor)+((-gradient*_maxy)+1); |
simon | 1:fe7ccd3480e6 | 113 | } |
simon | 1:fe7ccd3480e6 | 114 | |
simon | 1:fe7ccd3480e6 | 115 | float LIS302::z() { |
simon | 1:fe7ccd3480e6 | 116 | // wait for a new sample |
simon | 1:fe7ccd3480e6 | 117 | while(!(status() & LIS302_STATUS_Z_AVAILABLE)); |
simon | 1:fe7ccd3480e6 | 118 | |
simon | 1:fe7ccd3480e6 | 119 | _ncs = 0; |
simon | 1:fe7ccd3480e6 | 120 | _spi.write(LIS302_READ | LIS302_OUTZ); |
simon | 1:fe7ccd3480e6 | 121 | signed char raw = _spi.write(0x00); |
simon | 1:fe7ccd3480e6 | 122 | _ncs = 1; |
simon | 1:fe7ccd3480e6 | 123 | |
simon | 1:fe7ccd3480e6 | 124 | float gradient = (2.0/(_maxz-_minz)); |
simon | 1:fe7ccd3480e6 | 125 | return (gradient*(float)(raw)/_factor)+((-gradient*_maxz)+1); |
simon | 1:fe7ccd3480e6 | 126 | } |
simon | 1:fe7ccd3480e6 | 127 | |
simon | 1:fe7ccd3480e6 | 128 | void LIS302::range(int g) { |
simon | 1:fe7ccd3480e6 | 129 | |
simon | 1:fe7ccd3480e6 | 130 | // fetch the current CRTL_REG1 |
simon | 1:fe7ccd3480e6 | 131 | _ncs = 0; |
simon | 1:fe7ccd3480e6 | 132 | _spi.write(LIS302_READ | LIS302_CTRL_REG1); |
simon | 1:fe7ccd3480e6 | 133 | int value = _spi.write(0x00); |
simon | 1:fe7ccd3480e6 | 134 | _ncs = 1; |
simon | 1:fe7ccd3480e6 | 135 | |
simon | 1:fe7ccd3480e6 | 136 | // set the range bit, and the calculation factor |
simon | 1:fe7ccd3480e6 | 137 | if(g) { |
simon | 1:fe7ccd3480e6 | 138 | value |= 0x20; // 8g |
simon | 1:fe7ccd3480e6 | 139 | _factor = FACTOR_8g; |
simon | 1:fe7ccd3480e6 | 140 | } else { |
simon | 1:fe7ccd3480e6 | 141 | value &= ~0x20; // 2g |
simon | 1:fe7ccd3480e6 | 142 | _factor = FACTOR_2g; |
simon | 1:fe7ccd3480e6 | 143 | } |
simon | 1:fe7ccd3480e6 | 144 | |
simon | 1:fe7ccd3480e6 | 145 | _ncs = 0; |
simon | 1:fe7ccd3480e6 | 146 | _spi.write(LIS302_WRITE | LIS302_CTRL_REG1); |
simon | 1:fe7ccd3480e6 | 147 | _spi.write(value); |
simon | 1:fe7ccd3480e6 | 148 | _ncs = 1; |
simon | 1:fe7ccd3480e6 | 149 | } |
simon | 1:fe7ccd3480e6 | 150 | |
simon | 1:fe7ccd3480e6 | 151 | void LIS302::calibrate(float maxx, float minx, float maxy, float miny, float maxz, float minz) { |
simon | 1:fe7ccd3480e6 | 152 | _maxx = maxx; |
simon | 1:fe7ccd3480e6 | 153 | _minx = minx; |
simon | 1:fe7ccd3480e6 | 154 | _maxy = maxy; |
simon | 1:fe7ccd3480e6 | 155 | _miny = miny; |
simon | 1:fe7ccd3480e6 | 156 | _maxz = maxz; |
simon | 1:fe7ccd3480e6 | 157 | _minz = minz; |
simon | 1:fe7ccd3480e6 | 158 | } |
simon | 1:fe7ccd3480e6 | 159 | |
simon | 1:fe7ccd3480e6 | 160 | int LIS302::whoami() { |
simon | 1:fe7ccd3480e6 | 161 | _ncs = 0; |
simon | 1:fe7ccd3480e6 | 162 | _spi.write(LIS302_READ | LIS302_WHOAMI); |
simon | 1:fe7ccd3480e6 | 163 | int value = _spi.write(0x00); |
simon | 1:fe7ccd3480e6 | 164 | _ncs = 1; |
simon | 1:fe7ccd3480e6 | 165 | return value; |
simon | 1:fe7ccd3480e6 | 166 | } |
simon | 1:fe7ccd3480e6 | 167 | |
simon | 1:fe7ccd3480e6 | 168 | int LIS302::status() { |
simon | 1:fe7ccd3480e6 | 169 | _ncs = 0; |
simon | 1:fe7ccd3480e6 | 170 | _spi.write(0xA7); |
simon | 1:fe7ccd3480e6 | 171 | int value = _spi.write(LIS302_READ | LIS302_STATUS_REG); |
simon | 1:fe7ccd3480e6 | 172 | _ncs = 1; |
simon | 1:fe7ccd3480e6 | 173 | return value; |
simon | 1:fe7ccd3480e6 | 174 | } |