Interface for an LIS302 accelerometer, using the SPI interface
Dependents: LIS302_HelloWorld mbed_line_camera
LIS302.cpp
- Committer:
- simon
- Date:
- 2010-06-08
- Revision:
- 1:fe7ccd3480e6
File content as of revision 1:fe7ccd3480e6:
/* mbed LIS302 Accelerometer Library * Copyright (c) 2008-2010, sford, cstyles, wreynolds * * 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 "LIS302.h" #include "mbed.h" #define LIS302_WHOAMI 0x0F #define LIS302_CTRL_REG1 0x20 #define LIS302_CTRL_REG2 0x21 #define LIS302_CTRL_REG3 0x22 #define LIS302_HP_FILTER_RST 0x23 #define LIS302_STATUS_REG 0x27 #define LIS302_OUTX 0x29 #define LIS302_OUTY 0x2B #define LIS302_OUTZ 0x2D #define LIS302_FF_WU_CFG1 0x30 #define LIS302_FF_WU_SRC_1 0x31 #define LIS302_FF_WU_THS_1 0x32 #define LIS302_FF_WU_DURATION_1 0x33 #define LIS302_FF_WU_CFG_2 0x34 #define LIS302_FF_WU_SRC_2 0x35 #define LIS302_FF_WU_THS_2 0x36 #define LIS302_FF_WU_DURATION_2 0x37 #define LIS302_CLICK_CFG 0x38 #define LIS302_CLICK_SRC 0x39 #define LIS302_CLICK_THSY_X 0x3B #define LIS302_CLICK_THSZ 0x3C #define LIS302_READ 0x80 #define LIS302_WRITE 0x00 #define LIS302_STATUS_X_AVAILABLE 0x1 #define LIS302_STATUS_Y_AVAILABLE 0x2 #define LIS302_STATUS_Z_AVAILABLE 0x4 #define FACTOR_2g 55.6 #define FACTOR_8g 13.9 LIS302::LIS302(PinName mosi, PinName miso, PinName clk, PinName ncs) : _spi(mosi, miso, clk), _ncs(ncs) { // Make sure CS is high _ncs = 1; // Set up the spi interface _spi.format(8, 3); _spi.frequency(1000000); // Write to CTRL_REG1 _ncs = 0; _spi.write(LIS302_WRITE | LIS302_CTRL_REG1); _spi.write (0x47); _ncs = 1; // Write to CTRL_REG2 _ncs = 0; _spi.write(LIS302_WRITE | LIS302_CTRL_REG2); _spi.write (0x0); // This is default anyway _ncs = 1; // Write to CTRL_REG3 _ncs = 0; _spi.write(LIS302_WRITE | LIS302_CTRL_REG3); _spi.write (0x0); // This is default anyway _ncs = 1; range(0); calibrate(); } float LIS302::x() { // wait for a new sample while(!(status() & LIS302_STATUS_X_AVAILABLE)); _ncs = 0; _spi.write(LIS302_READ | LIS302_OUTX); signed char raw = _spi.write(0x00); _ncs = 1; float gradient = (2.0/(_maxx-_minx)); return (gradient*(float)(raw)/_factor)+((-gradient*_maxx)+1); } float LIS302::y() { // wait for a new sample while(!(status() & LIS302_STATUS_Y_AVAILABLE)); _ncs = 0; _spi.write(LIS302_READ | LIS302_OUTY); signed char raw = _spi.write(0x00); _ncs = 1; float gradient = (2.0/(_maxy-_miny)); return (gradient*(float)(raw)/_factor)+((-gradient*_maxy)+1); } float LIS302::z() { // wait for a new sample while(!(status() & LIS302_STATUS_Z_AVAILABLE)); _ncs = 0; _spi.write(LIS302_READ | LIS302_OUTZ); signed char raw = _spi.write(0x00); _ncs = 1; float gradient = (2.0/(_maxz-_minz)); return (gradient*(float)(raw)/_factor)+((-gradient*_maxz)+1); } void LIS302::range(int g) { // fetch the current CRTL_REG1 _ncs = 0; _spi.write(LIS302_READ | LIS302_CTRL_REG1); int value = _spi.write(0x00); _ncs = 1; // set the range bit, and the calculation factor if(g) { value |= 0x20; // 8g _factor = FACTOR_8g; } else { value &= ~0x20; // 2g _factor = FACTOR_2g; } _ncs = 0; _spi.write(LIS302_WRITE | LIS302_CTRL_REG1); _spi.write(value); _ncs = 1; } void LIS302::calibrate(float maxx, float minx, float maxy, float miny, float maxz, float minz) { _maxx = maxx; _minx = minx; _maxy = maxy; _miny = miny; _maxz = maxz; _minz = minz; } int LIS302::whoami() { _ncs = 0; _spi.write(LIS302_READ | LIS302_WHOAMI); int value = _spi.write(0x00); _ncs = 1; return value; } int LIS302::status() { _ncs = 0; _spi.write(0xA7); int value = _spi.write(LIS302_READ | LIS302_STATUS_REG); _ncs = 1; return value; }