Revision 1:fe7ccd3480e6, committed 2010-06-08

Comitter:

simon

Date:

Tue Jun 08 13:34:48 2010 +0000

Parent:

0:0785e0c655e0

Commit message:

Changed in this revision

diff -r 0785e0c655e0 -r fe7ccd3480e6 LIS302.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LIS302.cpp	Tue Jun 08 13:34:48 2010 +0000
@@ -0,0 +1,174 @@
+/* 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;
+}

diff -r 0785e0c655e0 -r fe7ccd3480e6 LIS302.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LIS302.h	Tue Jun 08 13:34:48 2010 +0000
@@ -0,0 +1,105 @@
+/* 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.
+ */
+
+#ifndef MBED_LIS302_H
+#define MBED_LIS302_H
+ 
+#include "mbed.h"
+
+/** An interface for the LIS302 triple axis SPI accelerometer
+ *
+ * @code
+ * // Print out the Z axis acceleration
+ * #include "mbed.h"
+ * #include "LIS302.h"
+ * 
+ * LIS302 acc(p5, p6, p7, p8); // mosi, miso, clk, ncs
+ * 
+ * int main() {
+ *     while(1) {
+ *         printf("Z axis acceleration = %.2f\n", acc.z());
+ *         wait(0.1);              
+ *     }
+ * }
+ * @endcode
+ */
+class LIS302  {
+public:
+
+    /** Create an LIS302 interface, connected to the specified pins
+     *
+     * @param mosi SPI data out
+     * @param miso SPI data in
+     * @param clk  SPI clock
+     * @param ncs Active low chip select (DigitalOut)
+     */
+    LIS302(PinName mosi, PinName miso, PinName clk, PinName ncs);
+
+    /** Read the X axis acceleration
+     *
+     * @return A floating-point value representing acceleration in g
+     */    
+    float x();
+
+    /** Read the Y axis acceleration
+     *
+     * @return A floating-point value representing acceleration in g
+     */    
+    float y();
+
+    /** Read the Z axis acceleration
+     *
+     * @return - A floating-point value representing acceleration in g
+     */    
+    float z();
+
+    /** Select the range of the accelerometer
+     *
+     * @param range 0 = 2g, 1 = 8g
+     */        
+    void range(int g);
+
+    /** Configure the minima and maxima for the axes to linearise the readings
+     *
+     * @param maxx float defining the maximum X value
+     * @param minx float defining the minimum X value
+     * @param maxy float defining the maximum Y value
+     * @param miny float defining the minimum Y value
+     * @param maxz float defining the maximum Z value
+     * @param minz float defining the minimum Z value
+     */        
+    void calibrate(float maxx = 1, float minx = -1, float maxy = 1, float miny = -1, float maxz = 1, float minz = -1);
+    
+private:
+    SPI _spi;
+    DigitalOut _ncs;    
+
+    int whoami();
+    int status();
+    
+    float _factor;
+    float _maxx, _minx;
+    float _maxy, _miny;
+    float _maxz, _minz;        
+};
+
+#endif

diff -r 0785e0c655e0 -r fe7ccd3480e6 main.cpp
--- a/main.cpp	Fri Nov 13 00:02:35 2009 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,13 +0,0 @@
-// LIS302 Hello World!
-
-#include "mbed.h"
-#include "LIS302.h"
-
-LIS302 acc(p5, p6, p7, p8); // mosi, miso, sclk, ncs
-
-int main() {
-    while(1) {
-        printf("%.3f %.3f %.3f\n", acc.x(), acc.y(), acc.z());
-        wait(0.1);
-    }
-}

diff -r 0785e0c655e0 -r fe7ccd3480e6 mbed.bld
--- a/mbed.bld	Fri Nov 13 00:02:35 2009 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1 +0,0 @@
-http://mbed.org/users/mbed_official/code/mbed/builds/737756e0b479