Diff: MMA8452.cpp

Revision:

0:bcf2aa85d7f9

Child:

1:ef026bf28798

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MMA8452.cpp	Fri Oct 04 14:48:02 2013 +0000
@@ -0,0 +1,193 @@
+// Author: Nicholas Herriot
+/* Copyright (c) 2013 Vodafone, MIT License
+ *
+ * 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 "MMA8452.h"
+
+
+
+float TILT_XY[64] = {0, 2.69, 5.38, 8.08, 10.81, 13.55, 16.33, 19.16, 22.02, 24.95, 27.95, 31.04, 34.23, 37.54, 41.01, 44.68, 48.59, 52.83, 57.54, 62.95, 69.64, 79.86, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -79.86, -69.64, -62.95, -57.54, -52.83, -48.59, -44.68, -41.01, -37.54, -34.23, -31.04, -27.95, -24.95, -22.02, -19.16, -16.33, -13.55, -10.81, -8.08, -5.38, -2.69}; 
+float TILT_Z[64] = {90.00, 87.31, 84.62, 81.92, 79.19, 76.45, 73.67, 70.84, 67.98, 65.05, 62.05, 58.96, 55.77, 52.46, 48.99, 45.32, 41.41, 37.17, 32.46, 27.05, 20.36, 10.14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10.14, -20.36, -27.05, -32.46, -37.17, -41.41, -45.32, -48.99, -52.46, -55.77, -58.96, -62.05, -65.05, -67.98, -70.84, -73.67, -76.45, -79.19, -81.92, -84.62};
+
+
+
+// Connect module at I2C address using I2C port pins sda and scl
+Accelerometer_MMA8452::Accelerometer_MMA8452(PinName sda, PinName scl,int frequency) : m_i2c(sda, scl): m_frequency(frequency):
+{
+    //m_i2c.frequency(m_frequency);
+}
+
+
+// Destroys instance
+Accelerometer_MMA8452::~Accelerometer_MMA8452()
+{
+
+}
+
+// Setting the control register bit 1 to true to activate the MMA8452
+int Accelerometer_MMA8452::activate()
+{
+    char mcu_address = (MMA8452_ADDRESS <1);
+    char init[2];
+    init[0] = CTRL_REG_1;                 // control register 1
+    init[1] = 0x01;                       // set to active
+    if(m_i2c.write(mcu_address,init,2) == 0)
+    {
+         // pc.printf("The initialisation worked");
+         return 0;
+    }
+    else
+    {
+        // pc.printf("The initialisation failed");
+        return 1;
+    }
+         
+}
+
+
+// Device initialization
+void Accelerometer_MMA8452::init()
+{
+    
+    write_reg(INTSU_STATUS, 0x10);      // automatic interrupt after every measurement
+    write_reg(SR_STATUS, 0x00);         // 120 Samples/Second
+    write_reg(MODE_STATUS, 0x01);       // Active Mode
+    
+}
+
+
+// Reads the tilt angle
+void Accelerometer_MMA8452::read_Tilt(float *x, float *y, float *z)
+{
+
+    const char Addr_X = OUT_X_MSB;
+    char buf[3] = {0,0,0};
+    
+    m_i2c.write(MMA8452_ADDRESS, &Addr_X, 1);         // Pointer to the OUT_X_MSB register
+    m_i2c.read(MMA8452_ADDRESS, buf, 3);              // Read register content into buffer with 6bit
+    
+    // returns the x, y, z coordinates transformed into full degrees
+    *x = TILT_XY[(int)buf[0]];
+    *y = TILT_XY[(int)buf[1]];
+    *z = TILT_Z[(int)buf[2]];      
+  
+}
+
+
+// Reads x data
+int Accelerometer_MMA8452::read_x()
+{
+    char mcu_address = (MMA8452_ADDRESS <1);
+
+    m_i2c.start();                  // Start
+    m_i2c.write(mcu_address);              // A write to device 0x98
+    m_i2c.write(OUT_X_MSB);             // Register to read
+    m_i2c.start();                  
+    m_i2c.write(mcu_address);              // Read from device 0x99
+    char x = m_i2c.read(0);         // Read the data
+    m_i2c.stop();
+    
+    return (int)x;  
+
+}
+
+
+// Reads y data
+int Accelerometer_MMA8452::read_y()
+{
+    char mcu_address = (MMA8452_ADDRESS <1);
+
+    m_i2c.start();                  // Start
+    m_i2c.write(mcu_address);              // A write to device 0x98
+    m_i2c.write(OUT_Y_MSB);             // Register to read
+    m_i2c.start();                  
+    m_i2c.write(mcu_address);              // Read from device 0x99
+    char y = m_i2c.read(0);         // Read the data
+    m_i2c.stop();
+    
+    return (int)y; 
+
+}
+
+
+// Reads z data
+int Accelerometer_MMA8452::read_z()
+{
+    char mcu_address = (MMA8452_ADDRESS <1);
+    
+    m_i2c.start();                  // Start
+    m_i2c.write(mcu_address);              // A write to device 0x98
+    m_i2c.write(OUT_Z_MSB);             // Register to read
+    m_i2c.start();                  
+    m_i2c.write(mcu_address);              // Read from device 0x99
+    char z = m_i2c.read(0);         // Read the data
+    m_i2c.stop();
+    
+    return (int)z;
+
+}
+
+
+// Reads xyz
+
+
+
+
+        // Write register (The device must be placed in Standby Mode to change the value of the registers) 
+void Accelerometer_MMA8452::write_reg(char addr, char data)
+{
+
+    char cmd[2] = {0, 0};
+    
+    cmd[0] = MODE_STATUS;
+    cmd[1] = 0x00;                      // Standby Mode on
+    m_i2c.write(MMA8452_ADDRESS, cmd, 2);
+  
+    cmd[0] = addr;
+    cmd[1] = data;                      // New value of the register
+    m_i2c.write(MMA8452_ADDRESS, cmd, 2); 
+      
+    cmd[0] = MODE_STATUS;
+    cmd[1] = 0x01;                      // Active Mode on
+    m_i2c.write(MMA8452_ADDRESS, cmd, 2);
+                  
+}
+
+
+
+        // Read from specified MMA7660FC register
+char Accelerometer_MMA8452::read_reg(char addr)
+{
+    
+    m_i2c.start();                  // Start
+    m_i2c.write(0x98);              // A write to device 0x98
+    m_i2c.write(addr);              // Register to read
+    m_i2c.start();                  
+    m_i2c.write(0x99);              // Read from device 0x99
+    char c = m_i2c.read(0);         // Read the data
+    m_i2c.stop();                   
+ 
+    return c;
+    
+}
+
+
+
+
+
+