Revision 2:186e38f0c07e, committed 2011-01-03

Comitter:

jsolarski

Date:

Mon Jan 03 10:13:42 2011 +0000

Parent:

1:a3822b798d67

Commit message:

Added Rate function, the map function in cpp may be missing critical math for the calculation

Changed in this revision

--- a/gyro.cpp	Tue Dec 21 06:09:02 2010 +0000
+++ b/gyro.cpp	Mon Jan 03 10:13:42 2011 +0000
@@ -24,6 +24,12 @@
 #include "mbed.h"
 #include "gyro.h"
 
+long map(long x, long in_min, long in_max, long out_min, long out_max)
+{
+  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
+}
+
+
 Gyro::Gyro(PinName g_pin, PinName st, PinName pd) : _g_pin(g_pin), _st(st), _pd(pd) {
     _st.write(0);
     _pd.write(0);
@@ -41,4 +47,11 @@
 }
 void Gyro::wakeup() {
     _pd.write(0);
-}
\ No newline at end of file
+}
+int Gyro::rate() {
+    unsigned int speed;
+    int mapped;
+    speed = _g_pin.read_u16();
+    mapped = map(speed, 0, 65535, -300, 300);
+    return mapped;
+}

--- a/gyro.h	Tue Dec 21 06:09:02 2010 +0000
+++ b/gyro.h	Mon Jan 03 10:13:42 2011 +0000
@@ -30,6 +30,9 @@
  * Used for reading from an analog Gyro Tested with LISY300Al spark fun breakout board
  * http://www.sparkfun.com/products/8955
  * 300o/S
+ * specs - 3.3mV per o/S +-300 0/S max
+ *       - 5% temp variance 
+ *       - 
  *
  * Example:
  *
@@ -46,6 +49,7 @@
  * @param pd = powerdown
  */
     Gyro (PinName g_pin, PinName st, PinName pd);
+
 /** read gyros analog pin 
  *
  * outputs 0.0-1.0 
@@ -66,8 +70,15 @@
  *
  */
     void wakeup();
+/** give you rate or turning degrees per second Fo/S
+ *  - uses the map funciton defined in the cpp file
+ *  - this function works, but no real world data yet
+ *  - I might be missing some critical math for conversion 
+ */
+    int rate();
+        
+private :
 
-private :
     AnalogIn _g_pin;
     DigitalInOut _st;
     DigitalInOut _pd;