Guido Ottaviani
A porting of a GPS decoding and presenting program within the mbos RTOS. It is not a definitive application but a study program to test NMEA full decoding library and a first approach to an RTOS. Many thanks to Andrew Levido for his support and his patience on teaching me the RTOS principles from the other side of the Earth. It uses NMEA library by Tim (xtimor@gmail.com) ported by Ken Todotani (http://mbed.org/users/todotani/) on public mbed library (http://mbed.org/users/todotani/programs/GPS_nmeaLib/5yo4h) also available, as original universal C library, on http://nmea.sourceforge.net
Dependencies: mbos Watchdog TextLCD mbed ConfigFile
Diff: Task2Keypad.cpp
- Revision:
- 2:8917036cbf69
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/Task2Keypad.cpp Tue Jan 31 00:22:58 2012 +0000
@@ -0,0 +1,105 @@
+#include "Task2Keypad.h"
+
+void KeypadTask(void)
+{/**
+ *\brief TASK 2, Keypad management.
+ It uses just one ADC port. Five keys switch a 5 resistor ladder
+ obtaining a unique voltage for each key, with a priority that
+ depends from the position of the resistor in the ladder.
+ This function makes an average of 50 analog values (50ms) before
+ confirming the output, to filter out some noise and debounce keys
+ */
+
+ static float KeypadAcc; // accumulator to compute average
+ static float KeypadPrev; // previous value to compute variation
+ static int KeypadCount; // all samples number
+ static int KeypadRealCount; // valid samples only
+ float KeypadVal;
+ static char KeyPrev='-';
+
+ os.SetTimer(KEYPAD_TMR, 1, 1);
+ while(1)
+ {
+ os.WaitEvent(KEYPAD_EVT);
+ float InValue = KeypadIn.read();
+ if ((InValue > 0.3) && (abs(InValue - KeypadPrev) < 0.1))
+ {// makes the average only of the values above a threshold
+ // and within an almost stable range
+ KeypadAcc+=InValue;
+ KeypadRealCount++;
+ }
+
+ KeypadCount++;
+ KeypadPrev=InValue;
+
+ if (KeypadCount >=50)
+ {
+ if(KeypadRealCount > 25)
+ {
+ KeypadVal=KeypadAcc/KeypadRealCount;
+ }
+ else
+ {// not enough values to average
+
+ KeypadVal=0;
+ }
+
+ KeypadAcc=0;
+ KeypadCount=0;
+ KeypadRealCount=0;
+
+ if(KeypadVal <0.15)
+ {
+ Key='-';
+ }
+ else if(KeypadVal>=0.3 && KeypadVal<0.35)
+ {
+ Key='E';
+ }
+ else if(KeypadVal>=0.42 && KeypadVal<0.50)
+ {
+ Key='v';
+ }
+ else if(KeypadVal>=0.60 && KeypadVal<0.65)
+ {
+ Key='^';
+ }
+ else if(KeypadVal>=0.74 && KeypadVal<0.78)
+ {
+ Key='>';
+ }
+ else if(KeypadVal>=0.85)
+ {
+ Key='<';
+ }
+
+ if (Key!='-' && Key!=KeyPrev)
+ {// switch on the LCD backlight if key pressed
+ os.SetEvent(LCD_LIGHT_DIM_ON_EVT, LCD_LIGHT_DIM_TASK);
+ }
+ KeyPrev=Key;
+ switch (Key)
+ {
+ case '^':
+ Menu=0;
+ break;
+
+ case '>':
+ Menu=1;
+ break;
+
+ case 'v':
+ Menu=2;
+ break;
+
+ case '<':
+ Menu=3;
+ break;
+
+ case 'E':
+ Menu=4;
+ break;
+ }
+ }
+ }
+}