M L
Embedded Software Assignment 3
Dependencies: MCP23017 Servo WattBob_TextLCD mbed-rtos mbed
Fork of
ES_Assignment_3_Pub
by 
M L
Diff: main.cpp
- Revision:
- 1:15edb3b6763a
- Parent:
- 0:6b3496e7a954
--- a/main.cpp Fri May 27 15:56:36 2016 +0000
+++ b/main.cpp Fri May 27 17:02:52 2016 +0000
@@ -11,6 +11,8 @@
For the Display it uses an LCD Screen
For the Speedometer it uses an Servo
The Emulation and Synchronisation is implemented using TimerThreads and Semaphores
+ for the reason of existing thread limits, conventional timers are helping to slicing
+ timeslots
@version 1.4
@updateDate 30.03.2016
@@ -57,7 +59,7 @@
void Timer3_void(void const *args); // Timer 3
-// Task Functions
+ // Task Functions
void task1_break_accelerate();
void task2_read_show_engine_state();
void task3_show_odometer();
@@ -70,6 +72,8 @@
void task10_calc_avg_speed();
void task11_emulate_car();
+
+ // Init Variables
int Convert_Hz_to_Ms(double Hz);
float accerlator(0);
@@ -87,11 +91,12 @@
bool sw_timer11(0);
bool sw_timer2(0);
bool sw_timer21(0);
-int sw_timer3(4); // initalize with a first run
+int sw_timer3(4); // sw_timer3 initalize with a first run
std::deque<float> AvgSpeedDB; // used for storing the average speed
-Semaphore SemAvgSpeedDB(1);
+
+Semaphore SemAvgSpeedDB(1); // declare used Semaphores
Semaphore SemAvgSpeed(1);
Semaphore SemSpeed(1);
Semaphore SemBreak_Accelerate(1);
@@ -127,7 +132,7 @@
lcd->cls(); // clear display
lcd->locate(0,0); // set cursor to location (0,0) - top left corner
- RtosTimer Timer1(Timer1_void,osTimerPeriodic,(void *)NULL);
+ RtosTimer Timer1(Timer1_void,osTimerPeriodic,(void *)NULL); // create the necesarry timers to overcome a thread issue (max threads)
Timer1.start(Convert_Hz_to_Ms(20.0));
RtosTimer Timer2(Timer2_void,osTimerPeriodic,(void *)NULL);
@@ -156,7 +161,7 @@
if(sw_timer1) { // runs just every second time, so at 10 hz
task1_break_accelerate();
sw_timer11 = !sw_timer11;
- if(sw_timer11) { // runs just every second time, so at 5 hz
+ if(sw_timer11) { // runs just every fourth time, so at 5 hz
task10_calc_avg_speed();
}
}
@@ -197,7 +202,7 @@
task8_read_single_side_light();
sw_timer21 = !sw_timer21;
- if (!indicator_R && indicator_L) {
+ if (!indicator_R && indicator_L) { // switch the left / right indicator
DoutLEDRight=0;
DoutLEDLeft=!DoutLEDLeft;
} else if(indicator_R && !indicator_L) {
@@ -226,8 +231,8 @@
{
task6_fill_mail_queue();
if((sw_timer3%4)==0) { // task runs at 0.05 Hz
- task7_dump_mail_to_serial();
- sw_timer3=0;
+ task7_dump_mail_to_serial(); // dump the queue to serial
+ sw_timer3=0; // reset the timer
}
sw_timer3++;
}
@@ -238,9 +243,12 @@
*/
void task1_break_accelerate()
{
+ // Let the Semaphores wait
SemBreak_Accelerate.wait();
- accerlator = AinAccel;
- brake = AinBreak;
+
+ accerlator = AinAccel; // save the accerlator value
+ brake = AinBreak; // save the brake value
+ // Let the Semaphores release
SemBreak_Accelerate.release();
}
@@ -250,9 +258,12 @@
*/
void task2_read_show_engine_state()
{
+ // Let the Semaphores wait
SemEngine.wait();
- engine = DinSwitchEngine;
- DoutLEDEngine = engine;
+
+ engine = DinSwitchEngine; // read the engine state
+ DoutLEDEngine = engine; // write the engine state
+ // Let the Semaphores release
SemEngine.release();
}
@@ -262,8 +273,10 @@
*/
void task3_show_odometer()
{
- SemAvgSpeed.wait();
- Odometer = avgSpeed/250.0;
+ // Let the Semaphores wait
+ SemAvgSpeed.wait();
+ Odometer = avgSpeed/250.0; // Calculate the odometer
+ // Let the Semaphores release
SemAvgSpeed.release();
}
@@ -273,11 +286,13 @@
*/
void task4_speed_warning()
{
+ // Let the Semaphores wait
SemAvgSpeed.wait();
- if(avgSpeed>75.0)
- LEDSpeedWarning = !LEDSpeedWarning;
+ if(avgSpeed>75.0) // check our speed
+ LEDSpeedWarning = !LEDSpeedWarning; // and switch the Warning on/off
else
LEDSpeedWarning = 0;
+ // Let the Semaphores release
SemAvgSpeed.release();
}
@@ -287,7 +302,7 @@
*/
void task5_update_odometer()
{
- // Let the Semaphores wait
+ // Let the Semaphores wait
SemDistance.wait();
SemAvgSpeed.wait();
@@ -295,8 +310,7 @@
lcd->printf("s: %5.0f",avgSpeed);
lcd->locate(1,0);
lcd->printf("d: %5.0f",dist);
-
- // Let the Semaphores release
+ // Let the Semaphores release
SemDistance.release();
SemAvgSpeed.release();
}
@@ -308,19 +322,19 @@
*/
void task6_fill_mail_queue()
{
- // Let the Semaphores wait
+ // Let the Semaphores wait
SemMailCnT.wait();
SemBreak_Accelerate.wait();
SemSpeed.wait();
- mail_t *mail = mail_box.alloc();
- mail->speed = speed;
+ mail_t *mail = mail_box.alloc(); // reserve the space for our new message
+ mail->speed = speed; // fill with values
mail->accel = accerlator;
mail->brake = brake;
- mail_box.put(mail);
+ mail_box.put(mail); // put the new message into the mail queue
mailcounter++;
- // Let the Semaphores release
+ // Let the Semaphores release
SemBreak_Accelerate.release();
SemSpeed.release();
SemMailCnT.release();
@@ -331,7 +345,7 @@
*/
void task7_dump_mail_to_serial()
{
- // Let the Semaphores wait
+ // Let the Semaphores wait
SemMailCnT.wait();
while(mailcounter) { // as long as we got mail
@@ -347,7 +361,7 @@
mailcounter--;
}
- // Release the Semaphores
+ // Release the Semaphores
SemMailCnT.release();
}
@@ -356,7 +370,7 @@
*/
void task8_read_single_side_light()
{
- DoutLEDLight = DinSwitchLight;
+ DoutLEDLight = DinSwitchLight; // Reading the value
}
@@ -365,8 +379,8 @@
*/
void task9_read_indicators()
{
- indicator_R = DinSwitchRindic;
- indicator_L = DinSwitchLindic;
+ indicator_R = DinSwitchRindic; // Reading the value
+ indicator_L = DinSwitchLindic; // Reading the value
}
@@ -376,16 +390,16 @@
void task10_calc_avg_speed()
{
- // Let the Semaphores wait
+ // Let the Semaphores wait
SemAvgSpeed.wait();
SemAvgSpeedDB.wait();
float sum(0);
for(deque<float>::const_iterator i = AvgSpeedDB.begin(); i != AvgSpeedDB.end(); ++i)
- sum+= *i; // calculate the average by iterating over the queue
+ sum+= *i; // calculate the average by iterating over the queue
avgSpeed = sum/AvgSpeedDB.size();
- // Release the Semaphores
+ // Release the Semaphores
SemAvgSpeedDB.release();
SemAvgSpeed.release();
}
@@ -396,7 +410,7 @@
*/
void task11_emulate_car()
{
- // Let the Semaphores wait
+ // Let the Semaphores wait
SemAvgSpeed.wait();
SemAvgSpeedDB.wait();
SemDistance.wait();
@@ -404,19 +418,19 @@
SemSpeed.wait();
SemEngine.wait();
- if(accerlator<=brake || !engine)
+ if(accerlator<=brake || !engine) // are we braking more than accelerating? is the engine on?
speed = 0;
else
speed = (accerlator-brake) *0.5 +speed;
if(speed>250)
- speed=250; //maximum speed
- if(AvgSpeedDB.size()>=4) // if we already got 4 values, we have to
- AvgSpeedDB.pop_front(); // make space by deleting the oldest value
- AvgSpeedDB.push_back(speed); // safe a new reading
+ speed=250; // maximum speed
+ if(AvgSpeedDB.size()>=4) // if we already got 4 values, we have to
+ AvgSpeedDB.pop_front(); // make space by deleting the oldest value
+ AvgSpeedDB.push_back(speed); // safe a new reading
- dist += speed * 1.0/20.0; // runs at 20 Hz so we have to take this into account
+ dist += speed * 1.0/20.0; // runs at 20 Hz so we have to take this into account
- // Release the Semaphores
+ // Release the Semaphores
SemDistance.release();
SemAvgSpeed.release();
SemAvgSpeedDB.release();