main.cpp

00001 /*******************************************************************************
00002 
00003   filename  ::  main.cpp
00004   ======================
00005 
00006  Description
00007     Assignment 3 of the B31DG Embedded Software Course.
00008     It consists in writing a simple microcontroller based on the MBED RTOS
00009     library for the LPC1768 board. The repetitive tasks have been implemented
00010     by using RTOS Timers, 4 to be specific. One for the car simulator, one
00011     launching tasks whose frequency is either 5 Hz or 10 Hz, one launching
00012     tasks whose frequency is either 2 Hz, 1 Hz or 0.5 Hz and the last one
00013     is launching tasks running at a frequency of 0.2 Hz and 0.5Hz.
00014 
00015  Version
00016     Antoine    V1.3    February 2018
00017 
00018  History
00019     v1.2        Wrote documentation     
00020     v1.1        Added timers calling tasks multiple of their execution frequency
00021     v1.0        First Complete Version (all tasks done and 11 Timers)
00022     ...
00023     v0.2        Build main structure of program
00024     v0.1        Initial Version
00025     ........................................................................
00026 
00027  Detailed Description
00028     11 tasks were to be performed:
00029         - SIMULATOR - 20 Hz
00030             Write a simple car simulator which will compute the car speed based
00031             on the values of the accelerator (%), the brake (%) and the state
00032             of the engine.
00033         - TASK 1    - 10 Hz
00034             Read the value of 2 analog inputs which correspond to the values of
00035             acceleration and brake.
00036         - TASK 2    - 2 Hz
00037             Read a digital input switch corresponding to the state of the engine
00038         - TASK 3    - 5 Hz
00039             Filter the speed with an averaging filter.
00040         - TASK 4    - 2 Hz
00041             Show the use of a brake with a digital output
00042         - TASK 5    - 1 Hz
00043             Monitor the speed, and if it goes above a given threshold, switch on
00044             a digital output
00045         - TASK 6    - 2 Hz
00046             Display on the screen travelled distance & the last average speed
00047         - TASK 7    - 0.2 Hz
00048             Send into a MAIL queue object the values of speed, accelerometer and
00049             brake. The queue has a size of 100.
00050         - TASK 8    - 0.05 Hz
00051             Dump the the content of the queue into the serial port.
00052         - TASK 9    - 1 Hz
00053             Read a digital switch and set a digital output based on its state
00054         - TASK 10   - 0.5 Hz
00055             Read two switches and set two LEDs according to their state. They
00056             blink at 1 Hz if only one of the switch is on, at 2 Hz is they
00057             are both on.
00058             
00059     .........................................................................
00060     
00061  Personnal Values           None
00062     ..............................
00063 
00064  Method
00065     I decided not to use global variables between the different functions called
00066     by the RTOS timer as a challenge and because it is not safe to use global
00067     variables in most of the case because you lose control on the origin of
00068     a modification on them.
00069     Hence, I declared a structure which is used by the different tasks and
00070     contains pointers to every variables, structures or object needed.
00071     To make it work, I had to slightly modify the RTOSTimer library and remove
00072     the 'const' keyword protecting the given pointer to function calls.
00073  
00074     The functions used by for the different task execution are located in the
00075     included files "my_tasks" while "my_tools" contains functions called by the 
00076     tasks in order to simplify their code.
00077     
00078     The header "my_stucture" contains 3 small structures:
00079         - engineRAWValues which stores the RAW values of the car
00080         - carStatistics which stores values about speed and distance
00081         - mailStruct which is the structure required by the mail Queue object    
00082 
00083     ..........................................................................
00084 
00085 
00086 
00087 *******************************************************************************/
00088 
00089 
00090 #include "mbed.h"
00091 #include "rtos.h"
00092 #include "my_tools.h"
00093 #include "my_structures.h"
00094 #include "my_tasks.h"
00095 
00096 #define     BACK_LIGHT_ON(INTERFACE)    INTERFACE->write_bit(ON,BL_BIT)
00097 #define     BACK_LIGHT_OFF(INTERFACE)   INTERFACE->write_bit(OFF,BL_BIT)
00098 
00099 /*******************************************************************************
00100  *                            PIN DECLARATION
00101  ******************************************************************************/
00102 #define     ANALOG_INPUT_1              p20
00103 #define     ANALOG_INPUT_2              p18
00104 
00105 #define     DIGITAL_IN_ENGINE           p15
00106 #define     DIGITAL_IN_SIDE             p16
00107 #define     DIGITAL_IN_LEFT             p11
00108 #define     DIGITAL_IN_RIGHT            p14
00109 
00110 #define     DIGITAL_OUT_OVERSPEED       p26
00111 #define     DIGITAL_OUT_BRAKE           p25
00112 
00113 using namespace std;
00114 
00115 // ===============
00116 //  System Inputs 
00117 // ===============
00118 AnalogIn    ACCELERATOR(ANALOG_INPUT_1);
00119 AnalogIn    BRAKE(ANALOG_INPUT_2);
00120 DigitalIn   ENGINE_SWITCH(DIGITAL_IN_ENGINE);
00121 DigitalIn   SIDE_LIGHT_SWITCH(DIGITAL_IN_SIDE);
00122 DigitalIn   LEFT_SWITCH(DIGITAL_IN_LEFT);
00123 DigitalIn   RIGHT_SWITCH(DIGITAL_IN_RIGHT);
00124 
00125 // ================
00126 //  System Outputs
00127 // ================
00128 DigitalOut  SIDE_LIGHT_INDICATOR(LED1);
00129 PwmOut      LEFT_LIGHT(LED2);
00130 PwmOut      RIGHT_LIGHT(LED3);
00131 DigitalOut  ENGINE_LIGHT(LED4);
00132 DigitalOut  OVERSPEED_LIGHT(DIGITAL_OUT_OVERSPEED);
00133 DigitalOut  BRAKE_LIGHT(DIGITAL_OUT_BRAKE);
00134 
00135 /*******************************************************************************
00136  *                          FUNCTION PROTOTYPES
00137  ******************************************************************************/
00138 
00139 /** Initialize the main structure used in the program
00140  *
00141  *  @param: Set a arguments used to initalize the structure, all pointers
00142  */
00143 void initializeStructure(carStructure           &car, 
00144                          engineRAWValues        *rawValues,
00145                          carStatistics          *carStat,
00146                          Mail<mailStruct,100>   *mailQueue,
00147                          Mutex                  *rawMutex, 
00148                          Mutex                  *speedMutex,
00149                          Mutex                  *mailMutex,
00150                          MCP23017               *par_port,
00151                          WattBob_TextLCD        *lcd,
00152                          Serial                 *pcSerial
00153                         );
00154 
00155 /*******************************************************************************
00156  *                              MAIN FUNCTION
00157  ******************************************************************************/
00158 int main()
00159 {
00160     /****************************
00161      *       MAIN SETUP
00162      ****************************/
00163     // ---------------------------------------------------------------------- //
00164     // Screen Variables
00165     MCP23017            *par_port;
00166     WattBob_TextLCD     *lcd;
00167     par_port = new MCP23017(p9, p10, 0x40);     // initialise 16-bit I/O chip
00168     lcd      = new WattBob_TextLCD(par_port);   // initialise 2*26 char display
00169     
00170     // Turn LCD backlight ON
00171     par_port->write_bit(ON,BL_BIT);
00172     
00173     // Init Message on Screen
00174     lcd->cls();
00175     lcd->locate(0,0);
00176     lcd->printf("Init...");
00177     wait(0.5);
00178     
00179     
00180     // ---------------------------------------------------------------------- //
00181     // USB Connection to PC
00182     Serial PCSerial(USBTX,USBRX);
00183     // Increase Baud Rate of Serial Connection
00184     PCSerial.baud(115200);
00185     
00186     /****************************
00187      *   DECLARE STRUCTURES
00188      ****************************/ 
00189     // ---------------------------------------------------------------------- //
00190     // ENGINE RAW VALUES   
00191     Mutex           rawMutex;
00192     engineRAWValues rawValues;
00193     initRAWValuesStruct(rawValues);
00194     // ---------------------------------------------------------------------- //
00195     // CAR STATISTICS VALUES
00196     vector<float>   speedVec(SIZE_SPEED_VECTOR);
00197     Mutex           speedMutex;
00198     carStatistics   carStats;
00199     initCarStatisticsStruct(carStats, &speedVec);
00200 
00201     // ---------------------------------------------------------------------- //
00202     // MAIL QUEUE STRUCTURE
00203     Mail<mailStruct,100> mailQueue;
00204     Mutex                mailMutex;
00205     
00206     // ---------------------------------------------------------------------- //
00207     // Declare structure to be used by the different task functions
00208     carStructure myCar;
00209     initializeStructure(myCar, 
00210                         &rawValues, &carStats, 
00211                         &mailQueue,
00212                         &rawMutex, &speedMutex, &mailMutex,
00213                         par_port, lcd,
00214                         &PCSerial
00215                        );
00216 
00217     // ---------------------------------------------------------------------- //
00218     // ---------------------------------------------------------------------- //
00219     /****************************
00220      *   DECLARE RTOS TIMER
00221      ****************************/
00222     RtosTimer carSimulator(task0_carSim,    osTimerPeriodic, (void *) &myCar);
00223     RtosTimer timer_1(timer1, osTimerPeriodic, (void *) &myCar);
00224     RtosTimer timer_2(timer2, osTimerPeriodic, (void *) &myCar);
00225     RtosTimer timer_3(timer3, osTimerPeriodic, (void *) &myCar);
00226     
00227 
00228     /****************************
00229     *     START RTOS TIMER
00230     ****************************/
00231     carSimulator.start(50); // 20Hz
00232     timer_1.start(100);     // 10 Hz
00233     timer_2.start(500);     // 2 Hz
00234     timer_3.start(5000);    // 0.2 Hz
00235     
00236     // RtosTimer will run forever
00237     Thread::wait(osWaitForever);
00238 
00239     return 0;
00240 }
00241 
00242 
00243 void initializeStructure(carStructure           &car, 
00244                          engineRAWValues        *rawValues,
00245                          carStatistics          *carStat,
00246                          Mail<mailStruct,100>   *mailQueue,
00247                          Mutex                  *rawMutex, 
00248                          Mutex                  *speedMutex,
00249                          Mutex                  *mailMutex,
00250                          MCP23017               *par_port,
00251                          WattBob_TextLCD        *lcd,
00252                          Serial                 *pcSerial
00253                         )
00254 {
00255     //  System Inputs 
00256     car.p_accelerator         = &ACCELERATOR ;
00257     car.p_brake               = &BRAKE ;
00258     car.p_engineSwitch        = &ENGINE_SWITCH ;
00259     car.p_sideLightSwitch     = &SIDE_LIGHT_SWITCH ;
00260     car.p_leftSwitch          = &LEFT_SWITCH ;
00261     car.p_rightSwitch         = &RIGHT_SWITCH ;
00262     
00263     //  System Outputs
00264     car.p_sideLightIndicator  = &SIDE_LIGHT_INDICATOR ;
00265     car.p_leftLight           = &LEFT_LIGHT ;
00266     car.p_rightLight          = &RIGHT_LIGHT ;
00267     car.p_engineLight         = &ENGINE_LIGHT ;
00268     car.p_overspeedLight      = &OVERSPEED_LIGHT ;
00269     car.p_brakeLight          = &BRAKE_LIGHT ;
00270     
00271     // Values Structure;
00272     car.p_rawValues          = rawValues;
00273     car.p_carStats           = carStat;
00274     car.p_mailQueue          = mailQueue;
00275     car.nbElementInQueue     = 0;
00276     
00277     // Mutex
00278     car.p_rawMutex           = rawMutex;
00279     car.p_statMutex          = speedMutex;
00280     car.p_mailMutex          = mailMutex;
00281     
00282     // Serial Connection
00283     car.p_PC                 = pcSerial;
00284     
00285     // Screen variables
00286     car.p_par_port           = par_port;
00287     car.p_lcd                = lcd;
00288 }