Serial Port Help

Mbed OS
1

my friend and i have written a program for a LED game which starts if certain conditions are met by the color and distance sensor. we have to interface this game with the help of visual studio, windows forms using serial ports… i want to edit my code in such a way that when i press the close button on windows forms, the game stops and remains halted till i give it the command to start again. the code on mbed is shown below

#include "mbed.h"
#include "DebounceIn.h"
#include "stdint.h"
#include "MCP23017.h"
#include "WattBob_TextLCD.h"
#include "VL6180.h"
#include "TCS3472_I2C.h"

#define     BACK_LIGHT_ON(INTERFACE)    INTERFACE->write_bit(1,BL_BIT)
#define     BACK_LIGHT_OFF(INTERFACE)   INTERFACE->write_bit(0,BL_BIT)

MCP23017            *par_port;
WattBob_TextLCD     *lcd;

#define IDENTIFICATIONMODEL_ID 0x0000

Serial PC(USBTX, USBRX); //default 9600 baud
VL6180  TOF_sensor(p28, p27);
TCS3472_I2C rgb_sensor(p9, p10);

DigitalOut myled1 (p13);    DigitalOut myled2 (p14);
DigitalOut myled3 (p15);    DigitalOut myled4 (p16);

DebounceIn pb1(p17);    DebounceIn pb2(p18);
DebounceIn pb3(p19);    DebounceIn pb4(p20);

int old_pb1 = 0, old_pb2 = 0, old_pb3 = 0, old_pb4 = 0;
int new_pb1,     new_pb2,     new_pb3,     new_pb4;

int i = 0, col, row, led; //variables for order manipulation
int levelreset, tries, level = 1; //level parameters
float delay; //delay for blinking LEDs
int D = 30; //for distance sensor

int order[24][4] = //ORDER ARRAY FOR LED GAME
{1,2,3,4,   2,1,3,4,    3,1,2,4,    1,3,2,4,    2,3,1,4,    3,2,1,4,
 4,2,1,3,   2,4,1,3,    1,4,2,3,    4,1,2,3,    2,1,4,3,    1,2,4,3,
 1,3,4,2,   3,1,4,2,    4,1,3,2,    1,4,3,2,    3,4,1,2,    4,3,1,2,
 4,3,2,1,   3,4,2,1,    2,4,3,1,    4,2,3,1,    3,2,4,1,    2,3,4,1};

void LEDgame(); //function prototype of LED game
void reset(); //to reset level
void light(int); //turn on LEDs
void Maint(); // maintainence mode
int Dist(); //check distance sensor
int MAX(int,int,int); //find max rgb value

int main()

{
    pb1.mode(PullUp);   pb2.mode(PullUp);
    pb3.mode(PullUp);   pb4.mode(PullUp);
    wait(.001);
    
    par_port = new MCP23017(p9, p10, 0x40);
    par_port->config(0x0F00, 0x0F00, 0x0F00);           //configure MCP23017 chip on WattBob
    lcd = new WattBob_TextLCD(par_port);
    BACK_LIGHT_ON(par_port);
    
    TOF_sensor.VL6180_Init();
    rgb_sensor.enablePowerAndRGBC();
    rgb_sensor.setIntegrationTime(100);
    
    int rgb_read[4], maxrgb;
    char c = PC.getc();
    if (c == 'o'){
    while(1)
    {
        rgb_sensor.getAllColors(rgb_read);
        maxrgb = MAX(rgb_read[1],rgb_read[2],rgb_read[3]);
        if (maxrgb == rgb_read[1])
        //if (maxrgb > 2000 && maxrgb < 3000)
        while(level <= 4 && Dist() < D)
        {
            if (level == 0) break; //to stop game if level reset to zero.
            row = rand()%24;
            tries = 1;
            LEDgame();
        }
        if (Dist() > D) {
            level = 1;
            myled1=0; myled2=0; myled3=0; myled4=0;
            } //resets game if card is removed.
    }
}
}



void LEDgame()
{
    while(Dist() < D)
    {
        levelreset = 0;
        for (col=0; col<4; col++)
        {led = order[row][col]; light(led);} //switches on the respective LEDs according to the order

    while(Dist() < D)
    {
        new_pb1 = pb1; new_pb2 = pb2;
        new_pb3 = pb3; new_pb4 = pb4;
        
    if( ((new_pb1 == 0) && (old_pb1 == 1)) || ((new_pb2 == 0) && (old_pb2 == 1)) || ((new_pb3 == 0) && (old_pb3 == 1)) || ((new_pb4 == 0) && (old_pb4 == 1)) )
    {
        switch(order[row][i])
        {
            case 1:
            {
                if((new_pb1 == 0) && (old_pb1 == 1))
                { myled1 = 1; i++;}
                else {reset(); levelreset = 1; tries++;}
            } break;
            case 2:
            {
                if((new_pb2 == 0) && (old_pb2 == 1))
                { myled2 = 1; i++;}
                else {reset(); levelreset = 1; tries++;}
            } break;
            case 3:
            {
                if((new_pb3 == 0) && (old_pb3 == 1))
                { myled3 = 1; i++;}
                else {reset(); levelreset = 1; tries++;}
            } break;
            case 4:
            {
                if((new_pb4 == 0) && (old_pb4 == 1))
                { myled4 = 1; i++;}
                else {reset(); levelreset = 1; tries++;}
            } break;
        }
        if (levelreset == 1) //do if the level was reset during the game
        {
            //reset level to zero to stop game if number of tries exceeded
            if (tries > 3) {level = 0; reset(); return;}
            else break;
        }
        else if (levelreset == 0) //else increment level counter
            if(i >= 4){level++; wait(2); reset(); return;}
    }
        old_pb1 = new_pb1; old_pb2 = new_pb2;
        old_pb3 = new_pb3; old_pb4 = new_pb4;
    }
    }
}



void reset() //function to turn off LEDs and reset order
{
    myled1 = 0; myled2 = 0; myled3 = 0; myled4 = 0;
    i = 0; wait(1); return;
}

void light(int n) //to turn on LEDs
{
    //sets delay based on level number
    if(level == 1) delay = 1;
    else if (level == 2) delay = 0.75;
    else if (level == 3) delay = 0.50;
    else if (level == 4) delay = 0.25;
    
    //turns LED on for delay seconds before turning off
    if(n == 1) {myled1 = 1; wait(delay); myled1 = 0;}
    else if(n == 2) {myled2 = 1; wait(delay); myled2 = 0;}
    else if(n == 3) {myled3 = 1; wait(delay); myled3 = 0;}
    else if(n == 4) {myled4 = 1; wait(delay); myled4 = 0;}
    return;
}

int Dist() //returns distance
{
    uint8_t dist;
    lcd->cls(); lcd->locate(0,0);
    dist = TOF_sensor.getDistance();
    lcd->printf("Dist=%d", dist);
    return dist;
}

int MAX(int R, int G, int B) //returns max rgb value
{
    int max;
    if (R > G) max = R;
    else max = G;
    if (B > max) max = B;
    return max;
}
2

For your information, you can make code blocks by placing triple backticks before and after your code. It makes it easier to read.

```
// your code starts after triple backticks
#include “mbed.h”
#include “DebounceIn.h”
#include “stdint.h”
#include “MCP23017.h”
#include “WattBob_TextLCD.h”
#include “VL6180.h”
#include “TCS3472_I2C.h”

#define BACK_LIGHT_ON(INTERFACE) INTERFACE->write_bit(1,BL_BIT)
#define BACK_LIGHT_OFF(INTERFACE) INTERFACE->write_bit(0,BL_BIT)
// .....
// close the code block with triple backticks
```
3

done. thank you for the tip!

4

I understand you want to pause and play whatever happening in the while loop in main(). I would use interrupt. This simple example below pauses and restarts LED blinking. The serial interrupt function toggles a flag called playing and LED pauses if playing is false.

DigitalOut led(LED1);
RawSerial pc(USBTX, USBRX);
volatile bool playing = true; // this has to be volatile as it is modified in ISR context.

void onDataReceived() {
    char c = pc.getc();
    playing = (c == 's') ? false : true;
}

int main() {
    pc.attach(&onDataReceived, Serial::RxIrq); // attach serial interrupt callback
    while (1) {
        while (!playing) {} // wait until playing becomes true
        ThisThread::sleep_for(500);  
        led = !led;
    }
}