reading a string from serial port and splitting to integers...

Projects Programming
1

Hi.
I'm using arduino mega2560 for a project that measures some values then prints it on a serial uart LCD.
I want to use the touchscreen of LCD, So i receive a string from serial port No.3 like this: [TP:83,125] that 83 is X of touch point and 125 is Y point.
I'm using the code below:

    if(Serial3.available()) {
   bargasht=Serial3.readString();
   view[0]=bargasht[4];
   view[1]=bargasht[5];
   view[2]=bargasht[6];
   view[3]=bargasht[7];
   view[4]=bargasht[8];
   view[5]=bargasht[9];
   view[6]=bargasht[10];
   converttouchpoint();
      } 

then:


void converttouchpoint(){

  i=0;
  switch(view[i]){
        case '0':
    xtouch[0]=0;
    xflag=1;
    break;
        case '1':
    xtouch[0]=1;
    xflag=1;
    break;
        case '2':
        xflag=1;
    xtouch[0]=2;
    break;
        case '3':
    xtouch[0]=3;
    xflag=1;
    break;
        case '4':
    xtouch[0]=4;
    xflag=1;
    break;
        case '5':
    xtouch[0]=5;
    xflag=1;
    break;
        case '6':
    xtouch[0]=6;
    xflag=1;
    break;
        case '7':
    xtouch[0]=7;
    xflag=1;
    break;
        case '8':
    xtouch[0]=8;
    xflag=1;
    break;
        case '9':
    xtouch[0]=9;
    xflag=1;
    break;
    default:
    xtouch[0]=0;break;}
    i++;
switch(view[i]){
        case',':
        goto ygettouch;
        break;
        case '0':
    xtouch[1]=0;
    
    break;
        case '1':
    xtouch[1]=1;
    break;
        case '2':
    xtouch[1]=2;
    break;
        case '3':
    xtouch[1]=3;
    break;
        case '4':
    xtouch[1]=4;
    break;
        case '5':
    xtouch[1]=5;
    break;
        case '6':
    xtouch[1]=6;
    break;
        case '7':
    xtouch[1]=7;
    break;
        case '8':
    xtouch[1]=8;
    break;
        case '9':
    xtouch[1]=9;
    break;
    default:
    xtouch[1]=0;break;}
    i++;
    
switch(view[i]){
        case',':
        goto ygettouch;
        case '0':
    xtouch[2]=0;
    i++;
    break;
        case '1':
    xtouch[2]=1;
    i++;
    break;
        case '2':
    xtouch[2]=2;
    i++;
    break;
        case '3':
    xtouch[2]=3;
    i++;
    break;
        case '4':
    xtouch[2]=4;
    i++;
    break;
        case '5':
    xtouch[2]=5;
    i++;
    break;
        case '6':
    xtouch[2]=6;
    i++;
    break;
        case '7':
    xtouch[2]=7;
    i++;
    break;
        case '8':
    xtouch[2]=8;
    i++;
    break;
        case '9':
    xtouch[2]=9;
    i++;
    break;
    default:
    xtouch[2]=0;break;}
ygettouch:
    if(i==1){xtouc=xtouch[0];j=i;}
    if(i==2){xtouc=(xtouch[0]*10)+xtouch[1];j=i;}
    if(i==3){xtouc=(xtouch[0]*100)+(xtouch[1]*10)+(xtouch[2]);j=i;}
    i++;
  switch(view[i]){
        case '0':
    ytouch[0]=0;break;
        case '1':
    ytouch[0]=1;break;
        case '2':
    ytouch[0]=2;break;
        case '3':
    ytouch[0]=3;break;
        case '4':
    ytouch[0]=4;break;
        case '5':
    ytouch[0]=5;break;
        case '6':
    ytouch[0]=6;break;
        case '7':
    ytouch[0]=7;break;
        case '8':
    ytouch[0]=8;break;
        case '9':
    ytouch[0]=9;break;
    default:
    ytouch[0]=0;break;}
    i++;
      switch(view[i]){
        case']':
        goto endofgettouch;
        case '0':
    ytouch[1]=0;break;
        case '1':
    ytouch[1]=1;break;
        case '2':
    ytouch[1]=2;break;
        case '3':
    ytouch[1]=3;break;
        case '4':
    ytouch[1]=4;break;
        case '5':
    ytouch[1]=5;break;
        case '6':
    ytouch[1]=6;break;
        case '7':
    ytouch[1]=7;break;
        case '8':
    ytouch[1]=8;break;
        case '9':
    ytouch[1]=9;break;
    default:
    ytouch[1]=0;break;}
     i++;
      switch(view[i]){
        case']':
        goto endofgettouch;break;
        case '0':
    ytouch[2]=0;break;
        case '1':
    ytouch[2]=1;break;
        case '2':
    ytouch[2]=2;break;
        case '3':
    ytouch[2]=3;break;
        case '4':
    ytouch[2]=4;break;
        case '5':
    ytouch[2]=5;break;
        case '6':
    ytouch[2]=6;break;
        case '7':
    ytouch[2]=7;break;
        case '8':
    ytouch[2]=8;break;
        case '9':
    ytouch[2]=9;break;
    default:
    ytouch[2]=0;break;}
    i++;
    endofgettouch:
    if((i-j)==2){ytouc=ytouch[0];}
    if((i-j)==3){ytouc=(ytouch[0]*10)+ytouch[1];}
    if((i-j)==4){ytouc=(ytouch[0]*100)+(ytouch[1]*10)+ytouch[2];}
  
}

it works right but not well because the values are correct always but it takes a long time to read the position of touch point about 800ms!!

would you plz help me to find a better solution?
thanks a lot.

2

....and that's why we ask you to use CODE TAGS

3

AWOL:
....and that's why we ask you to use CODE TAGS

sorry I'm beginner here.

4

Given that there's a sticky thread at the top of this section of the forum that explains how to use the forum, that's a pretty weak excuse.

Now, please edit your original post to add code tags, so that we can read it as you intended.

5

AWOL:
Given that there's a sticky thread at the top of this section of the forum that explains how to use the forum, that's a pretty weak excuse.

Now, please edit your original post to add code tags, so that we can read it as you intended.

thank you for noticing.
if you can help me to find a workable solution I'll be so thankful.

6
  1. why do you post code in italics; see AWOL's reply
  2. get rid of goto's
  3. big part of the switch statements like this can be rewritten to cater for all values between '0' and '9'
case '0':
    ytouch[2]=0;break;
case '1':
    ytouch[2]=1;break;
...
...

Rewrite as

ytouch[2] = view[I] - '0';

That will make your code a lot easier to read.

7

but it takes a long time to read the position of touch point about 800ms!!

I don't use readString, but how long is its timeout?

8

Have a look at the examples in Serial Input Basics - simple reliable ways to receive data. There is also a parse example to illustrate how to extract numbers from the received text.

...R