Temperature Sensor (LM35 + PIC16F877A)

Hi ;
i'm using PIC16F877A with temperature sensor LM35 . I refered to this work
https://forum.allaboutcircuits.com/blog.php?b=513
but i'm not able to unterstand those instructions :
ADRead = (ADC_Get_Sample(0) * 500) >> 10;
vDisp[0] = ADRead / 100;
vDisp[1] = (ADRead / 10) % 10;
vDisp[2] = ADRead % 10;
Display[1] = vDisp[0] + 48;
Display[2] = vDisp[1] + 48;
Display[3] = vDisp[2] + 48;
NEED YOUR HELP.

ADRead = (ADC_Get_Sample(0) * 500) >> 10;

// consider and ADRead value of 123
vDisp[0] = ADRead / 100; // vDisp[0] will become 1. i.e. integer left dividing 123/100 = 1 (most significant digit)

vDisp[1] = (ADRead / 10) % 10; // vDisp[1] will become 7. i.e. 123/10 = 12, and 12 % 10 is the remained times i.e. 2 (middle digit)

vDisp[2] = ADRead % 10; // vDisp[2] will become remainder of 567/10 i.e. 567/10 = 16 and the remainder is 7 (least significant digit)

The following converts the numbers to ASCII for display on a serial terminal etc. So for 123 above
Display[1] = vDisp[0] + 48; // = 49
Display[2] = vDisp[1] + 48; // = 50
Display[3] = vDisp[2] + 48; // = 51

For ASCII look at https://www.asciitable.com/ and you will see decimal 48 displays character '0'

Hope that helps with the understanding of integer division, remainders and ASCII. Nice question.

Max value of adc is 1023 for 5V input. Max o/p of LM35 is 1.5V. So, max adc value will be 306.9

0 to 306.9 is multiplied by 500

eg:

306.9 * 500 = 153450

153450 >> 10 = 149

149 is approx 150 max temperature of LM35.



These are for extracting digits of the number



149/100 = 1 //hundredths digit
149/10 = 14
14%10 = 4 //tens digit
149%10 = 9 //units digit

Converting int value to ascii charcaters by adding 48 or 0x30



1 + 0x30 = 0x31 = '1'
4 + 0x30 = 0x34 = '4'
9 + 0x30 = 0x39 = '9'

Display[] = "149"

You can replace the above with



or

It's work know ... but there is a little prob , after the conversion to string
the LCD shows the digit far of it's place ?

Try WordToStr command instead of IntToStr

This code change integer to string:
- number 0 is referred to character '0' in ASCII table ('0' has index is 48).