how to add the calculation of temperature in my source code

[skimask]

i using the 16F877A PIC, and the temperature sensor i using LM35DZ and i only want clesius and count form 0-100oC because i want to measuring the boiler and i using the cable around 4meter only and using power supply +5V so all thing i let u all knw very clearly ad and i knw my english no good no lought ppl....and that is my assignment...i know u all no help ppl to do assignment so i jst want to ask how to adding the math formula in my program and where can get it the formula becasue i no stronge in math so want to ask u all to help me....!!!

How many times do you have to be reminded that there is a SEARCH function here (not to mention GOOGLE returns a couple dozen decent hits...).
The SEARCH here, gives me 19 hits (including one practically pre-made example, linked on a different site, but nonetheless, practically complete), and of those 19 hits, 12 of them have working code in them.

[Luciano]

Hi,

Try that on your breadboard.

(Click to enlarge the picture)

The original tutorial + code can be found here:
http://www.rentron.com/PicBasic/LM34.htm

LM35 datasheet:
http://www.national.com/ds/LM/LM35.pdf

The code below will work with the above connections.
Note that you will have to add the DEFINE + code for the LCD.

Best regards,

Luciano

DEFINE osc 4            ' We're using a 4 MHz oscillator
DEFINE ADC_BITS 8       ' Set A/D for 8-bit operation
DEFINE ADC_CLOCK 1      ' Set A/D clock Fosc/8
DEFINE ADC_SAMPLEUS 50  ' Set A/D sampling time @ 50 uS
' Add the LCD DEFINEs here <<<<<<<<<<<<<<<<<<<<<<<<<
samples VAR WORD        ' Multiple A/D sample accumulator
sample  VAR BYTE        ' Holds number of samples to take
temp    VAR BYTE        ' Temperature storage
samples = 0             ' Clear samples accumulator on power-up

    TRISA = %11111111   ' Set PORTA to all input
    ADCON1 = %00000011  ' Set PORTA.0,1,2,5 = A/D, PortA.3 = +Vref
    PAUSE 500           ' Wait .5 second

loop:

    FOR sample = 1 TO 20    ' Take 20 samples
        ADCIN 0, temp       ' Read channel 0 into temp variable
        samples = samples + temp ' Accumulate 20 samples
        PAUSE 250           ' Wait approximately 1/4 seconds per loop
    NEXT sample

    temp = samples/20
    
    LCDOUT $FE, 1 ' Clear LCD
    LCDOUT "Temp: ",DEC temp,"'C" 

    samples = 0             ' Clear old sample accumulator
    GOTO loop               ' Do it forever

    END

[slimpeng]

hello....Luciano....the potentiometer how many resister....10K,100k or 5k.....i want to comfont i scare will burn off my pic....and i want say thanks u so much here....and helpping me..thanks man...!!!!

[Luciano]

Hi,

The value of the potentiometer is 10k.
(The value is visible on the picture of my previous post, click on the picture to enlarge).

Note that you can also use a 5k potentiometer. There is no danger for
the microcontroller.

Set the potentiometer in its middle point. Connect the red lead of your
multimeter (voltmeter) to the pin 5 of the PIC and connect the black lead
of your multimeter to ground (GND). Adjust the potentiometer so that on the
multimeter you see 2.55V. If you don't have a multimeter, just set the
potentiometer in its middle point.

Best regards,

Luciano


(Click to enlarge the picture)

[slimpeng]

hi.....Luciano.........i get the result ad.....very thankful ....u helping me....thanks u so much...thank.....and also wish u all the best....!!!!

[Archangel]

Hi Luciano,
How do you make those great pictures?
JS

[Luciano]

Hi Joe,

Microsoft Paint.

The 16F877A was taken from the datasheet, the multimeter and potentiometer from the WEB.
(Google search images, 100% copyright violation, sorry about that).

Best regards,

Luciano