Who can help me checking my Programming

[slimpeng]

yup i know 4-20mA.....so wat should i do it now.....need to change the sensor or jst adding the resistor.......wat valuse of the resistor i need to change it....

[skimask]

yup i know 4-20mA.....so wat should i do it now.....need to change the sensor or jst adding the resistor.......wat valuse of the resistor i need to change it....

You send me the board your prototype is sitting on, and I'll GIVE you the resistor you need.
Ever heard of a DS1820 or it's derivatives?

[slimpeng]

now i using the voltage divider rule and the resister i will 18ohm and the test cricuit i will post at below and i got hear that D1820 that is digital temperature sensor...but i duno how to use it...i no use that before....and now how to make the sensor become stable.......

on the pict the blue colour is my temperature sensor....
and the resistor value is 18ohm
and the red colour wire i connet to ADC on port A.0
and the whole the circuit i also post at here ad...i hope u can help me....

if really want to change the sensor D1820 the circuit how it look like and where can get it and the programe need to write again or not need...!

[Archangel]

Hi slimpeng,
Here! Already written, and links to where to get it. You will be here 2 years from now trying to accomplish your goal with that thermistor. Oh, and please do try to use Google, it really does work to bring you good things, like data sheets, vendors, etc. . .

http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2815/t/al

@MyConfig = _HS_OSC & _WDT_ON & _PWRTE_ON & _LVP_OFF 
@MyConfig = MyConfig & _BODEN_OFF 
@ __config  MyConfig
' One-wire temperature for LAB-X1 and DS1820
Define PIC16F877A
@ errorlevel -230
temperature  Var	Word			' Temperature storage
count_remain Var    Byte	 	    ' Count remaining
count_per_c  Var	Byte			' Count per degree C

DQ	Var	PORTC.0			' One-wire data pin
define OSC 20
TrisA = %00000000
TrisB = %11111111

' Define LCD registers and bits
DEFINE LCD_DREG PORTA
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTA
DEFINE LCD_RSBIT 5
DEFINE LCD_EREG PORTA
DEFINE LCD_EBIT 4
DEFINE LCD_BITS 4
DEFINE LCD_LINES 4
DEFINE LCD_COMMANDUS 2000	 'Define delay time between sending LCD commands
DEFINE LCD_DATAUS 50	     'Define delay time between data sent.

  CMCON  = 7
	ADCON1 = 7			' Set PORTA and PORTE to digital
	Low PORTE.2			' LCD R/W line low (W)
pause 500
LCDOUT 254,1,"initializing"
mainloop: OWOut DQ, 1, [$CC, $44]       ' Start temperature conversion

waitloop: OWIn DQ, 4, [count_remain]	' Check for still busy converting
	If count_remain = 0 Then waitloop

	OWOut DQ, 1, [$CC, $BE]		' Read the temperature
        OWIn DQ, 0, [temperature.LOWBYTE, temperature.HIGHBYTE, Skip 4, count_remain, count_per_c]

	' Calculate temperature in degrees C to 2 decimal places (not valid for negative temperature)
	temperature = (((temperature >> 1) * 100) - 25) + (((count_per_c - count_remain) * 100) / count_per_c)
	Lcdout $fe, 1, DEC (temperature / 100), ".", DEC2 temperature, " C"

	' Calculate temperature in degrees F to 2 decimal places (not valid for negative temperature)
	temperature = (temperature */ 461) + 3200
	Lcdout $fe, $c0, DEC (temperature / 100), ".", DEC2 temperature, " F"

        Pause 1000                      ' Display about once a second

	Goto mainloop			' Do it forever

[skimask]

i will post at below and i got hear that D1820 that is digital temperature sensor...but i duno how to use it...i no use that before....and now how to make the sensor become stable.......

if really want to change the sensor D1820 the circuit how it look like and where can get it and the programe need to write again or not need...!

Datasheets?
Google?
Search the forum?

I'm done and out...Too much time used up already...not enough legwork at the other end.
The items referred to in Post #6 have run out.

[slimpeng]

last question....why the temperature going to high....oC and my LCD cant display any oC when going to low oC the LCD can display bck the value....why...! is my progrme problme...or what happen who can let me knw below is my new programe....!!!!

help to check it


'************************************************* ***************
'* Name : UNTITLED.BAS *
'* Author : [select VIEW...EDITOR OPTIONS] *
'* Notice : Copyright (c) 2008 [select VIEW...EDITOR OPTIONS] *
'* : All Rights Reserved *
'* Date : 1/23/2008 *
'* Version : 1.0 *
'* Notes : *
'* : *
'************************************************* ***************
Define LCD_DREG PORTB
Define LCD_DBIT 4
Define LCD_RSREG PORTB
Define LCD_RSBIT 0
Define LCD_EREG PORTB
Define LCD_EBIT 1

' Define ADCIN parameters '

Define ADC_BITS 8 ' Set number of bits in result
Define ADC_CLOCK 3 ' Set clock source (3=rc)
Define ADC_SAMPLEUS 50 ' Set sampling time in uS
include"modedefs.bas"

TRISB=%11111111

pause 2
LCDOUT 254,1,2,2,2,"WELCOME MY"
LCDOUT 254,192,2,"MONITOR SYSTEM"

pause 3
LCDOUT 254,1,"MY STARTING"
LCDOUT 254,192,2,2,2,2,2,"TEMPERATURE"

B0 var byte ' Create TEMPERATURE to store result

TRISC.6=0
TRISA = %11111111 ' Set PORTA to all input
ADCON1 =%00001010 ' Set PORTA analog
Low PORTB.2 ' LCD R/W line low (W)

Pause 1000

loop:

ADCIN 0,B0 ' Read channel 0 to adval
Lcdout $fe, 1 ' Clear LCD
Lcdout "Value: ",DEC B0,"'C" ' Display the decimal value
serout portc.6,n2400,[#b0]
Pause 5000 ' Wait .5 second

Goto loop ' Do it forever
End