The famous ( 8051 based temperaure control fan) , help is seriously needed !

Q1/ why r u using the higher nibble and the lower nibble here
(sometime u set the highr nibble as "high" and some times "low" , same thin with the lower nibble) ?

Light

I am not setting them high or low.. i am masking them..
masking means.. clearing the unwanted bits..
like in above example.. anl a,#0FH
this statement will mask the higher nibble, i.e. making upper four bits as 0. because when you are displaying the upper nibble then you need to mask the lower nibble and when displaying lower nibble the upper nibble has to be masked.

Q2/ the decoded table .... is it going to contain the values of all digits that can be displyed on 7-segment , OR the vaues that is going to be representing the temperature only ?

Light

yes it will contain the value that displays digit on 7-segment..

Q2/ the decoded table .... is it going to contain the values of all digits that can be displyed on 7-segment , OR the vaues that is going to be representing the temperature only ?

Light

yes it will contain the value that displays digit on 7-segment..

[/quote1189471324]

woow , that means alooot of values will be decoded , cuz we hav 2 DUAL ! seven-segment
its like from 24.00°C (24.01° , 24.02° , ...) to 100.00°C, that would take 3 or 4 pages :-)

thank u for these answers.

the prevoise program for the 7-segment can be used right ?
if yes lets move to ADC .

No you just need the values from 0 to 9, as you have to display in multiplexed mode.. so first display first digit and then second digit.. so all you need is decoded table from 0 to 9

Ajay , today i tryd the simple program that shows (45) on the 7-segment to test my hardware , but it didnt show 45 !
insted , the fan worked !!!!!!!!!!!!!! <--- dont ask me how
and the four 7-segments show ( 8 8 8 8) , all the LED r on.

this is the code that i installed it :

ORG 0000

MOV A,P0
MOV A,66H
SETB P1.0
CLR P1.1
MOV A,P0
MOV A,6DH
SETB P1.1
CLR P1.0

RET

DELAY:
MOV R5,#50H
BACK:
MOV R4,#0FFH
DJNZ R4,$
DJNZ R5,BACK



END
--------------------------------------------------

so where is the mistake ?

ORG 0000
CLR P0
start:
MOV A,66H
mov P0,a
SETB P1.0
acall DELAY
CLR P1.0

MOV A,6DH
mov P0,a
SETB P1.1
acall DELAY
CLR P1.1
SJMP start

DELAY:
MOV R5,#20H
BACK:
MOV R4,#0FFH
DJNZ R4,$
DJNZ R5,BACK

END

-------
TRY AGAIN!!

there is 1 error on the 2nd line (CLR P0)
it says : ( segment type mismatch )

??

oops my mistake..
replace clr P0 with mov P0,#00H

you mean replace CLR P0 with MOV P0,#00H

??

oh ok ok , i didnt c the ( mov ) that u wrote

thanks alooot