PIC18f ASCII

Thread Starter

Dritech

Joined Sep 21, 2011
869
Hi all,

I am using an ADC to display temperature on an LCD.(using assembly).

Can someone help me in separating a two character number and convert each character to ASCII ??

For example if the temperature is 25°C, separate 2 from 5 and convert them to ASCII (i.e. 00110010, 00110101)

Thanks.
 

t06afre

Joined May 11, 2009
5,934
What is your data material before conversion. Is it just a raw number from the ADC? That first need to be scaled and then converted to ASCII
 

Thread Starter

Dritech

Joined Sep 21, 2011
869
Hi.
Thanks for the replies.

What is your data material before conversion. Is it just a raw number from the ADC? That first need to be scaled and then converted to ASCII
The input of the ADC will be from a PT1000 which is connected to an OP-AMP. The ADC is set to increment 1 bit for every degree (i.e. 1 degree = 00000001... 2 degree= 00000010 etc). Now i need to convert the mentioned output binary to ASCII. From 1 to 9 degree its no problem since all i have to do is add 48 to it, but when the value is with two digits (ex. 25degree) i have to separate 2 and add 48 to it and the same with 5.

I will read the tutorials which Markd77 gave and see if i manage to make it work.

Thanks.
 

Thread Starter

Dritech

Joined Sep 21, 2011
869
Hi, thanks again Markd77. I managed to make it work with the help from the link you gave me.

The only problem is that i cannot understand how the binary is being converted to ASCII. Can someone explain the conversion routine (coding below) with comments please? I would appreciate it a lot.

Thanks in advance.

Rich (BB code):
BIN2BCD

;---------------------


;in: BIN
;out huns. tens, ones

;uses ADD-3 algoerthm

movlw 8
movwf count
clrf huns
clrf tens
clrf ones

BCDADD3

movlw 5
subwf huns, 0
btfsc STATUS, C
CALL ADD3HUNS

movlw 5
subwf tens, 0
btfsc STATUS, C
CALL ADD3TENS

movlw 5
subwf ones, 0
btfsc STATUS, C
CALL ADD3ONES

decf count, 1
bcf STATUS, C
rlf BIN, 1
rlf ones, 1
btfsc ones,4 ; 
CALL CARRYONES
rlf tens, 1

btfsc tens,4 ; 
CALL CARRYTENS
rlf huns,1
bcf STATUS, C

movf count, 0
btfss STATUS, Z
GOTO BCDADD3


movf huns, 0 ; add ASCII Offset
addlw h'30'
movwf huns

movf tens, 0 ; add ASCII Offset
addlw h'30'
movwf tens

movf ones, 0 ; add ASCII Offset
addlw h'30'
movwf ones

RETURN

ADD3HUNS

movlw 3
addwf huns,1

RETURN

ADD3TENS

movlw 3
addwf tens,1

RETURN

ADD3ONES

movlw 3
addwf ones,1

RETURN

CARRYONES
bcf ones, 4
bsf STATUS, C
RETURN

CARRYTENS
bcf tens, 4
bsf STATUS, C
RETURN
 
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