software filtering

[lanceaustin]

i have made the pulse dialing code to some extend and need advice your all of you...

Objective:-

Detecting Signal Digit Dialing.considering only one telephone.

If digit "2" is pressed disconnect dial tone from the the telephone set otherwise keep connecting the dial tone.

; CHECKING ONE TELEPHONE LINE WITH MT8816 AND AT89C52
; P2.0 FOR DETECTING OFF HOOK (1) AND ON HOOK (0)
; Dial Tone Y0 OF MT8816 and telephone via slic is connected with X2
; ADDRESS LINE + DATA PIN OF MT8816 WITH P1 (date pin p1.7)
; Strobe = p3.7
; crsytal 11.05KOH



ORG 00H
LJMP MAIN


ORG 0030H
MAIN:
MOV P0,#00000000B ;port IS CLEARED
MOV P3,#00000000B ;StROBE IS CLEARED
MOV P2,#00000000B ;RESETING THE PIN
MOV P1,#00000000B ;RESETING THE PIN

OFF:
JNB P2.0,OFF ;WAITING FOR OFF-HOOK

CALL DELAY_10MS ;for debouncing, filtering codition
MOV P1,#10010000B ;x2-y0 DIAL TONE connection

SETB P3.7 ;STROBE IS SET HIGH

ON:
JB P2.0,ON ;waiting for digit dial
MOV R6,#00D ;pulse counting regsiter

J:
CALL DELAY_60MS ; pulse low time
INC R6 ;calculate no. of zeros
CALL DELAY_40MS ;pulse high time
CALL DELAY_10MS ;software filtering
JNB P2.0,J ;checking for more than 1 pulse
JB P2.0,CHECK3 ;check if all pulses came

CHECK3:
CJNE R6,#02D,DO ;dialed digit is 2 then remove dial tone

CLR P1.7
CLR P3.7

DO:
JNB P2.0,MAIN ;waiting on hook
SJMP DO


DELAY_60MS:
MOV R0,#05D
L2: MOV R1,#53D
L1: MOV R2,#250D
DJNZ R2,$
DJNZ R1,L1
DJNZ R0,L2
RET


DELAY_40MS:
MOV R0,#05D
A2: MOV R1,#49D
A1: MOV R2,#180D
DJNZ R2,$
DJNZ R1,A1
DJNZ R0,A2
RET

DELAY_10MS:
MOV R0,#05D
C2: MOV R1,#10D
C1: MOV R2,#200D
DJNZ R2,$
DJNZ R1,C1
DJNZ R0,C2
RET
END

Now i have used the above program firstly to see if low comes one dialing a digit it worked...but when iam using it to count the more than one pulse its not working...please advice some thing about the above.

Also since maximum time for receiving the pulses will 1 second which will be needed when digit "0" is pressed. I have tried to make a counter which multiply 40 milli seconds with 30 = 1200 micro-seconds
which checks after each decrement whether another pulse has arrived or not but it also did not worked...

actually the pulse counting register is counting more than one pulse..

 

[lanceaustin]

Ok People,,
Talking about the same program as i have posted before, but now i have made only one change is that, that is the Make and Break Ratio are same i.e. 40 Milli Seconds..
Now this is also not working in a proper order but it is doing something which is:-

By pressing signal digit i get following result considering the what is in CJNE command:-

1 or 2 if pressed and in CJNE command i R7=1 then it work

3 or 4 if pressed and in CJNE command i have used R7=2 then it work

5 or 6 if pressed and in CJNE command i have used R7=3 then it work

7 or 8 if pressed and in CJNE command i have used R7=4 then it work

9 or 0 if pressed and in CJNE command i have used R7=5 then it work

At preset two digits represent same number of pulses, i think the problem is clear to all of you..now can some one make out a relation out of this
and provide the correct solution , a solution that is valid for any pulse dialing telephone.

Is it possible that if some how the program is made in such a fashion that instead of counting
the pulses it counts how much time it took for number of pulses to arrive and then compare it with time interval already stored in the memory.


like

Digit Time (seconds)
0 1 second for 10 pulse
9 9/10
8 8/10
7 7/10
6 6/10
5 5/10
4 4/10
3 3/10
2 2/10
1 1/10

please suggest a way out..






; CHECKING ONE TELEPHONE LINE WITH MT8816 AND AT89C52
; P2.0 FOR DETECTING OFF HOOK (1) AND ON HOOK (0)
; SLIC TO X2 PIN31 OF MT8816
; ADDRESS LINE + DATA PIN OF MT8816 WITH P1
; DIAL TONE IS ON Y0 PIN 31 OF MT8816



ORG 00H
LJMP MAIN


ORG 0030H
MAIN:
MOV P0,#00000000B ;port IS CLEARED
MOV P3,#00000000B ;STROBE IS CLEARED
MOV P2,#00000000B ;RESETING THE PIN
MOV P1,#00000000B ;RESETING THE PIN
OFF: JNB P2.0,OFF ;WAITING FOR OFF-HOOK
CALL DELAY
MOV P1,#10010000B ;ADDRESS LINE TO CONNECT Y0 WITH X2 FOR DIAL TONE
SETB P3.7 ;STROBE IS SET HIGH
ON: JB P2.0,ON
MOV R7,#00D
J: CALL DELAY_40MS
INC R7
CALL DELAY_40MS
JNB P2.0,J
JB P2.0,CHECK3
CHECK3: CJNE R7,#05D,DO ;this will detect digit 9 and 0
CLR P1.7
CLR P3.7
DO: JNB P2.0,MAIN
SJMP DO


DELAY_60MS:
MOV R0,#05D
L2: MOV R1,#53D
L1: MOV R2,#250D
DJNZ R2,$
DJNZ R1,L1
DJNZ R0,L2
RET


DELAY_40MS:
MOV R0,#05D
A2: MOV R1,#49D
A1: MOV R2,#180D
DJNZ R2,$
DJNZ R1,A1
DJNZ R0,A2
RET

DELAY_800MS:
MOV R0,#80D
U2: MOV R1,#94D
U1: MOV R2,#100D
DJNZ R2,$
DJNZ R1,U1
DJNZ R0,U2
RET


DELAY:
MOV R0,#05D
C2: MOV R1,#10D
C1: MOV R2,#200D
DJNZ R2,$
DJNZ R1,C1
DJNZ R0,C2
RET
END