; ; keypad tone generator with wakeup on keypress ; DEVICE PIC16C56,HS_OSC,PROTECT_OFF,WDT_OFF TONE_DURATION equ 30000 audioport equ RA ROWMASK equ 00000001b COLMASK equ 00000010b keyport equ RB KEYMASK equ 00001111b col0 equ RB.4 col1 equ RB.5 col2 equ RB.6 temp equ 09h colcount equ 0ah ccount equ 0bh rowcount equ 0ch rcount equ 0dh tonetimehi equ 0eh tonetimelo equ 0fh row0 equ 10h ; current state of key row 0 row1 equ 11h ; current state of key row 1 row2 equ 12h ; current state of key row 2 keycode equ 13h RESET Start zzzzz clrb col0 clrb col1 clrb col2 sleep ; KeyMap -- map key ID to DTMF tone code KeyMap jmp PC+W ; straightforward matrix ; retw 0000b,0001b,0010b ; retw 0100b,0101b,0110b ; retw 1000b,1001b,1010b ; retw 1100b,1101b,1110b ; PacTec brain damaged membrane keyboard retw 1000b,0000b,1100b retw 0100b,1001b,0001b retw 1101b,0101b,1010b retw 0010b,1110b,0110b ;697 Hz 90 123A row ;770 Hz 81 456B row ;852 Hz 73 789C row ;941 Hz 66 *0#D row ;1209 Hz 52 147* col ;1336 Hz 47 2580 col ;1477 Hz 42 369# col ;1633 Hz 38 ABCD col RowTab jmp PC+W retw 90,81,73,66 ColTab jmp PC+W retw 52,47,42,38 ; ; DTMF_send -- send a DTMF tone pair as encoded in W on entry. ; encoding is xxxxRRCC where x = dont care, RR = row#, CC = col# ; DTMF_send ; get row and col encoding into rowcount,colcount mov colcount,W mov rowcount,W and colcount,#00000011b rr rowcount rr rowcount and rowcount,#00000011b ; replace with actual counts from lookup tables mov W,colcount call ColTab mov colcount,W mov W,rowcount call RowTab mov rowcount,W ; preload counters && timers mov rcount,rowcount mov ccount,colcount mov tonetimehi,#TONE_DURATION< mov tonetimelo,#TONE_DURATION> :dtmf_loop ; time to stop? dec tonetimelo jnz :keepon dec tonetimehi snz ret ; done! get out. :keepon ; wait for clock tick mov temp,RTCC :tickwait mov W,RTCC xor W,temp jz :tickwait ; decrement counters djnz rcount,:checkcol ; row count reached zero -- toggle audio and reset counter mov W,audioport xor W,#ROWMASK mov audioport,W mov rcount,rowcount :checkcol djnz ccount,:dtmf_loop ; col count reached zero -- toggle audio and reset counter mov W,audioport xor W,#COLMASK mov audioport,W mov ccount,colcount jmp :dtmf_loop Scan clrb col0 mov row0,keyport setb col0 xor row0,#KEYMASK and row0,#KEYMASK clrb col1 mov row1,keyport setb col1 xor row1,#KEYMASK and row1,#KEYMASK clrb col2 mov row2,keyport setb col2 xor row2,#KEYMASK and row2,#KEYMASK ret Decode clr keycode test row0 jz :tryrow1 ; definitely a bit on in row0 mov keycode,#1 :loop0 snb row0.0 ret rr row0 inc keycode jmp :loop0 :tryrow1 test row1 jz :tryrow2 ; definitely a bit on in row1 mov keycode,#5 :loop1 snb row1.0 ret rr row1 inc keycode jmp :loop1 :tryrow2 test row2 snz ret ; definitely a bit on in row2 mov keycode,#9 :loop2 snb row2.0 ret rr row2 inc keycode jmp :loop2 Start mov OPTION,#00000100b ; RTCC @ 125 KHz mov !RB,#00001111b mov !RA,#0000b ; all outputs setb col0 setb col1 setb col2 Wakeup call Scan ; read keyboard call Decode ; decode bit pattern to key ID test keycode jz :release ; if no key, don't send dec keycode mov W,keycode ; get key ID call KeyMap ; map key ID to DTMF code call DTMF_send ; send DTMF tone ; now wait for key to be released and sleep :release call Scan call Decode test keycode jnz :release jmp zzzzz
file: /Techref/microchip/dtmf-en-dt.htm, 3KB, , updated: 2009/2/13 15:23, local time: 2024/8/14 23:17,
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