6172 CAN Micro Controller Module AN010

This application example is not yet completely tested

4 x 4 keyboard matrix

This application example enables the user to input 16 keys (switches) in a 4 x 4 matrix.

This example can be combined with AN009 to create a keyboard + LCD display module for CANopen.

        header  "4 x 4 keyboard matrix AN010"
 
keybrd: equ     0               ;keyboard matrix memory location (2 bytes)
 
row1:   equ     0               ;row 1 select bit (OUT9)
row2:   equ     1               ;row 2 select bit (OUT10)
row3:   equ     2               ;row 3 select bit (OUT11)
row4:   equ     3               ;row 4 select bit (OUT12)
 
 
temp:   equ     63              ;scratchpad memory
 
 
;initialization sequence 
 
        sequence seq_0 
 
        ldwc    0               ;clear all 4 row outputs
        stwm    PORTB
 
        srdy                    ;READY output active 
        enasq   0               ;enable sequences
        endsq
 
;read all 4 keyboard rows to memory    
 
        sequence seq_3,5        ;execute this sequence every 50 mS
 
        maskc   %00001111       ;read only lower 4 bits of port C
        
        setb    row1            ;activate keyboard row 1
        delay   5               ;some delay before reading it...
        inpc    temp            ;read keyboard row 1 to temp
        resb    row1
        setb    row2            ;now activate keyboard row 2
        delay   5               ;some delay before reading it...
        ldwm    PORTC           ;read keyboard row 2 in W
        resb    row2
        setb    row3            ;now activate keyboard row 3
        shlc    4               ;row 2 into upper 4 bits
        orwm    temp            ;add row 1
        stwm    keybrd          ;result to memory
        inpc    temp            ;read keyboard row 3 to temp
        resb    row3
        setb    row4            ;now activate keyboard row 4
        delay   5               ;some delay before reading it...
        ldwm    PORTC           ;read keyboard row 4
        resb    row4
        shlc    4               ;row 4 into upper 4 bits
        orwm    temp            ;add row 3
        stwm    keybrd+1        ;result to memory
        endsq
 
;this sequence executes in about 230 µS
        
        end

Assuming that all 6172 objects are in their default state, the following objects need to be adjusted (if a PDO is used):

 

1	Subindex	Value	Description
PDO mapping of transmit PDO 1
1A00h	0	2	2 objects in transmit PDO 1
1A00h	1	60000108h	memory location 0
1A00	2	60000208h	memory location 2
Enable PDO transmission on any change of memory location 0-1
6006	1	255	memory location 0
6006	2	255	memory location 1

The keyboard now can be read by:

• automaticaly after a state change of any switch (transmit PDO1 is sent by 6172, minimal interval time set by sequence 1 interval time (50 mS))
  (60 bits message)
• a PDO request of transmit PDO1
  (one 44 and one 60 bits message)
• reading object 6120, subindex 1, using one SDO read.
  (2 x 108 bits message)
• reading object 6000h, subindex 1 and 2, using two SDO reads
  (4 x 108 bits messages)

Copy and Paste this part direct after the declarations in the canappl.bas program
this program can be found on the 6197 designers kit diskette or
ordered separately as service part together with one of our CAN products.  

APPLICATION:
 
'This simple program is made for one 6172 and a 6390 as CAN bus interface
'the following assumptions are done:
'- 6390 is connected to COM2
'- 6172 ID = 1, CANbus speed = 50 kBAUD
'- assembled sequence file is "AN010.seq"
 
'The keyboard is read using the PDO, if the PDO isn't received
'within 5 seconds, it is requested.
'The results are displayed as one line with a 16 bit binary string
'this continues until the user presses enter
 
CLS
PRINT "CD Systems 6172 AN010 DEMO program"
PRINT
 
Activate6390 2, 19200                          '6390 works at COM2, 19200 BAUD
SetCANBUSSpeed 50                                         'CAN BUS at 50 kBAUD
 
C% = CheckSequence%(1, "AN005.seq")     'download sequence if not already done
 
C% = PutU8%  (1, &h1A00, 0, 2)          '2 objects in transmit PDO1
C% = PutU32% (1, &h1A00, 1, &h60000108) 'transmit PDO1 from memory 0
C% = PutU32% (1, &h1A00, 2, &h60000208) 'transmit PDO1 from memory 1
 
C% = PutU8% (1, &h6006, 1, 255)         'enable transmit PDO on any change
C% = PutU8% (1, &h6006, 2, 255)
 
SendNMTCommand (1, 1)                   'node in operational state
 
BT = TIMER - 6                          'force immediate request
 
PDOCOB% = (1 + 384) * 32                'tx PDO1 COB ID shifted left 5 bits
 
DO
' send a transmit PDO1 remote request if nothing received after 5 seconds 
  IF (BT + 5) < TIMER THEN
     SendToCAN (CANIDS$ (PDOCOB% + &h10))
     BT = TIMER
  END IF
 
' check if the transmit PDO is received
  R$ = ReceiveFromCAN$
  IF LEN (R$) > 1 THEN                            'anything received?
     IF (CANIDR% (R$) AND &hFFE0) = PDOCOB% THEN  'PDO1 tx received?
 
       LOCATE 10,1
       FOR I% = 3 TO 4: M% = 1                    '2 bytes in PDO
        FOR B% = 1 TO 8                           '8 keys in a byte
 
         IF (ASC(MID$(R$,I%)) AND M%) THEN PRINT "1"; ELSE PRINT "0";
         M% = M% * 2
        NEXT B%
       NEXT I%
 
       BT = TIMER
     END IF
  END IF
LOOP UNTIL INKEY$ = CHR$(13)
 
SendNMTCommand (1, 2)                             'stop node
 
DO                                'clear & ignore any received message
  R$ = ReceiveFromCAN$
LOOP UNTIL R$ = ""
 
 
END