keypad.tmb for the IC51
Reads a 4 by 4 matrix keypad
(Industrologic KP16 or equiv.)
connected to the digital I/O
and sends characters out the
serial port. Exits program if
character is received at serial
port (key pressed on PC).
-------------------------------
NEW
1 A=KEY
--- continue if no key pressed
2 IF A=0 5
3 END
--- read keypad subroutine
5 GOSUB 100
--- zero if no key pressed
6 IF A=0 1
--- print ASCII value
7 PRINT (A)
8 DELAY 2
9 GOTO 1
-------------------------------
--- Read 4 by 4 matrix keypad
--- connected to digital I/O,
--- return ASCII character or
--- zero if no key pressed.
--- Keypad to digital I/O:
--- Col 1   DI1    Row 1   DI5
--- Col 2   DI2    Row 2   DI6
--- Col 3   DI3    Row 3   DI7
--- Col 4   DI4    Row 4   DI8
--- (This is the pinout of the
--- Industrologic KP16 keypad)
-------------------------------
100 A=0
--- DI1 low, the rest high
101 DI=254
--- check row 1
102 IF DI5=1 105
103 A="1"
104 RETURN
--- check row 2
105 IF DI6=1 108
106 A="4"
107 RETURN
--- check row 3
108 IF DI7=1 111
109 A="7"
110 RETURN
--- check row 4
111 IF DI8=1 121
112 A="*"
113 RETURN
--- DI2 low, the rest high
121 DI=253
--- check row 1
122 IF DI5=1 125
123 A="2"
124 RETURN
--- check row 2
125 IF DI6=1 128
126 A="5"
127 RETURN
--- check row 3
128 IF DI7=1 131
129 A="8"
130 RETURN
--- check row 4
131 IF DI8=1 141
132 A="0"
133 RETURN
--- DI3 low, the rest high
141 DI=251
--- check row 1
142 IF DI5=1 145
143 A="3"
144 RETURN
--- check row 2
145 IF DI6=1 148
146 A="6"
147 RETURN
--- check row 3
148 IF DI7=1 151
149 A="9"
150 RETURN
--- check row 4
151 IF DI8=1 161
152 A="#"
153 RETURN
--- DI4 low, the rest high
161 DI=247
--- check row 1
162 IF DI5=1 165
163 A="A"
164 RETURN
--- check row 2
165 IF DI6=1 168
166 A="B"
167 RETURN
--- check row 3
168 IF DI7=1 171
169 A="C"
170 RETURN
--- check row 4
171 IF DI8=1 173
172 A="D"
173 RETURN