Joachim Andersen / keypad

11

Dependents:   Program_R11

keypad.cpp@11:a45e64141ce6, 2012-11-03 (annotated)

Committer:
gj_schoneveld
Date:
Sat Nov 03 23:33:52 2012 +0000
Revision:
11:a45e64141ce6
Parent:
10:9a9ec143840b
Child:
12:e6623f165199
Added support for polling.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
yoonghm 0:2df66331c109 1 #include "keypad.h"
yoonghm 0:2df66331c109 2
yoonghm 0:2df66331c109 3 Keypad::Keypad(PinName row3, PinName row2, PinName row1, PinName row0,
yoonghm 0:2df66331c109 4 PinName col3, PinName col2, PinName col1, PinName col0,
yoonghm 0:2df66331c109 5 int debounce_ms):
gj_schoneveld 10:9a9ec143840b 6 _row0(row0), _row1(row1), _row2(row2), _row3(row3),
gj_schoneveld 10:9a9ec143840b 7 _cols(col0, col1, col2, col3)
gj_schoneveld 10:9a9ec143840b 8 {
gj_schoneveld 11:a45e64141ce6 9 _rows[0] = &_row0;
gj_schoneveld 11:a45e64141ce6 10 _rows[1] = &_row1;
gj_schoneveld 11:a45e64141ce6 11 _rows[2] = &_row2;
gj_schoneveld 11:a45e64141ce6 12 _rows[3] = &_row3;
yoonghm 0:2df66331c109 13 _debounce = debounce_ms;
gj_schoneveld 10:9a9ec143840b 14 _row0.mode(PullUp);
gj_schoneveld 10:9a9ec143840b 15 _row1.mode(PullUp);
gj_schoneveld 10:9a9ec143840b 16 _row2.mode(PullUp);
gj_schoneveld 10:9a9ec143840b 17 _row3.mode(PullUp);
gj_schoneveld 10:9a9ec143840b 18 _cols.mode(OpenDrain);
gj_schoneveld 10:9a9ec143840b 19 _cols.output();
gj_schoneveld 11:a45e64141ce6 20 }
gj_schoneveld 11:a45e64141ce6 21
gj_schoneveld 11:a45e64141ce6 22 void Keypad::_setupFallTrigger(void)
gj_schoneveld 11:a45e64141ce6 23 {
gj_schoneveld 11:a45e64141ce6 24 _row0.fall(this, &Keypad::_callback);
gj_schoneveld 11:a45e64141ce6 25 _row1.fall(this, &Keypad::_callback);
gj_schoneveld 11:a45e64141ce6 26 _row2.fall(this, &Keypad::_callback);
gj_schoneveld 11:a45e64141ce6 27 _row3.fall(this, &Keypad::_callback);
yoonghm 0:2df66331c109 28 }
yoonghm 0:2df66331c109 29
gj_schoneveld 10:9a9ec143840b 30 void Keypad::Start(void)
gj_schoneveld 10:9a9ec143840b 31 {
gj_schoneveld 11:a45e64141ce6 32 /* make the columns zero so they can pull rows down */
yoonghm 0:2df66331c109 33 _cols = 0x00;
yoonghm 0:2df66331c109 34 }
yoonghm 0:2df66331c109 35
gj_schoneveld 10:9a9ec143840b 36 void Keypad::Stop(void)
gj_schoneveld 10:9a9ec143840b 37 {
gj_schoneveld 11:a45e64141ce6 38 /* make the columns one so they cannot pull any rows down anymore */
gj_schoneveld 11:a45e64141ce6 39 _cols = ~0x00;
gj_schoneveld 10:9a9ec143840b 40 }
gj_schoneveld 10:9a9ec143840b 41
gj_schoneveld 10:9a9ec143840b 42 void Keypad::CallAfterInput(uint32_t (*fptr)(uint32_t index))
gj_schoneveld 10:9a9ec143840b 43 {
yoonghm 0:2df66331c109 44 _input.attach(fptr);
gj_schoneveld 11:a45e64141ce6 45 _setupFallTrigger();
gj_schoneveld 11:a45e64141ce6 46 }
gj_schoneveld 11:a45e64141ce6 47
gj_schoneveld 11:a45e64141ce6 48 int Keypad::DebouncedScan()
gj_schoneveld 11:a45e64141ce6 49 {
gj_schoneveld 11:a45e64141ce6 50 int key1 = Scan();
gj_schoneveld 11:a45e64141ce6 51
gj_schoneveld 11:a45e64141ce6 52 /* debounce */
gj_schoneveld 11:a45e64141ce6 53 wait_ms(_debounce);
gj_schoneveld 11:a45e64141ce6 54
gj_schoneveld 11:a45e64141ce6 55 int key2 = Scan();
gj_schoneveld 11:a45e64141ce6 56
gj_schoneveld 11:a45e64141ce6 57 if (key1 != key2)
gj_schoneveld 11:a45e64141ce6 58 return -1;
gj_schoneveld 11:a45e64141ce6 59 else
gj_schoneveld 11:a45e64141ce6 60 return key1;
yoonghm 0:2df66331c109 61 }
yoonghm 0:2df66331c109 62
gj_schoneveld 11:a45e64141ce6 63 int Keypad::Scan()
gj_schoneveld 10:9a9ec143840b 64 {
gj_schoneveld 11:a45e64141ce6 65 /* lookup row */
gj_schoneveld 11:a45e64141ce6 66 int r = -1;
gj_schoneveld 11:a45e64141ce6 67 for (r = 0; r < row_count; r++) {
gj_schoneveld 11:a45e64141ce6 68 if (*_rows[r] == 0)
gj_schoneveld 11:a45e64141ce6 69 break;
gj_schoneveld 11:a45e64141ce6 70 }
yoonghm 0:2df66331c109 71
gj_schoneveld 11:a45e64141ce6 72 /* if we didn't find a valid row, return */
gj_schoneveld 11:a45e64141ce6 73 if (!(0 <= r && r < row_count))
gj_schoneveld 11:a45e64141ce6 74 return -1;
gj_schoneveld 11:a45e64141ce6 75
gj_schoneveld 11:a45e64141ce6 76 /* scan columns to find out which one pulls down the row */
yoonghm 0:2df66331c109 77 int c = -1;
gj_schoneveld 11:a45e64141ce6 78 for (c = 0; c < col_count; c++) {
gj_schoneveld 11:a45e64141ce6 79 _cols = ~(1 << c);
gj_schoneveld 11:a45e64141ce6 80 if (*_rows[r] == 0)
gj_schoneveld 11:a45e64141ce6 81 break;
yoonghm 0:2df66331c109 82 }
gj_schoneveld 11:a45e64141ce6 83
gj_schoneveld 11:a45e64141ce6 84 /* re-energize all columns */
gj_schoneveld 11:a45e64141ce6 85 Start();
gj_schoneveld 11:a45e64141ce6 86
gj_schoneveld 11:a45e64141ce6 87 /* if we didn't find a valid column, return */
gj_schoneveld 11:a45e64141ce6 88 if (!(0 <= c && c < col_count))
gj_schoneveld 11:a45e64141ce6 89 return -1;
gj_schoneveld 11:a45e64141ce6 90
gj_schoneveld 11:a45e64141ce6 91 return r * col_count + c;
yoonghm 0:2df66331c109 92 }
yoonghm 0:2df66331c109 93
gj_schoneveld 11:a45e64141ce6 94 void Keypad::_callback()
gj_schoneveld 10:9a9ec143840b 95 {
gj_schoneveld 11:a45e64141ce6 96 /* lookup */
gj_schoneveld 11:a45e64141ce6 97 int position = DebouncedScan();
gj_schoneveld 11:a45e64141ce6 98
gj_schoneveld 11:a45e64141ce6 99 /* call back a valid position */
gj_schoneveld 11:a45e64141ce6 100 if (position >= 0)
gj_schoneveld 11:a45e64141ce6 101 _input.call(position);
yoonghm 0:2df66331c109 102 }
yoonghm 0:2df66331c109 103