Rene Greiner
first version of a keypad (4x3) implementation working with interrupts instead of polling.
main.cpp@0:510bbea7c78e, 2011-12-11 (annotated)
- Committer:
- Renegr
- Date:
- Sun Dec 11 08:50:58 2011 +0000
- Revision:
- 0:510bbea7c78e
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| Renegr | 0:510bbea7c78e | 1 | #include "mbed.h" |
| Renegr | 0:510bbea7c78e | 2 | |
| Renegr | 0:510bbea7c78e | 3 | BusInOut colBus( p26, p25, p24); |
| Renegr | 0:510bbea7c78e | 4 | const PinName rowPins[] = { p30, p29, p28, p27 }; |
| Renegr | 0:510bbea7c78e | 5 | |
| Renegr | 0:510bbea7c78e | 6 | volatile bool irqFinished = false; |
| Renegr | 0:510bbea7c78e | 7 | |
| Renegr | 0:510bbea7c78e | 8 | inline char toChar( unsigned char r, unsigned char c) { |
| Renegr | 0:510bbea7c78e | 9 | static const char keytable[] = { '1', '2', '3', 'A', |
| Renegr | 0:510bbea7c78e | 10 | '4', '5', '6', 'B', |
| Renegr | 0:510bbea7c78e | 11 | '7', '8', '9', 'C', |
| Renegr | 0:510bbea7c78e | 12 | '*', '0', '#', 'D' |
| Renegr | 0:510bbea7c78e | 13 | }; |
| Renegr | 0:510bbea7c78e | 14 | return keytable[r*4+c]; |
| Renegr | 0:510bbea7c78e | 15 | } |
| Renegr | 0:510bbea7c78e | 16 | |
| Renegr | 0:510bbea7c78e | 17 | inline char toBinary( unsigned char r, unsigned char c) { |
| Renegr | 0:510bbea7c78e | 18 | static const char keytable[] = { 0x1, 0x2, 0x3, 0xC, |
| Renegr | 0:510bbea7c78e | 19 | 0x4, 0x5, 0x6, 0xD, |
| Renegr | 0:510bbea7c78e | 20 | 0x7, 0x8, 0x9, 0xE, |
| Renegr | 0:510bbea7c78e | 21 | 0xA, 0x0, 0xB, 0xF |
| Renegr | 0:510bbea7c78e | 22 | }; |
| Renegr | 0:510bbea7c78e | 23 | return keytable[r*4+c]; |
| Renegr | 0:510bbea7c78e | 24 | } |
| Renegr | 0:510bbea7c78e | 25 | |
| Renegr | 0:510bbea7c78e | 26 | inline void start() { |
| Renegr | 0:510bbea7c78e | 27 | colBus.output(); |
| Renegr | 0:510bbea7c78e | 28 | colBus = 0xF; |
| Renegr | 0:510bbea7c78e | 29 | } |
| Renegr | 0:510bbea7c78e | 30 | |
| Renegr | 0:510bbea7c78e | 31 | // simple log2, only 4bits needed |
| Renegr | 0:510bbea7c78e | 32 | inline unsigned char _lg2( unsigned char c) { |
| Renegr | 0:510bbea7c78e | 33 | return c&1 ? 0 : c&2 ? 1 : c&4 ? 2 : 3; |
| Renegr | 0:510bbea7c78e | 34 | } |
| Renegr | 0:510bbea7c78e | 35 | |
| Renegr | 0:510bbea7c78e | 36 | inline char pin2Row(PinName pin) { |
| Renegr | 0:510bbea7c78e | 37 | return rowPins[0] == pin ? 0 : rowPins[1] == pin ? 1 : rowPins[2] == pin ? 2 : 3; |
| Renegr | 0:510bbea7c78e | 38 | } |
| Renegr | 0:510bbea7c78e | 39 | |
| Renegr | 0:510bbea7c78e | 40 | BusOut code(LED4, LED3, LED2, LED1); //show binary code of key |
| Renegr | 0:510bbea7c78e | 41 | |
| Renegr | 0:510bbea7c78e | 42 | void checkColumn(PinName pinPressed) { |
| Renegr | 0:510bbea7c78e | 43 | { //debounce |
| Renegr | 0:510bbea7c78e | 44 | DigitalIn in(pinPressed); |
| Renegr | 0:510bbea7c78e | 45 | for (char c=0; c<100; ++c) { |
| Renegr | 0:510bbea7c78e | 46 | if ( !in.read()) { |
| Renegr | 0:510bbea7c78e | 47 | irqFinished=true; |
| Renegr | 0:510bbea7c78e | 48 | return; // key not long enough pressed |
| Renegr | 0:510bbea7c78e | 49 | } |
| Renegr | 0:510bbea7c78e | 50 | wait_us(100); |
| Renegr | 0:510bbea7c78e | 51 | } |
| Renegr | 0:510bbea7c78e | 52 | } |
| Renegr | 0:510bbea7c78e | 53 | // check column |
| Renegr | 0:510bbea7c78e | 54 | DigitalOut p(pinPressed); |
| Renegr | 0:510bbea7c78e | 55 | p = 0x1; |
| Renegr | 0:510bbea7c78e | 56 | colBus.input(); |
| Renegr | 0:510bbea7c78e | 57 | unsigned char col = colBus.read(); |
| Renegr | 0:510bbea7c78e | 58 | if (col) { |
| Renegr | 0:510bbea7c78e | 59 | col = _lg2(col); |
| Renegr | 0:510bbea7c78e | 60 | { // blink to show key pressed |
| Renegr | 0:510bbea7c78e | 61 | code = 0; |
| Renegr | 0:510bbea7c78e | 62 | wait_ms(150); |
| Renegr | 0:510bbea7c78e | 63 | code = 0xF; |
| Renegr | 0:510bbea7c78e | 64 | wait_ms(150); |
| Renegr | 0:510bbea7c78e | 65 | } |
| Renegr | 0:510bbea7c78e | 66 | char row = pin2Row(pinPressed); |
| Renegr | 0:510bbea7c78e | 67 | code = toBinary(row,col); |
| Renegr | 0:510bbea7c78e | 68 | // printf("%d, %d, %c\r\n", row, col, toChar(row,col)); |
| Renegr | 0:510bbea7c78e | 69 | } |
| Renegr | 0:510bbea7c78e | 70 | irqFinished = true; |
| Renegr | 0:510bbea7c78e | 71 | } |
| Renegr | 0:510bbea7c78e | 72 | |
| Renegr | 0:510bbea7c78e | 73 | void trigger27() { |
| Renegr | 0:510bbea7c78e | 74 | checkColumn(p27); |
| Renegr | 0:510bbea7c78e | 75 | } |
| Renegr | 0:510bbea7c78e | 76 | void trigger28() { |
| Renegr | 0:510bbea7c78e | 77 | checkColumn(p28); |
| Renegr | 0:510bbea7c78e | 78 | } |
| Renegr | 0:510bbea7c78e | 79 | void trigger29() { |
| Renegr | 0:510bbea7c78e | 80 | checkColumn(p29); |
| Renegr | 0:510bbea7c78e | 81 | } |
| Renegr | 0:510bbea7c78e | 82 | void trigger30() { |
| Renegr | 0:510bbea7c78e | 83 | checkColumn(p30); |
| Renegr | 0:510bbea7c78e | 84 | } |
| Renegr | 0:510bbea7c78e | 85 | |
| Renegr | 0:510bbea7c78e | 86 | void checkRow() { |
| Renegr | 0:510bbea7c78e | 87 | InterruptIn irqIn27(p27), irqIn28(p28), irqIn29(p29), irqIn30(p30); |
| Renegr | 0:510bbea7c78e | 88 | irqIn27.rise( &trigger27); |
| Renegr | 0:510bbea7c78e | 89 | irqIn28.rise( &trigger28); |
| Renegr | 0:510bbea7c78e | 90 | irqIn29.rise( &trigger29); |
| Renegr | 0:510bbea7c78e | 91 | irqIn30.rise( &trigger30); |
| Renegr | 0:510bbea7c78e | 92 | } |
| Renegr | 0:510bbea7c78e | 93 | |
| Renegr | 0:510bbea7c78e | 94 | int main() { |
| Renegr | 0:510bbea7c78e | 95 | while (1) { |
| Renegr | 0:510bbea7c78e | 96 | start(); |
| Renegr | 0:510bbea7c78e | 97 | irqFinished = false; |
| Renegr | 0:510bbea7c78e | 98 | checkRow(); |
| Renegr | 0:510bbea7c78e | 99 | while (!irqFinished); |
| Renegr | 0:510bbea7c78e | 100 | } |
| Renegr | 0:510bbea7c78e | 101 | } |