1 | #ifndef F_CPU
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2 | #define F_CPU 8000000 // processor clock frequency 8Mhz
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3 | #warning kein F_CPU definiert
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4 | #endif
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5 |
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6 |
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7 | /****************************************************************************/
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8 | /* */
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9 | /* Programm LED und Taster */
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10 | /* */
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11 | /****************************************************************************/
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12 |
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13 | // ----------------------------------------------------------------------------
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14 | // INCLUDES
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15 | // ----------------------------------------------------------------------------
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16 |
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17 | #include <stdint.h>
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18 | #include <avr/io.h>
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19 | #include <avr/interrupt.h>
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20 | #include <util/delay.h>
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21 | #include <inttypes.h>
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22 |
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23 |
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24 |
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25 | // ----------------------------------------------------------------------------
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26 | // DEFINES
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27 | // ----------------------------------------------------------------------------
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28 | #define Taster PB0 //Pin des Tasters
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29 | #define LED PB1 //Pin der LED
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30 |
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31 | //für die Entprellunsroutine
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32 | #define KEY_DDR DDRB
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33 | #define KEY_PORT PORTB
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34 | #define KEY_PIN PINB
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35 | #define KEY0 0
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36 | #define KEY1 1
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37 | #define KEY2 2
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38 | #define ALL_KEYS (1<<KEY0 | 1<<KEY1 | 1<<KEY2)
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39 |
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40 | #define REPEAT_MASK (1<<KEY1 | 1<<KEY2) // repeat: key1, key2
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41 | #define REPEAT_START 50 // after 500ms
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42 | #define REPEAT_NEXT 20 // every 200ms
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43 |
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44 |
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45 | // ----------------------------------------------------------------------------
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46 | // Funktionsdeklarationen
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47 | // ----------------------------------------------------------------------------
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48 | void init(void);
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49 | uint8_t get_key_press( uint8_t key_mask );
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50 |
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51 |
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52 | // ----------------------------------------------------------------------------
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53 | // globale Variablen die durch Interrupts verändert werden
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54 | // ----------------------------------------------------------------------------
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55 | volatile uint8_t key_state; // debounced and inverted key state:
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56 | // bit = 1: key pressed
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57 | volatile uint8_t key_press; // key press detect
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58 |
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59 | volatile uint8_t key_rpt; // key long press and repeat
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60 |
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61 |
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62 | // ----------------------------------------------------------------------------
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63 | // globale Variablen des Programms
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64 | // ----------------------------------------------------------------------------
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65 |
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66 |
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67 | //Timer0 Overflow Interrupt
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68 | ISR( TIMER0_OVF_vect ) // every 10ms
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69 | {
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70 | static uint8_t ct0, ct1, rpt;
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71 | uint8_t i;
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72 |
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73 | TCNT0 = (uint8_t)(int16_t)-(F_CPU / 1024 * 10e-3 + 0.5); // preload for 10ms
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74 |
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75 | i = key_state ^ ~KEY_PIN; // key changed ?
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76 | ct0 = ~( ct0 & i ); // reset or count ct0
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77 | ct1 = ct0 ^ (ct1 & i); // reset or count ct1
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78 | i &= ct0 & ct1; // count until roll over ?
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79 | key_state ^= i; // then toggle debounced state
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80 | key_press |= key_state & i; // 0->1: key press detect
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81 |
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82 | if( (key_state & REPEAT_MASK) == 0 ) // check repeat function
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83 | rpt = REPEAT_START; // start delay
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84 | if( --rpt == 0 ){
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85 | rpt = REPEAT_NEXT; // repeat delay
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86 | key_rpt |= key_state & REPEAT_MASK;
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87 | }
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88 | }
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89 |
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90 | //Das Hauptprogramm
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91 | int main()
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92 | {
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93 | //variablen für das Programm
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94 | char ledStatus=0;
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95 |
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96 | //Initialisieren der Ports über die Funktion init()
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97 | init();
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98 |
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99 | while(1)
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100 |
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101 |
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102 | //Zustand des Tasters abfragen mit Entprellfunktion
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103 | if( (get_key_press( 1<<KEY0 )&&ledStatus==0)){
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104 | PORTB &=~ (1 << LED); //LED anschalten
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105 | ledStatus=1;
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106 | }
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107 |
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108 | else if ( get_key_press( 1<<KEY0 )){
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109 | PORTB |= (1 << LED); //LED ausschalten
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110 | ledStatus=0;
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111 | }
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112 |
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113 | }
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114 |
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115 |
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116 |
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117 | // ----------------------------------------------------------------------------
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118 | // Funktionen
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119 | // ----------------------------------------------------------------------------
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120 |
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121 | /*Funktion zum Initialisierein des µC*/
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122 |
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123 | void init(void) {
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124 | // ------------------------------------------------------------------------
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125 | // PORTB konfigurieren
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126 | //
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127 | // B0 --> Eingang für Taster, active-low
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128 | // B1 --> Ausgang für LED, active-low
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129 | // ------------------------------------------------------------------------
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130 |
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131 | DDRB = 0x00; //Datenrichtungsregister zunächst alle Eingang
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132 | DDRB |= (1 << DDB1); //PB1 als Ausgang schalten für LED
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133 | PORTB = (1 << PB0) | (1 << PB1); //an PB0 interne Pullup aktiviert (Eingang), LED anfangs ausschalten
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134 |
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135 | //-------------------------------------------------------------------------
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136 | //Timer konfigurieren
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137 | //-------------------------------------------------------------------------
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138 | TCCR0 = (1<<CS02)|(1<<CS00); // divide by 1024
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139 | TIMSK = 1<<TOIE0; // enable timer interrupt
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140 | sei(); //setzt globales Interrupt enable
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141 | }
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142 |
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143 |
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144 |
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145 | /************************************************************************/
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146 | /* */
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147 | /* Debouncing 8 Keys */
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148 | /* Sampling 4 Times */
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149 | /* With Repeat Function */
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150 | /* */
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151 | /* Author: Peter Dannegger */
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152 | /* danni@specs.de */
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153 | /* */
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154 | /************************************************************************/
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155 |
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156 |
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157 |
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158 | ///////////////////////////////////////////////////////////////////
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159 | //
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160 | // check if a key has been pressed. Each pressed key is reported
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161 | // only once
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162 | //
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163 | uint8_t get_key_press( uint8_t key_mask )
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164 | {
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165 | cli(); // read and clear atomic !
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166 | key_mask &= key_press; // read key(s)
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167 | key_press ^= key_mask; // clear key(s)
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168 | sei();
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169 | return key_mask;
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170 | }
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