projects/step-up/buttons.c

   1 #include <avr/io.h>
   2 #include <avr/interrupt.h>
   3 #include <avr/sleep.h>
   4 #include <util/delay.h>
   5 #include <stdlib.h> // for NULL
   6
   7 #include "lights.h"
   8
   9 #define WAKEUP_LIMIT    5       // times 100 ms
  10 #define SHORT_PRESS_MIN 2       // in jiffies (16 Hz ticks)
  11 #define SHORT_PRESS_MAX 5
  12 #define LONG_PRESS_MIN  10
  13 static uint16_t button_start;
  14 static unsigned char prev_state;
  15
  16 void status_led_on_off(unsigned char mode)
  17 {
  18         if (mode)
  19                 PORTB |= _BV(PORTB1);
  20         else
  21                 PORTB &= ~_BV(PORTB1);
  22 }
  23
  24 void init_buttons()
  25 {
  26         DDRB &= ~_BV(DDB0);
  27         DDRB |= _BV(DDB1);
  28         PORTB |= _BV(PORTB0); // enable internal pull-up
  29         PORTB &= ~_BV(PORTB1); // status led off
  30         GIMSK &= ~_BV(PCIE); // disable pin-change IRQs
  31         PCMSK = 0; // disable pin-change IRQs on all pins of port B
  32
  33         button_start = 0;
  34         prev_state   = 0;
  35 }
  36
  37 void susp_buttons()
  38 {
  39         DDRB &= ~(_BV(DDB0)); // set as input
  40         PORTB |= _BV(PORTB0);  // enable internal pull-up
  41         PORTB &= ~_BV(PORTB1); // set to zero
  42
  43         GIMSK |= _BV(PCIE);
  44
  45         PCMSK = _BV(PCINT0);
  46                 // disable pin-change IRQs on all pins except PB1
  47 }
  48
  49 void timer_check_buttons()
  50 {
  51         unsigned char cur = !(PINB & _BV(PINB0));
  52         unsigned char prev = prev_state;
  53
  54         prev_state = cur;
  55
  56         if (cur && !prev) {                   // --- just pressed ---
  57                 button_start = jiffies;
  58                 // set_status_led(button, NULL);
  59
  60         } else if (cur && prev) {           // --- is still pressed ---
  61                 uint16_t duration = jiffies - button_start;
  62
  63                 if (duration > LONG_PRESS_MIN) {
  64                         long_press_start();
  65                                 // acknowledge long press
  66                 }
  67         } else if (!cur && prev) {            // --- just released ---
  68                 uint16_t duration = jiffies - button_start;
  69
  70                 if (duration >= SHORT_PRESS_MIN && duration < SHORT_PRESS_MAX) {
  71                         short_press();
  72                 } else if (duration > LONG_PRESS_MIN) {
  73                         // set_status_led(button, NULL);
  74                         long_press();
  75                 }
  76                 // ignore other button-press durations
  77         }
  78 }
  79
  80 #if 0
  81 static void handle_brake(unsigned char cur, unsigned char prev)
  82 {
  83         if (cur && !prev) {                   // --- just pressed ---
  84                 button_start[2] = jiffies;
  85         } else if (!cur && prev) {            // --- just released ---
  86                 button_start[2] = jiffies;
  87         } else {                              // --- no change ---
  88                 uint16_t duration = jiffies - button_start[2];
  89
  90                 if (duration > 6) {
  91                         if (cur) {
  92                                 if (button_state.brake_working
  93                                         && !button_state.brake_reported) {
  94                                         button_state.brake_reported = 1;
  95                                         brake_on();
  96                                 }
  97                         } else {
  98                                 button_state.brake_working = 1;
  99                                 if (button_state.brake_reported) {
 100                                         button_state.brake_reported = 0;
 101                                         brake_off();
 102                                 }
 103                         }
 104                         button_start[2] = jiffies - 7; // avoid overflow
 105                 }
 106         }
 107 }
 108 #endif
 109
 110 unsigned char buttons_wait_for_release()
 111 {
 112         uint16_t wake_count = 0;
 113         unsigned char pin;
 114
 115         do {
 116                 if (wake_count++ > WAKEUP_LIMIT)
 117                         status_led_on_off(1); // inform the user
 118
 119                 _delay_ms(100);
 120
 121                 pin = PINB & _BV(PINB0);
 122         } while (!(pin & _BV(PINB0)));
 123
 124         status_led_on_off(0);
 125
 126         return wake_count > WAKEUP_LIMIT;
 127 }
 128
 129 ISR(PCINT0_vect)
 130 {
 131         // empty - let it wake us from sleep, but do nothing else
 132 }
 133