main.c

   1 #include <stdlib.h>
   2 #include <stdio.h>
   3 #include <wiringPi.h>
   4 #include <time.h>
   5 #include "config.h"
   6
   7 #define COIN_BUTTON 7 //physically pin 7
   8 #define SYNC_PIN 4 //physically pin 16
   9
  10 configuration config;
  11 int expires = -1;
  12 int one_second_ago = 0;
  13 int switch_state; //Keeps track of what state the software thinks the switch should be in
  14
  15 void init_gpio()
  16 {
  17   wiringPiSetup();
  18   pinMode(COIN_BUTTON, INPUT);
  19   pinMode(SYNC_PIN, INPUT);
  20   pullUpDnControl(COIN_BUTTON, PUD_UP);
  21   pullUpDnControl(SYNC_PIN, PUD_UP);
  22 }
  23
  24 void pulse_switch()
  25 {
  26   delay(config.sync_switch_delay); //wait
  27   // do the biz
  28 }
  29
  30 int validate_switch_state()
  31 {
  32   if(config.sync_switch == 0 || digitalRead(SYNC_PIN) == switch_state)
  33     return 1;
  34
  35   printf("Sync pin is not what I expected, attempting to switch signal\n");
  36   pulse_switch();
  37
  38   return digitalRead(SYNC_PIN) == switch_state;
  39 }
  40
  41 int now()
  42 {
  43   return (unsigned)time(NULL);
  44 }
  45
  46 int time_over()
  47 {
  48   if(one_second_ago != now() && expires != -1)
  49   {
  50     printf("You have %d seconds remaining\n", expires - now());
  51     one_second_ago = now();
  52   }
  53
  54   if(expires != -1 && expires <= now())
  55   {
  56     printf("It's all ogre now\n");
  57     expires = -1;
  58     switch_state = 1 - switch_state;
  59     return 1;
  60   }
  61
  62   return expires == -1;
  63 }
  64
  65 int read_button()
  66 {
  67   if(digitalRead(COIN_BUTTON) == LOW)
  68   {
  69     if(config.external_timer != 1)
  70     {
  71       printf("Nice! I just added %d to your time.\n", config.credit_value);
  72
  73       //Increment timer
  74       if(expires == -1) //Initial credit, set the expiry to now plus time
  75       {
  76           expires = now() + config.credit_value;
  77       } else { //expiry already set, simply extend by time
  78           expires += config.credit_value;
  79       }
  80
  81       //wait for button to be released
  82       while(digitalRead(COIN_BUTTON) == LOW)
  83       {
  84          //I don't see this happening, but in principle if the button is held down
  85          //It would be possible to stop the switch happening after time runs out
  86          //So we must check for that here.
  87          if(time_over())
  88            break;
  89
  90          delay(10);
  91       }
  92     }
  93
  94     // Flip switch state
  95     // But only if we are in the default state (IE waiting for a credit)
  96     if(config.default_switch_state == switch_state)
  97     {
  98       printf("Changing internal switch state from %d\n", switch_state);
  99       switch_state = 1 - switch_state;
 100       printf("Switch state is now %d\n", switch_state);
 101     }
 102
 103     return 1;
 104   }
 105
 106   return 0;
 107 }
 108
 109 int main (void)
 110 {
 111   printf("hdmi-switcher %s\n", VERSION);
 112   init_config(&config);
 113   init_gpio();
 114   switch_state = config.default_switch_state;
 115   printf ("Short pin 7 and 9 to increment timer.\n") ;
 116
 117   while(1)
 118   {
 119     if(validate_switch_state() == 0)
 120     {
 121       printf("Unable to switch video signal. Exiting.\n");
 122       exit(1);
 123     }
 124
 125     read_button();
 126     //I don't really need to call this here but I'm doing it to see output.
 127     time_over();
 128     delay(10);
 129   }
 130
 131   exit(0);
 132 }