main.c

   1 #include <stdlib.h>
   2 #include <stdio.h>
   3 #include <string.h>
   4 #include <wiringPi.h>
   5 #include <time.h>
   6 #include "config.h"
   7
   8 #define COIN_BUTTON 7 //physically pin 7
   9 #define SYNC_PIN 4 //physically pin 16
  10
  11 configuration config;
  12 int expires = -1;
  13 int one_second_ago = 0;
  14 int switch_state; //Keeps track of what state the software thinks the switch should be in
  15
  16 void init_gpio()
  17 {
  18   wiringPiSetup();
  19   pinMode(COIN_BUTTON, INPUT);
  20   pinMode(SYNC_PIN, INPUT);
  21   pullUpDnControl(COIN_BUTTON, PUD_UP);
  22   pullUpDnControl(SYNC_PIN, PUD_UP);
  23 }
  24
  25 void pulse_switch()
  26 {
  27   delay(config.sync_switch_delay); //wait
  28   // do the biz
  29 }
  30
  31 int validate_switch_state()
  32 {
  33   if(config.sync_switch == 0 || digitalRead(SYNC_PIN) == switch_state)
  34     return 1;
  35
  36   printf("Sync pin is not what I expected, attempting to switch signal\n");
  37   pulse_switch();
  38
  39   return digitalRead(SYNC_PIN) == switch_state;
  40 }
  41
  42 int now()
  43 {
  44   return (unsigned)time(NULL);
  45 }
  46
  47 int time_over()
  48 {
  49   if(one_second_ago != now() && expires != -1)
  50   {
  51     printf("You have %d seconds remaining\n", expires - now());
  52     one_second_ago = now();
  53   }
  54
  55   if(expires != -1 && expires <= now())
  56   {
  57     printf("It's all ogre now\n");
  58     expires = -1;
  59     switch_state = 1 - switch_state;
  60     return 1;
  61   }
  62
  63   return expires == -1;
  64 }
  65
  66 int read_button()
  67 {
  68   if(digitalRead(COIN_BUTTON) == LOW)
  69   {
  70     // Don't do anything until button is released
  71     while(digitalRead(COIN_BUTTON) == LOW)
  72     {
  73       //I don't see this happening, but in principle if the button is held down
  74       //It would be possible to stop the switch happening after time runs out
  75       //So we must check for that here.
  76       time_over();
  77       delay(10);
  78     }
  79
  80     // Flip internal switch state, but only if we are in the default state
  81     // i.e., waiting for a credit
  82     if(config.default_switch_state == switch_state)
  83     {
  84       printf("Changing internal switch state from %d\n", switch_state);
  85       switch_state = 1 - switch_state;
  86       printf("Switch state is now %d\n", switch_state);
  87     }
  88
  89     if(config.external_timer != 1)
  90     {
  91       printf("Nice! I just added %d to your time.\n", config.credit_value);
  92
  93       //Increment timer
  94       if(expires == -1) //Initial credit, set the expiry to now plus time
  95       {
  96           expires = now() + config.credit_value;
  97       } else { //expiry already set, simply extend by time
  98           expires += config.credit_value;
  99       }
 100
 101       //wait for button to be released
 102       while(digitalRead(COIN_BUTTON) == LOW)
 103       {
 104          //I don't see this happening, but in principle if the button is held down
 105          //It would be possible to stop the switch happening after time runs out
 106          //So we must check for that here.
 107          if(time_over())
 108            break;
 109
 110          delay(10);
 111       }
 112     }
 113
 114     return 1;
 115   }
 116
 117   return 0;
 118 }
 119
 120 int main (int argc, char *argv[])
 121 {
 122   if(argc == 2 && strcmp("version", argv[1]) == 0)
 123   {
 124     printf("hdmi-switcher %s\n", VERSION);
 125     exit(1);
 126   }
 127
 128   init_config(&config);
 129   init_gpio();
 130   switch_state = config.default_switch_state;
 131   printf ("Short pin 7 and 9 to increment timer.\n") ;
 132
 133   while(1)
 134   {
 135     if(validate_switch_state() == 0)
 136     {
 137       printf("Unable to switch video signal. Exiting.\n");
 138       exit(1);
 139     }
 140
 141     read_button();
 142     //I don't really need to call this here but I'm doing it to see output.
 143     time_over();
 144     delay(10);
 145   }
 146
 147   exit(0);
 148 }