git.scottworley.com Git - tattlekey/blob - client/tattlekey.c

   1 #include "pico/cyw43_arch.h"
   2 #include "pico/stdlib.h"
   3 #include "pico/util/pheap.h"
   4 #include "pico/util/queue.h"
   5
   6 #include "blink.h"
   7 #include "button.h"
   8 #include "config.h"
   9 #include "net.h"
  10 #include "sends.h"
  11
  12 enum event_type { BUTTONPRESS, SEND };
  13 typedef struct {
  14   enum event_type type;
  15   union {
  16     struct {
  17       uint32_t timestamp;
  18     } buttonpress;
  19   };
  20 } event_t;
  21
  22 queue_t queue;
  23
  24 uint32_t time_s() { return time_us_64() / 1000000ul; }
  25
  26 /* Often we don't bother checking for failure (full queue) because
  27  *   1. The best thing to do in this unfortunate situation is to blithely
  28  *      continue, dropping some events; continuing is better than stopping.
  29  *   2. Neither interrupt context nor queue-processing context can block
  30  *      until space is available, or even sit around & blink the LED to
  31  *      signal a problem.
  32  * (We also get a bit of type safety by taking event_t* rather than void*.) */
  33 static void queue_try_add_ignoring_errors(queue_t *q, event_t *e) {
  34   queue_try_add(q, e);
  35 }
  36
  37 static void button_pressed() {
  38   /* This runs in interrupt context; don't linger.  */
  39   static uint64_t last_button_press_time = 0;
  40   uint32_t now = time_s();
  41   uint32_t time_since_last_press = now - last_button_press_time;
  42   if (time_since_last_press >= config_minimum_seconds_between_button_presses) {
  43     last_button_press_time = now;
  44     event_t e;
  45     e.type = BUTTONPRESS;
  46     e.buttonpress.timestamp = now;
  47     queue_try_add_ignoring_errors(&queue, &e);
  48   }
  49 }
  50
  51 static void time_to_send(uint _) {
  52   /* This runs in interrupt context; don't linger.  */
  53   event_t e;
  54   e.type = SEND;
  55   queue_try_add_ignoring_errors(&queue, &e);
  56 }
  57
  58 void service_sleeps(int alarm, send_t *sleeping_sends, pheap_t *sleeps_heap) {
  59   hardware_alarm_cancel(alarm);
  60
  61   while (1) {
  62     uint32_t now = time_s();
  63     pheap_node_id_t i = ph_peek_head(sleeps_heap);
  64     if (i == 0)
  65       return;
  66     send_t *send = &sleeping_sends[i];
  67     if (next_send(send) > now) {
  68       uint32_t sleep_duration = next_send(send) - now;
  69       if (hardware_alarm_set_target(
  70               alarm, make_timeout_time_ms(sleep_duration * 1000)))
  71         signal_error_by_blinking();
  72       return;
  73     }
  74     if (ph_remove_head(sleeps_heap, false) != i)
  75       signal_error_by_blinking();
  76     uint32_t ago = now - send->timestamp;
  77     send_report(send->seq, ago);
  78     send->send_count++;
  79     if (send->send_count < config_resend_count)
  80       ph_insert_node(sleeps_heap, i);
  81     else
  82       ph_free_node(sleeps_heap, i);
  83   }
  84 }
  85
  86 void service_queue() {
  87   int alarm = hardware_alarm_claim_unused(true);
  88   if (alarm == -1)
  89     signal_error_by_blinking();
  90   hardware_alarm_set_callback(alarm, time_to_send);
  91
  92   send_t sleeping_sends[PICO_PHEAP_MAX_ENTRIES];
  93   pheap_t *sleeps_heap =
  94       ph_create(PICO_PHEAP_MAX_ENTRIES, next_send_less_than, sleeping_sends);
  95   u16_t seq = 0;
  96   while (1) {
  97     service_sleeps(alarm, sleeping_sends, sleeps_heap);
  98
  99     event_t e;
 100     queue_remove_blocking(&queue, &e);
 101     switch (e.type) {
 102     case BUTTONPRESS: {
 103       pheap_node_id_t i = ph_new_node(sleeps_heap);
 104       if (i == 0) {
 105         /* TODO: Don't drop new presses just because sleeps_heap is full of old
 106          * presses. */
 107         break;
 108       }
 109       sleeping_sends[i].timestamp = e.buttonpress.timestamp;
 110       sleeping_sends[i].seq = seq++;
 111       sleeping_sends[i].send_count = 0;
 112       ph_insert_node(sleeps_heap, i);
 113     } break;
 114     case SEND: {
 115       /* OK, we're awake. Cool. Thanks! (We actually do the sends in the
 116        * service_sleeps() call at the top of the loop.)  */
 117     } break;
 118     default:
 119       signal_error_by_blinking();
 120     }
 121   }
 122 }
 123
 124 int main() {
 125   stdio_init_all();
 126   if (cyw43_arch_init_with_country(CYW43_COUNTRY_USA))
 127     signal_error_by_blinking();
 128   cyw43_arch_enable_sta_mode();
 129   signal(3, 100);
 130   if (cyw43_arch_wifi_connect_timeout_ms(config_wifi_ssid, config_wifi_pass,
 131                                          CYW43_AUTH_WPA2_AES_PSK, 90000))
 132     signal_error_by_blinking();
 133   signal(2, 300);
 134
 135   queue_init(&queue, sizeof(event_t), 99);
 136
 137   begin_listening_for_button_press(button_pressed);
 138
 139   service_queue();
 140 }