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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 create_send(sleeping_sends, sleeps_heap, e.buttonpress.timestamp, seq++);
104 } break;
105 case SEND: {
106 /* OK, we're awake. Cool. Thanks! (We actually do the sends in the
107 * service_sleeps() call at the top of the loop.) */
108 } break;
109 default:
110 signal_error_by_blinking();
111 }
112 }
113 }
114
115 int main() {
116 stdio_init_all();
117 if (cyw43_arch_init_with_country(CYW43_COUNTRY_USA))
118 signal_error_by_blinking();
119 cyw43_arch_enable_sta_mode();
120 signal(3, 100);
121 if (cyw43_arch_wifi_connect_timeout_ms(config_wifi_ssid, config_wifi_pass,
122 CYW43_AUTH_WPA2_AES_PSK, 90000))
123 signal_error_by_blinking();
124 signal(2, 300);
125
126 queue_init(&queue, sizeof(event_t), 99);
127
128 begin_listening_for_button_press(button_pressed);
129
130 service_queue();
131 }