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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 set_send_alarm(int alarm, uint32_t now, uint32_t next_act_time) {
59 uint32_t sleep_duration = next_act_time - now;
60 if (hardware_alarm_set_target(alarm,
61 make_timeout_time_ms(sleep_duration * 1000)))
62 signal_error_by_blinking();
63 return;
64 }
65
66 void service_sleeps(int alarm, send_t *sleeping_sends, pheap_t *sleeps_heap) {
67 hardware_alarm_cancel(alarm);
68
69 while (1) {
70 uint32_t now = time_s();
71 int32_t act_time = next_scheduled_send(sleeping_sends, sleeps_heap);
72 if (act_time == -1)
73 return;
74 if (act_time > now) {
75 set_send_alarm(alarm, now, act_time);
76 return;
77 }
78 pheap_node_id_t i = ph_remove_head(sleeps_heap, false);
79 send_t *send = &sleeping_sends[i];
80 uint32_t ago = now - send->timestamp;
81 send_report_packet(send->seq, ago);
82 send->send_count++;
83 if (send->send_count < config_resend_count)
84 ph_insert_node(sleeps_heap, i);
85 else
86 ph_free_node(sleeps_heap, i);
87 }
88 }
89
90 void service_queue() {
91 int alarm = hardware_alarm_claim_unused(true);
92 if (alarm == -1)
93 signal_error_by_blinking();
94 hardware_alarm_set_callback(alarm, time_to_send);
95
96 send_t sleeping_sends[PICO_PHEAP_MAX_ENTRIES];
97 pheap_t *sleeps_heap =
98 ph_create(PICO_PHEAP_MAX_ENTRIES, next_send_less_than, sleeping_sends);
99 u16_t seq = 0;
100 while (1) {
101 service_sleeps(alarm, sleeping_sends, sleeps_heap);
102
103 event_t e;
104 queue_remove_blocking(&queue, &e);
105 switch (e.type) {
106 case BUTTONPRESS: {
107 create_send(sleeping_sends, sleeps_heap, e.buttonpress.timestamp, seq++);
108 } break;
109 case SEND: {
110 /* OK, we're awake. Cool. Thanks! (We actually do the sends in the
111 * service_sleeps() call at the top of the loop.) */
112 } break;
113 default:
114 signal_error_by_blinking();
115 }
116 }
117 }
118
119 int main() {
120 stdio_init_all();
121 if (cyw43_arch_init_with_country(CYW43_COUNTRY_USA))
122 signal_error_by_blinking();
123 cyw43_arch_enable_sta_mode();
124 signal(3, 100);
125 if (cyw43_arch_wifi_connect_timeout_ms(config_wifi_ssid, config_wifi_pass,
126 CYW43_AUTH_WPA2_AES_PSK, 90000))
127 signal_error_by_blinking();
128 signal(2, 300);
129
130 queue_init(&queue, sizeof(event_t), 99);
131
132 begin_listening_for_button_press(button_pressed);
133
134 service_queue();
135 }