+enum event_type { BUTTONPRESS };
+typedef struct {
+ enum event_type type;
+ union {
+ struct {
+ uint32_t timestamp;
+ } buttonpress;
+ };
+} event_t;
+
+queue_t queue;
+
+uint32_t time_s() { return time_us_64() / 1000000ul; }
+
+static void button_pressed() {
+ /* This runs in interrupt context; don't linger. */
+ static uint64_t last_button_press_time = 0;
+ uint32_t now = time_s();
+ uint32_t time_since_last_press = now - last_button_press_time;
+ if (time_since_last_press >= config_minimum_seconds_between_button_presses) {
+ last_button_press_time = now;
+ event_t e;
+ e.type = BUTTONPRESS;
+ e.buttonpress.timestamp = now;
+ /* We don't check for failure (full queue) here because there's not much to
+ * be done about it. */
+ queue_try_add(&queue, &e);
+ }
+}