press_pile_t *create_press_pile();
-void create_press(press_pile_t *pp, uint32_t timestamp, u16_t seq);
+/* Adds this press to the pile.
+ * Copies the contents of `press`. */
+void add_press(press_pile_t *pp, press_t *press);
/* When do we next need to send something (in seconds since boot)?
* Returns -1 if there's nothing pending. */