-u32_t config_minimum_seconds_between_button_presses = 1;
-
-/* Send each report multiple times. */
-uint config_resend_count = 5;
+const u32_t config_minimum_seconds_between_button_presses = 1;
+
+/* Send each report multiple times. Re-sends are sent with exponential delay:
+ * #1 sent immediately
+ * #2 after 1 seconds
+ * #3 after 2 seconds
+ * #4 after 4 seconds
+ * #5 after 8 seconds
+ * ...
+ * #11 after 8 minutes
+ * #12 after 17 minutes
+ * #13 after 34 minutes
+ * #14 after 68 minutes
+ * #15 after 2 hours
+ * #16 after 4 hours
+ * #17 after 9 hours
+ * etc.
+ * This provides some robustness against network outages, automatically
+ * replaying the log periodically to be collected after connectivity
+ * is restored.
+ *
+ * Values above 17 are currently not recommended because the current
+ * wire format uses a 16-bit field for a duration in seconds, which wraps
+ * at 18 hours.
+ * */
+const uint config_resend_count = 16;