+extern u16_t config_this_tattler_identity;
+
+/* Which GPIO pin is the button connected to?
+ * The button should span this pin and ground, connecting this pin to ground
+ * when pressed.
+ * https://projects.raspberrypi.org/en/projects/introduction-to-the-pico/10
+ * recommends pins 18, 22, or 28. */
+extern uint config_button_pin;
+
+/* Don't bother reporting each separate button press when it is pressed many
+ * times in short succession. (We also use this to de-bounce. :) */
+extern u32_t config_minimum_seconds_between_button_presses;
+
+/* Send each report multiple times. */
+extern uint config_resend_count;