#define AO_ADC_RING 32
+/* ao_button.c */
+#ifdef HAS_BUTTON
+void
+ao_p0_isr(void) ao_arch_interrupt(13);
+
+void
+ao_p1_isr(void) ao_arch_interrupt(15);
+
+void
+ao_p2_isr(void);
+
+#define HAS_P2_ISR 1
+
+#endif
+
+void
+ao_button_init(void);
+
+char
+ao_button_get(void) __critical;
+
/* ao_string.c */
void