+/* gpio.c */
+#define GPIO_LED1 0
+#define GPIO_LED2 1
+
+void gpio_init();
+void gpio_set(unsigned char n, unsigned char on);
+
+/* ambient.c */
+void ambient_init();
+extern volatile unsigned char ambient_zone;
+void ambient_adc(uint16_t adc_val);
+
+/* pattern.c */
+void pattern_init();
+void patterns_next_tick();