+/*
+ * A/D data is stored in a ring, with the next sample to be written
+ * at ao_adc_head
+ */
+extern volatile __xdata struct ao_adc ao_adc_ring[ADC_RING];
+extern volatile __data uint8_t ao_adc_head;
+
+/* Trigger a conversion sequence (called from the timer interrupt) */
+void
+ao_adc_poll(void);
+
+/* Suspend the current task until another A/D sample is converted */
+void
+ao_adc_sleep(void);
+
+/* Get a copy of the last complete A/D sample set */
+void
+ao_adc_get(__xdata struct ao_adc *packet);
+
+/* The A/D interrupt handler */
+void
+ao_adc_isr(void) interrupt 1;
+
+/* Initialize the A/D converter */
+void
+ao_adc_init(void);
+
+/*
+ * ao_beep.c
+ */
+
+/*
+ * Various pre-defined beep frequencies
+ *
+ * frequency = 1/2 (24e6/32) / beep
+ */
+
+#define AO_BEEP_LOW 150 /* 2500Hz */
+#define AO_BEEP_MID 94 /* 3989Hz */
+#define AO_BEEP_HIGH 75 /* 5000Hz */
+#define AO_BEEP_OFF 0 /* off */
+
+#define AO_BEEP_g 240 /* 1562.5Hz */
+#define AO_BEEP_gs 227 /* 1652Hz (1655Hz) */
+#define AO_BEEP_aa 214 /* 1752Hz (1754Hz) */
+#define AO_BEEP_bbf 202 /* 1856Hz (1858Hz) */
+#define AO_BEEP_bb 190 /* 1974Hz (1969Hz) */
+#define AO_BEEP_cc 180 /* 2083Hz (2086Hz) */
+#define AO_BEEP_ccs 170 /* 2205Hz (2210Hz) */
+#define AO_BEEP_dd 160 /* 2344Hz (2341Hz) */
+#define AO_BEEP_eef 151 /* 2483Hz (2480Hz) */
+#define AO_BEEP_ee 143 /* 2622Hz (2628Hz) */
+#define AO_BEEP_ff 135 /* 2778Hz (2784Hz) */
+#define AO_BEEP_ffs 127 /* 2953Hz (2950Hz) */
+#define AO_BEEP_gg 120 /* 3125Hz */
+#define AO_BEEP_ggs 113 /* 3319Hz (3311Hz) */
+#define AO_BEEP_aaa 107 /* 3504Hz (3508Hz) */
+#define AO_BEEP_bbbf 101 /* 3713Hz (3716Hz) */
+#define AO_BEEP_bbb 95 /* 3947Hz (3937Hz) */
+#define AO_BEEP_ccc 90 /* 4167Hz (4171Hz) */
+#define AO_BEEP_cccs 85 /* 4412Hz (4419Hz) */
+#define AO_BEEP_ddd 80 /* 4688Hz (4682Hz) */
+#define AO_BEEP_eeef 76 /* 4934Hz (4961Hz) */
+#define AO_BEEP_eee 71 /* 5282Hz (5256Hz) */
+#define AO_BEEP_fff 67 /* 5597Hz (5568Hz) */
+#define AO_BEEP_fffs 64 /* 5859Hz (5899Hz) */
+#define AO_BEEP_ggg 60 /* 6250Hz */
+
+/* Set the beeper to the specified tone */
+void
+ao_beep(uint8_t beep);
+
+/* Turn on the beeper for the specified time */
+void
+ao_beep_for(uint8_t beep, uint16_t ticks);
+
+/* Initialize the beeper */
+void
+ao_beep_init(void);
+
+/*
+ * ao_led.c
+ */
+
+#define AO_LED_NONE 0
+#define AO_LED_GREEN 1
+#define AO_LED_RED 2
+
+/* Turn on the specified LEDs */
+void
+ao_led_on(uint8_t colors);
+
+/* Turn off the specified LEDs */
+void
+ao_led_off(uint8_t colors);