1 files changed, 129 insertions, 0 deletions
diff --git a/src/avr/ao_adc_avr.c b/src/avr/ao_adc_avr.c
new file mode 100644
index 00000000..5afced74
--- /dev/null
+++ b/src/avr/ao_adc_avr.c
@@ -0,0 +1,129 @@
+/*
+ * Copyright © 2011 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include "ao.h"
+
+volatile __xdata struct ao_adc	ao_adc_ring[AO_ADC_RING];
+volatile __data uint8_t		ao_adc_head;
+
+const uint8_t	adc_channels[AO_LOG_TELESCIENCE_NUM_ADC] = {
+	0x00,
+	0x01,
+	0x04,
+	0x05,
+	0x06,
+	0x07,
+	0x20,
+	0x21,
+	0x22,
+	0x23,
+	0x24,
+	0x25,
+};
+
+static uint8_t	ao_adc_channel;
+
+#define ADC_CHANNEL_LOW(c)	(((c) & 0x1f) << MUX0)
+#define ADC_CHANNEL_HIGH(c)	((((c) & 0x20) >> 5) << MUX5)
+
+#define ADCSRA_INIT	((1 << ADEN) |		/* Enable ADC */ 		\
+			 (0 << ADATE) |		/* No auto ADC trigger */ 	\
+			 (1 << ADIF) |		/* Clear interrupt */		\
+			 (0 << ADIE) |		/* Enable interrupt */		\
+			 (6 << ADPS0))		/* Prescale clock by 64 */
+
+#define ADCSRB_INIT	((0 << ADHSM) |		/* No high-speed mode */ \
+			 (0 << ACME) |		/* Some comparitor thing */ \
+			 (2 << ADTS0))		/* Free running mode (don't care) */
+
+static void
+ao_adc_start(void)
+{
+	uint8_t	channel = adc_channels[ao_adc_channel];
+	ADMUX = ((0 << REFS1) |				/* AVcc reference */
+		 (1 << REFS0) |				/* AVcc reference */
+		 (1 << ADLAR) |				/* Left-shift results */
+		 (ADC_CHANNEL_LOW(channel)));		/* Select channel */
+
+	ADCSRB = (ADCSRB_INIT |
+		  ADC_CHANNEL_HIGH(channel));		/* High channel bit */
+
+	ADCSRA = (ADCSRA_INIT |
+		  (1 << ADSC) |
+		  (1 << ADIE));				/* Start conversion */
+}
+
+ISR(ADC_vect)
+{
+	uint16_t	value;
+
+	/* Must read ADCL first or the value there will be lost */
+	value = ADCL;
+	value |= (ADCH << 8);
+	ao_adc_ring[ao_adc_head].adc[ao_adc_channel] = value;
+	if (++ao_adc_channel < AO_TELESCIENCE_NUM_ADC)
+		ao_adc_start();
+	else {
+		ADCSRA = ADCSRA_INIT;
+		ao_adc_ring[ao_adc_head].tick = ao_time();
+		ao_adc_head = ao_adc_ring_next(ao_adc_head);
+		ao_wakeup((void *) &ao_adc_head);
+		ao_cpu_sleep_disable = 0;
+	}
+}
+
+void
+ao_adc_poll(void)
+{
+	ao_cpu_sleep_disable = 1;
+	ao_adc_channel = 0;
+	ao_adc_start();
+}
+
+void
+ao_adc_get(__xdata struct ao_adc *packet)
+{
+	uint8_t	i = ao_adc_ring_prev(ao_adc_head);
+	memcpy(packet, (void *) &ao_adc_ring[i], sizeof (struct ao_adc));
+}
+
+static void
+ao_adc_dump(void) __reentrant
+{
+	static __xdata struct ao_adc	packet;
+	uint8_t i;
+	ao_adc_get(&packet);
+	printf("tick: %5u",  packet.tick);
+	for (i = 0; i < AO_TELESCIENCE_NUM_ADC; i++)
+		printf (" %2d: %5u", i, packet.adc[i]);
+	printf ("\n");
+}
+
+__code struct ao_cmds ao_adc_cmds[] = {
+	{ ao_adc_dump,	"a\0Display current ADC values" },
+	{ 0, NULL },
+};
+
+void
+ao_adc_init(void)
+{
+	DIDR0 = 0xf3;
+	DIDR2 = 0x3f;
+	ADCSRB = ADCSRB_INIT;
+	ADCSRA = ADCSRA_INIT;
+	ao_cmd_register(&ao_adc_cmds[0]);
+}