From d80377ee196a974d557abe0cbb8b36fe3e8ae1a5 Mon Sep 17 00:00:00 2001
From: Bart Van Der Meerssche <bart.vandermeerssche@flukso.net>
Date: Wed, 29 Dec 2010 14:08:20 +0100
Subject: [PATCH] avr: set up the ADC with bandgap as a reference

---
 mote/v2/avr/main.c   | 15 ++++++++++++++-
 mote/v2/avr/makefile |  3 +++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/mote/v2/avr/main.c b/mote/v2/avr/main.c
index 37199ca..208b7aa 100644
--- a/mote/v2/avr/main.c
+++ b/mote/v2/avr/main.c
@@ -223,6 +223,18 @@ void setup_pulse_input(void)
 	EIMSK = (1<<INT0) | (1<<INT1);
 }
 
+void setup_adc(void)
+{
+	// disable digital input cicuitry on ADCx pins to reduce leakage current
+	DIDR0 |= (1<<ADC5D) | (1<<ADC4D) | (1<<ADC3D) | (1<<ADC2D) | (1<<ADC1D) | (1<<ADC0D);
+
+	// select VBG as reference for ADC
+	ADMUX |= (1<<REFS1) | (1<<REFS0);
+	// ADC prescaler set to 32 => 3686.4kHz / 32 = 115.2kHz (DS p.258)
+	ADCSRA |= (1<<ADPS2) | (1<<ADPS0);
+	// enable ADC and start a first ADC conversion
+	ADCSRA |= (1<<ADEN) | (1<<ADSC);
+}
 
 void setup_timer1(void)
 {
@@ -298,10 +310,11 @@ int main(void)
 	//PORTD |= (1<<PD5);
 
 	setup_datastructs();
+	setup_adc();
 	setup_timer1();
 	setup_pulse_input();
 	setup_analog_comparator();
-		
+	
 	// initialize the CTRL buffers
 	ctrlInit();
 	// initialize the UART hardware and buffers
diff --git a/mote/v2/avr/makefile b/mote/v2/avr/makefile
index 6b1a08d..2113f14 100644
--- a/mote/v2/avr/makefile
+++ b/mote/v2/avr/makefile
@@ -115,6 +115,9 @@ CSTANDARD = -std=gnu99
 # Place -D or -U options here
 CDEFS = -DF_CPU=$(F_CPU)UL  
 
+# Enable debugging mode
+#CDEFS += -DDBG=1
+
 # uncomment and adapt these line if you want different UART library buffer size
 CDEFS += -DUART_RX_BUFFER_SIZE=64
 CDEFS += -DUART_TX_BUFFER_SIZE=64