ADC new APIs and bugfix for 10bit

lib/adc.c

@@ -1,5 +1,6 @@
 #include <avr/io.h>
 #include <stdint.h>
+#include <stdbool.h>
 
 #include "calc.h"
 #include "adc.h"
@@ -8,7 +9,7 @@
 void adc_init(enum ADC_Prescaller presc)
 {
 	ADCSRA |= presc;  // 128 prescaler -> 125 kHz
-	ADMUX  |= _BV(REFS0);  // Voltage reference
+	ADMUX |= _BV(REFS0);  // Voltage reference
 	sbi(ADCSRA, ADEN);  // Enable ADC
 }
 
@@ -24,26 +25,53 @@ void adc_enable(void)
 	sbi(ADCSRA, ADEN);
 }
 
-static void adc_convert(uint8_t channel)
+/** Start a new conversion */
+void adc_start_conversion(uint8_t channel)
 {
 	set_low_nibble(ADMUX, channel);  // Select channel to sample
-	sbi(ADMUX, ADLAR);  // Align result to left
+	cbi(ADMUX, ADLAR);  // Align result to right
 	sbi(ADCSRA, ADSC);  // Start conversion
+}
+
+/** Check if ADC is done converting */
+bool adc_ready(void)
+{
+	return bit_is_low(ADCSRA, ADSC);
+}
+
+/** Read the result of last conversion with 8bit precision */
+uint8_t adc_read_8bit()
+{
+	uint8_t low = ADCL;
+	uint8_t high = ADCH;
+	return low >> 2 | high << 6;
+}
 
-	while (bit_is_high(ADCSRA, ADSC)); // Wait for it...
+/** Read the result of last conversion with 10bit precision */
+uint16_t adc_read_10bit()
+{
+	uint8_t low = ADCL;
+	uint8_t high = ADCH;
+	return ((uint16_t) high << 8) | low;
+}
+
+/** Start ADC conversion and wait for the result */
+static void adc_convert(uint8_t channel)
+{
+	adc_start_conversion(channel);
+	while (!adc_ready()); // Wait for it...
 }
 
 /** Sample analog pin with 8-bit precision */
-uint8_t adc_read_byte(uint8_t channel)
+uint8_t adc_convert_8bit(uint8_t channel)
 {
 	adc_convert(channel);
-	return ADCH;  // The upper 8 bits of ADC result
+	return adc_read_8bit();
 }
 
-
 /** Sample analog pin with 10-bit precision */
-uint16_t adc_read_word(uint8_t channel)
+uint16_t adc_convert_10bit(uint8_t channel)
 {
 	adc_convert(channel);
-	return ADCW;  // The whole ADC word (10 bits)
+	return adc_read_10bit();
 }

lib/adc.h

@@ -25,8 +25,20 @@ void adc_disable(void);
 /** Enable (already initialized) ADC */
 void adc_enable(void);
 
-/** Sample analog pin with 8-bit precision */
-uint8_t adc_read_byte(uint8_t channel);
+/** Start a new conversion */
+void adc_start_conversion(uint8_t channel);
 
-/** Sample analog pin with 10-bit precision */
-uint16_t adc_read_word(uint8_t channel);
+/** Check if ADC is done converting */
+bool adc_ready(void);
+
+/** Read the result of last conversion with 8bit precision */
+uint8_t adc_read_8bit(void);
+
+/** Read the result of last conversion with 10bit precision */
+uint16_t adc_read_10bit(void);
+
+/** Sample analog pin with 8-bit precision. Blocking! */
+uint8_t adc_convert_8bit(uint8_t channel);
+
+/** Sample analog pin with 10-bit precision. Blocking! */
+uint16_t adc_convert_10bit(uint8_t channel);