adc.c: reorder ADC channels

- those which need to be measured more frequently, put at the beginning.

diff --git a/firmware/adc.c b/firmware/adc.c
index ef714777011f1af24d171bb44cdd0d6461ac6b0e..c6b113d4932cb538768fb8f94674d53af34a2483 100644 (file)
--- a/firmware/adc.c
+++ b/firmware/adc.c
@@ -3,11 +3,12 @@
 
 #include "lights.h"
 
-#define AMBIENT_ADC N_PWMLEDS
-#define BATTERY_ADC (N_PWMLEDS + 1)
-#define ADC1_GAIN20 (N_PWMLEDS + 2)
-#define BUTTON_ADC  (N_PWMLEDS + 3)
-#define ZERO_ADC    (N_PWMLEDS + 4)
+// pwmleds are measured continuously (when active)
+#define AMBIENT_ADC N_PWMLEDS          // measured every jiffy (16 Hz)
+#define BUTTON_ADC  (N_PWMLEDS + 1)    // measured every jiffy (16 Hz)
+#define BATTERY_ADC (N_PWMLEDS + 2)    // once per second
+#define ADC1_GAIN20 (N_PWMLEDS + 3)    // once per second
+#define ZERO_ADC    (N_PWMLEDS + 4)    // must be last
 
 #define NUM_ADCS       ZERO_ADC
 
@@ -20,9 +21,9 @@ struct {
        { 0, 1, PWMLED_ADC_SHIFT },     // pwmled 2
        { 0, 1, PWMLED_ADC_SHIFT },     // pwmled 3
        { 0, 1, AMBIENT_ADC_SHIFT },    // ambient
+       { 0, 1, 0 },                    // buttons
        { 0, 1, 0 },                    // battery
        { 0, 1, 0 },                    // gain20
-       { 0, 1, 0 },                    // buttons
 };
 
 volatile static unsigned char current_adc, current_slow_adc;
@@ -47,16 +48,16 @@ static void setup_mux(unsigned char n)
        case AMBIENT_ADC: // ambient light: 1.1V, ADC5 (PA6), single-ended
                ADMUX = _BV(REFS1) | _BV(MUX2) | _BV(MUX0);
                break;
+       case BUTTON_ADC: // buttons: 1.1V, ADC3, single-ended
+               PORTA |= _BV(PA3); // +5V to the voltage splitter
+               ADMUX = _BV(REFS1) | _BV(MUX1) | _BV(MUX0);
+               break;
        case BATTERY_ADC: // batt voltage: 1.1V, ADC6 (PA7), single-ended
                ADMUX = _BV(REFS1) | _BV(MUX2) | _BV(MUX1);
                break;
        case ADC1_GAIN20: // gain stage offset: 1.1V, ADC1,1, gain 20
                ADMUX = _BV(REFS1) | _BV(MUX3) | _BV(MUX2) | _BV(MUX0);
                break;
-       case BUTTON_ADC: // buttons: 1.1V, ADC3, single-ended
-               PORTA |= _BV(PA3); // +5V to the voltage splitter
-               ADMUX = _BV(REFS1) | _BV(MUX1) | _BV(MUX0);
-               break;
        case ZERO_ADC: // zero: 1.1V, ADC1 (PA1), single-ended
                ADMUX = _BV(REFS1) | _BV(MUX0);
                break;
@@ -240,12 +241,12 @@ ISR(ADC_vect) { // IRQ handler
        case AMBIENT_ADC:
                ambient_adc(adc_sum);
                break;
-       case BATTERY_ADC:
-               battery_adc(adc_sum);
-               break;
        case BUTTON_ADC:
                button_adc(adc_sum);
                break;
+       case BATTERY_ADC:
+               battery_adc(adc_sum);
+               break;
        case ADC1_GAIN20:
                adc1_gain20_adc(adcval);
                break;