firmware: buttons + hall probe via ADC

[bike-lights.git] / firmware / adc.c

diff --git a/firmware/adc.c b/firmware/adc.c
index 0ec32af77c0a54db8bbc4b0f8a6ac8476086e15f..b82bc097136d3c70a63defb3290829ecaf3678d3 100644 (file)
--- a/firmware/adc.c
+++ b/firmware/adc.c
@@ -6,8 +6,9 @@
 #define AMBIENT_ADC N_PWMLEDS
 #define BATTERY_ADC (N_PWMLEDS + 1)
 #define ADC1_GAIN20 (N_PWMLEDS + 2)
+#define BUTTON_ADC  (N_PWMLEDS + 2)
 
-#define NUM_ADCS 6
+#define NUM_ADCS 7
 volatile static unsigned char current_adc;
 static uint16_t adc_sum;
 static unsigned char sum_shift;
@@ -42,6 +43,10 @@ static void inline setup_mux(unsigned char n)
        case 5: // gain stage offset: 1.1V, ADC1,1, gain 20
                ADMUX = _BV(REFS1) | _BV(MUX3) | _BV(MUX2) | _BV(MUX0);
                sum_shift = 0; // 1 measurement
+       case 6: // buttons: 1.1V, ADC3, single-ended
+               PORTA |= _BV(PA3); // +5V to the voltage splitter
+               ADMUX = _BV(REFS1) | _BV(MUX1) | _BV(MUX0);
+               sum_shift = 0;
                break;
        }
 
@@ -94,7 +99,7 @@ void init_adc()
        // ADCSRB |= _BV(GSEL); // gain 8 or 32
 
        // Disable digital input on all bits used by ADC
-       DIDR0 = _BV(ADC0D) | _BV(ADC1D) | _BV(ADC2D)
+       DIDR0 = _BV(ADC0D) | _BV(ADC1D) | _BV(ADC2D) | _BV(ADC3D)
                | _BV(ADC4D) | _BV(ADC5D) | _BV(ADC6D);
 
        // 1.1V, ADC1,1, gain 20
@@ -160,6 +165,8 @@ ISR(ADC_vect) { // IRQ handler
                ambient_adc(adc_sum);
        if (current_adc == BATTERY_ADC)
                battery_adc(adcval);
+       if (current_adc == BUTTON_ADC)
+               button_adc(adcval);
        
        start_next_adc();
 }