2 #include <avr/interrupt.h>
6 static unsigned char adc_mux[] = { // pwmleds should be first
7 // 0: pwmled 0: 1.1V, ADC3 (PA4), single-ended
8 _BV(REFS1) | _BV(MUX1) | _BV(MUX0),
9 // 1: pwmled 1: 1.1V, ADC0,1 (PA0,1), gain 1 or 8
10 _BV(REFS1) | _BV(MUX3) | _BV(MUX2),
11 // 2: pwmled 2: 1.1V, ADC2,1 (PA2,1), gain 1 or 8
12 _BV(REFS1) | _BV(MUX3) | _BV(MUX2) | _BV(MUX1) | _BV(MUX0),
13 // 3: ambient light: 1.1V, ADC4 (PA5), single-ended
14 _BV(REFS1) | _BV(MUX2),
15 // 4: batt voltage: 1.1V, ADC5 (PA6), single-ended
16 _BV(REFS1) | _BV(MUX2) | _BV(MUX0),
19 #define LAST_ADC (sizeof(adc_mux)/sizeof(char))
20 volatile static unsigned char current_adc = LAST_ADC;
22 static void start_next_adc()
24 while (current_adc > 0) {
27 // test if current_adc should be measured
28 if (current_adc < N_PWMLEDS && pwmled_is_on(current_adc))
30 // TODO ambient light, battery sense, etc.
33 // all ADCs have been handled
34 current_adc = LAST_ADC;
37 // ADCSRB |= _BV(GSEL); // gain 8 or 32
38 ADMUX = adc_mux[current_adc]; // set up mux, start one-shot conversion
44 ADCSRA = _BV(ADEN) // enable
45 | _BV(ADPS1) | _BV(ADPS0) // CLK/8 = 125 kHz
46 // | _BV(ADPS2) // CLK/16 = 62.5 kHz
48 ADCSRB |= _BV(GSEL); // gain 8 or 32
50 // Disable digital input on all bits used by ADC
51 DIDR0 = _BV(ADC0D) | _BV(ADC1D) | _BV(ADC2D) | _BV(ADC3D)
52 | _BV(ADC4D) | _BV(ADC5D);
56 /* Do first conversion and drop the result */
57 while ((ADCSRA & _BV(ADIF)) == 0)
59 ADCSRA |= _BV(ADIF); // clear the IRQ flag
61 ADCSRA |= _BV(ADIE); // enable IRQ
64 ISR(ADC_vect) { // IRQ handler
65 uint16_t adcval = ADCW;
67 if (current_adc < N_PWMLEDS)
68 pwmled_adc(current_adc, adcval);
69 // TODO ambient light, battery sense, etc.
74 void timer_start_adcs()
76 if (current_adc == LAST_ADC) // Don't start if in progress