#include #include #include #include #include "lights.h" #define BATTERY_ADC (N_PWMLEDS + 0) #define BUTTON_ADC (N_PWMLEDS + 1) #define ZERO_ADC (N_PWMLEDS + 2) //#define NUM_ADCS ZERO_ADC #define NUM_ADCS 1 struct { unsigned char read_zero_log : 2; unsigned char read_drop_log : 2; unsigned char read_keep_log : 4; } adc_params[NUM_ADCS] = { { 0, 1, PWMLED_ADC_SHIFT }, // pwmled 1 #if 0 { 0, 1, PWMLED_ADC_SHIFT }, // pwmled 2 { 0, 1, PWMLED_ADC_SHIFT }, // pwmled 3 { 0, 1, AMBIENT_ADC_SHIFT }, // ambient { 0, 1, 0 }, // battery { 0, 1, 0 }, // gain20 { 0, 1, 0 }, // buttons #endif }; volatile static unsigned char current_adc, current_slow_adc; static uint16_t adc_sum, zero_count, drop_count, read_count, n_reads_log; static void setup_mux(unsigned char n) { /* ADC numbering: PWM LEDs first, then others, zero at the end */ switch (n) { case 0: // pwmled 1: 1.1V, ADC3 (PB3), single-ended ADMUX = _BV(REFS1) | _BV(MUX1) | _BV(MUX0); break; case ZERO_ADC: // zero: 1.1V, GND, single-ended ADMUX = _BV(REFS1) | _BV(MUX3) | _BV(MUX2) | _BV(MUX0); break; } } void start_next_adc() { #if 0 if (current_adc == 0) { if (current_slow_adc > N_PWMLEDS) { // read one of the non-PWMLED ADCs current_adc = --current_slow_adc; } else { // no more non-PWMLEDs to do, start with PWMLEDs current_adc = N_PWMLEDS-1; } } else if (current_adc >= N_PWMLEDS) { // one of the non-PWMLED ADCs just finished, skip to PWMLEDs. current_adc = N_PWMLEDS-1; } else { // next PWMLED current_adc--; } #else // single ADC for testing only current_adc = 0; #endif #if 0 log_byte(0x90 + current_adc); // debug ADC switching #endif adc_sum = 0; // we use the last iteration of zero_count to set up the MUX // to its final destination, hence the "1 +" below: if (adc_params[current_adc].read_zero_log) zero_count = 1 + (1 << (adc_params[current_adc].read_zero_log-1)); else zero_count = 1; if (adc_params[current_adc].read_drop_log) drop_count = 1 << (adc_params[current_adc].read_drop_log - 1); else drop_count = 0; read_count = 1 << adc_params[current_adc].read_keep_log; n_reads_log = adc_params[current_adc].read_keep_log; // set up mux, start one-shot conversion if (zero_count > 1) setup_mux(ZERO_ADC); else setup_mux(current_adc); ADCSRA |= _BV(ADSC); } void timer_start_slow_adcs() { if (current_slow_adc > N_PWMLEDS) { // Don't start if in progress log_byte(0x80 + current_slow_adc); } else { current_slow_adc = NUM_ADCS; // TODO: kick the watchdog here } } /* * Single synchronous ADC conversion. * Has to be called with IRQs disabled (or with the ADC IRQ disabled). */ static uint16_t read_adc_sync() { uint16_t rv; ADCSRA |= _BV(ADSC); // start the conversion // wait for the conversion to finish while((ADCSRA & _BV(ADIF)) == 0) ; rv = ADCW; ADCSRA |= _BV(ADIF); // clear the IRQ flag return rv; } void init_adc() { unsigned char i; current_slow_adc = NUM_ADCS; current_adc = 0; power_adc_enable(); ACSR |= _BV(ACD); // but disable the analog comparator ADCSRA = _BV(ADEN) // enable | _BV(ADPS1) | _BV(ADPS0) // CLK/8 = 125 kHz // | _BV(ADPS2) // CLK/16 = 62.5 kHz ; // ADCSRB |= _BV(GSEL); // gain 8 or 32 // Disable digital input on all bits used by ADC DIDR0 = _BV(ADC3D) | _BV(ADC2D); // 1.1V, GND ADMUX = _BV(REFS1) | _BV(MUX3) | _BV(MUX2) | _BV(MUX0); /* Do first conversion and drop the result */ read_adc_sync(); ADCSRA |= _BV(ADIE); // enable IRQ start_next_adc(); } #if 0 void susp_adc() { ADCSRA = 0; DIDR0 = 0; } static void adc1_gain20_adc(uint16_t adcsum) { // running average adc1_gain20_offset += adcsum - (adc1_gain20_offset >> ADC1_GAIN20_OFFSET_SHIFT); } #endif ISR(ADC_vect) { // IRQ handler uint16_t adcval = ADCW; if (zero_count) { if (zero_count > 1) { ADCSRA |= _BV(ADSC); zero_count--; return; } else { setup_mux(current_adc); zero_count = 0; /* fall through */ } } if (drop_count) { ADCSRA |= _BV(ADSC); // drop this one, start the next drop_count--; return; } if (read_count) { ADCSRA |= _BV(ADSC); adc_sum += adcval; read_count--; return; } /* * Now we have performed read_count measurements and have them * in adc_sum. */ switch (current_adc) { case 0: // pwmled_adc(current_adc, adc_sum); pwmled_adc(1, adc_sum); break; } start_next_adc(); }