#include <avr/io.h>
#include <avr/interrupt.h>
-#include <util/atomic.h>
#include "lights.h"
#define AMBIENT_ADC N_PWMLEDS
#define BATTERY_ADC (N_PWMLEDS + 1)
#define ADC1_GAIN20 (N_PWMLEDS + 2)
-
-#define NUM_ADCS 6
-volatile static unsigned char current_adc;
-static uint16_t adc_sum;
-static unsigned char sum_shift;
-static unsigned char adc_vals;
+#define BUTTON_ADC (N_PWMLEDS + 3)
+#define ZERO_ADC (N_PWMLEDS + 4)
+
+#define NUM_ADCS ZERO_ADC
+
+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
+ { 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
+};
+
+volatile static unsigned char current_adc, current_slow_adc;
+static uint16_t adc_sum, zero_count, drop_count, read_count, n_reads_log;
#define ADC1_GAIN20_OFFSET_SHIFT 6
static uint16_t adc1_gain20_offset;
-static unsigned char handler_running;
-static void inline setup_mux(unsigned char n)
+
+static void setup_mux(unsigned char n)
{
- /* ADC numbering: PWM LEDs first, then ambient light sensor, battery sensor */
+ /* ADC numbering: PWM LEDs first, then others, zero at the end */
switch (n) {
case 0: // pwmled 1: 1.1V, ADC0,1 (PA0,1), gain 20
ADMUX = _BV(REFS1) | _BV(MUX3) | _BV(MUX1) | _BV(MUX0);
- sum_shift = PWMLED_ADC_SHIFT;
break;
case 1: // pwmled 2: 1.1V, ADC2,1 (PA2,1), gain 20
ADMUX = _BV(REFS1) | _BV(MUX3) | _BV(MUX2) | _BV(MUX1);
- sum_shift = PWMLED_ADC_SHIFT;
break;
case 2: // pwmled 3: 1.1V, ADC4 (PA5), single-ended
ADMUX = _BV(REFS1) | _BV(MUX2);
- sum_shift = PWMLED_ADC_SHIFT;
break;
- case 3: // ambient light: 1.1V, ADC5 (PA6), single-ended
+ case AMBIENT_ADC: // ambient light: 1.1V, ADC5 (PA6), single-ended
ADMUX = _BV(REFS1) | _BV(MUX2) | _BV(MUX0);
- sum_shift = 3; // 3 measurements
break;
- case 4: // batt voltage: 1.1V, ADC6 (PA7), single-ended
+ case BATTERY_ADC: // batt voltage: 1.1V, ADC6 (PA7), single-ended
ADMUX = _BV(REFS1) | _BV(MUX2) | _BV(MUX1);
- sum_shift = 0; // 1 measurement
break;
- case 5: // gain stage offset: 1.1V, ADC1,1, gain 20
+ case ADC1_GAIN20: // gain stage offset: 1.1V, ADC1,1, gain 20
ADMUX = _BV(REFS1) | _BV(MUX3) | _BV(MUX2) | _BV(MUX0);
- sum_shift = 0; // 1 measurement
+ 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;
}
-
- adc_sum = 0;
- adc_vals = 1 << sum_shift;
}
static void start_next_adc()
{
- if (current_adc > 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--;
+ }
+
+#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
- // TODO: kick the watchdog here.
- current_adc = NUM_ADCS-1;
+ 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
- setup_mux(current_adc);
+ 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).
void init_adc()
{
unsigned char i;
- current_adc = NUM_ADCS;
- handler_running = 0;
+ current_slow_adc = NUM_ADCS;
+ current_adc = 0;
ADCSRA = _BV(ADEN) // enable
| _BV(ADPS1) | _BV(ADPS0) // CLK/8 = 125 kHz
// 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
DIDR0 = 0;
}
+static void adc1_gain20_adc(uint16_t adcsum)
+{
+ // running average
+ adc1_gain20_offset += adcsum
+ - (adc1_gain20_offset >> ADC1_GAIN20_OFFSET_SHIFT);
+}
+
ISR(ADC_vect) { // IRQ handler
uint16_t adcval = ADCW;
- if (adc_vals)
- // start the next conversion immediately
- ADCSRA |= _BV(ADSC);
-
- if (adc_vals < (1 << sum_shift))
- // drop the first conversion, use all others
- adc_sum += adcval;
+ if (zero_count) {
+ if (zero_count > 1) {
+ ADCSRA |= _BV(ADSC);
+ zero_count--;
+ return;
+ } else {
+ setup_mux(current_adc);
+ zero_count = 0;
+ /* fall through */
+ }
+ }
- if (adc_vals) {
- adc_vals--;
+ if (drop_count) {
+ ADCSRA |= _BV(ADSC); // drop this one, start the next
+ drop_count--;
return;
}
- // Now handle the (1 << sum_shift) measurements
+ if (read_count) {
+ ADCSRA |= _BV(ADSC);
+ adc_sum += adcval;
+ read_count--;
+ return;
+ }
- adcval = adc_sum >> sum_shift;
+ /*
+ * Now we have performed read_count measurements and have them
+ * in adc_sum.
+ */
- if (current_adc == ADC1_GAIN20) {
- // running average
- adc1_gain20_offset += adcval
- - (adc1_gain20_offset >> ADC1_GAIN20_OFFSET_SHIFT);
- } else if (current_adc == 0 || current_adc == 1) {
+ // For inputs with gain, subtract the measured gain stage offset
+ if (current_adc < 2) {
uint16_t offset = adc1_gain20_offset
- >> (ADC1_GAIN20_OFFSET_SHIFT - sum_shift);
+ >> (ADC1_GAIN20_OFFSET_SHIFT - n_reads_log);
+
if (adc_sum > offset)
adc_sum -= offset;
else
adc_sum = 0;
}
- if (handler_running & (1 << current_adc)) {
- log_byte(0xB0 + current_adc);
-
- // drop the result, what else to do?
-
- start_next_adc();
- } else {
- unsigned char current_adc_copy = current_adc;
- uint16_t adc_sum_copy = adc_sum;
-
- start_next_adc();
-
- handler_running |= (1 << current_adc_copy);
- NONATOMIC_BLOCK(NONATOMIC_FORCEOFF) {
- if (current_adc_copy < N_PWMLEDS)
- pwmled_adc(current_adc_copy, adc_sum_copy);
- if (current_adc_copy == AMBIENT_ADC)
- ambient_adc(adc_sum_copy);
- if (current_adc_copy == BATTERY_ADC)
- battery_adc(adc_sum_copy);
- }
- handler_running &= ~(1 << current_adc_copy);
+ switch (current_adc) {
+ case 0:
+ case 1:
+ case 2:
+ pwmled_adc(current_adc, adc_sum);
+ break;
+ 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 ADC1_GAIN20:
+ adc1_gain20_adc(adcval);
+ break;
}
+
+ start_next_adc();
}
https://www.fi.muni.cz/~kas/git / bike-lights.git / blobdiff