adc.c: freewheeling measurements of ADC3 only (4b42bb17) · Commits · Jan Kasprzak / tinyboard

projects/step-up/adc.c

+25 −70

Original line number	Original line	Diff line number	Diff line
	#include <avr/io.h>		#include <avr/io.h>
	#include <avr/interrupt.h>		#include <avr/interrupt.h>
			#include <avr/sleep.h>

	#include "lights.h"		#include "lights.h"

	#define AMBIENT_ADC N_PWMLEDS		#define BATTERY_ADC (N_PWMLEDS + 0)
	#define BATTERY_ADC (N_PWMLEDS + 1)		#define BUTTON_ADC (N_PWMLEDS + 1)
	#define ADC1_GAIN20 (N_PWMLEDS + 2)		#define ZERO_ADC (N_PWMLEDS + 2)
	#define BUTTON_ADC (N_PWMLEDS + 3)
	#define ZERO_ADC (N_PWMLEDS + 4)

	#define NUM_ADCS ZERO_ADC		//#define NUM_ADCS ZERO_ADC
			#define NUM_ADCS 1

	struct {		struct {
	unsigned char read_zero_log : 2;		unsigned char read_zero_log : 2;
	@@ -17,54 +17,36 @@ struct {
	unsigned char read_keep_log : 4;		unsigned char read_keep_log : 4;
	} adc_params[NUM_ADCS] = {		} adc_params[NUM_ADCS] = {
	{ 0, 1, PWMLED_ADC_SHIFT }, // pwmled 1		{ 0, 1, PWMLED_ADC_SHIFT }, // pwmled 1
			#if 0
	{ 0, 1, PWMLED_ADC_SHIFT }, // pwmled 2		{ 0, 1, PWMLED_ADC_SHIFT }, // pwmled 2
	{ 0, 1, PWMLED_ADC_SHIFT }, // pwmled 3		{ 0, 1, PWMLED_ADC_SHIFT }, // pwmled 3
	{ 0, 1, AMBIENT_ADC_SHIFT }, // ambient		{ 0, 1, AMBIENT_ADC_SHIFT }, // ambient
	{ 0, 1, 0 }, // battery		{ 0, 1, 0 }, // battery
	{ 0, 1, 0 }, // gain20		{ 0, 1, 0 }, // gain20
	{ 0, 1, 0 }, // buttons		{ 0, 1, 0 }, // buttons
			#endif
	};		};

	volatile static unsigned char current_adc, current_slow_adc;		volatile static unsigned char current_adc, current_slow_adc;
	static uint16_t adc_sum, zero_count, drop_count, read_count, n_reads_log;		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 void setup_mux(unsigned char n)		static void setup_mux(unsigned char n)
	{		{
	/* ADC numbering: PWM LEDs first, then others, zero at the end */		/* ADC numbering: PWM LEDs first, then others, zero at the end */
	switch (n) {		switch (n) {
	case 0: // pwmled 1: 1.1V, ADC0,1 (PA0,1), gain 20		case 0: // pwmled 1: 1.1V, ADC3 (PB3), single-ended
	ADMUX = _BV(REFS1) \| _BV(MUX3) \| _BV(MUX1) \| _BV(MUX0);
	break;
	case 1: // pwmled 2: 1.1V, ADC2,1 (PA2,1), gain 20
	ADMUX = _BV(REFS1) \| _BV(MUX3) \| _BV(MUX2) \| _BV(MUX1);
	break;
	case 2: // pwmled 3: 1.1V, ADC4 (PA5), single-ended
	ADMUX = _BV(REFS1) \| _BV(MUX2);
	break;
	case AMBIENT_ADC: // ambient light: 1.1V, ADC5 (PA6), single-ended
	ADMUX = _BV(REFS1) \| _BV(MUX2) \| _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);		ADMUX = _BV(REFS1) \| _BV(MUX1) \| _BV(MUX0);
	break;		break;
	case ZERO_ADC: // zero: 1.1V, ADC1 (PA1), single-ended		case ZERO_ADC: // zero: 1.1V, GND, single-ended
	ADMUX = _BV(REFS1) \| _BV(MUX0);		ADMUX = _BV(REFS1) \| _BV(MUX3) \| _BV(MUX2) \| _BV(MUX0);
	break;		break;
	}		}
	}		}

	static void start_next_adc()		void start_next_adc()
	{		{
			#if 0
	if (current_adc == 0) {		if (current_adc == 0) {
	if (current_slow_adc > N_PWMLEDS) {		if (current_slow_adc > N_PWMLEDS) {
	// read one of the non-PWMLED ADCs		// read one of the non-PWMLED ADCs
	@@ -80,6 +62,10 @@ static void start_next_adc()
	// next PWMLED		// next PWMLED
	current_adc--;		current_adc--;
	}		}
			#else
			// single ADC for testing only
			current_adc = 0;
			#endif

	#if 0		#if 0
	log_byte(0x90 + current_adc); // debug ADC switching		log_byte(0x90 + current_adc); // debug ADC switching
	@@ -153,27 +139,20 @@ void init_adc()
	// ADCSRB \|= _BV(GSEL); // gain 8 or 32		// ADCSRB \|= _BV(GSEL); // gain 8 or 32

	// Disable digital input on all bits used by ADC		// Disable digital input on all bits used by ADC
	DIDR0 = _BV(ADC0D) \| _BV(ADC1D) \| _BV(ADC2D) \| _BV(ADC3D)		DIDR0 = _BV(ADC3D) \| _BV(ADC2D);
	\| _BV(ADC4D) \| _BV(ADC5D) \| _BV(ADC6D);

	// 1.1V, ADC1,1, gain 20		// 1.1V, GND
	ADMUX = _BV(REFS1) \| _BV(MUX3) \| _BV(MUX2) \| _BV(MUX0);		ADMUX = _BV(REFS1) \| _BV(MUX3) \| _BV(MUX2) \| _BV(MUX0);

	/* Do first conversion and drop the result */		/* Do first conversion and drop the result */
	read_adc_sync();		read_adc_sync();

	adc1_gain20_offset = 0;

	for (i = 0; i < (1 << ADC1_GAIN20_OFFSET_SHIFT); i++) {
	adc1_gain20_offset += read_adc_sync()
	- (adc1_gain20_offset >> ADC1_GAIN20_OFFSET_SHIFT);
	}

	ADCSRA \|= _BV(ADIE); // enable IRQ		ADCSRA \|= _BV(ADIE); // enable IRQ

	start_next_adc();		start_next_adc();
	}		}

			#if 0
	void susp_adc()		void susp_adc()
	{		{
	ADCSRA = 0;		ADCSRA = 0;
	@@ -186,6 +165,7 @@ static void adc1_gain20_adc(uint16_t adcsum)
	adc1_gain20_offset += adcsum		adc1_gain20_offset += adcsum
	- (adc1_gain20_offset >> ADC1_GAIN20_OFFSET_SHIFT);		- (adc1_gain20_offset >> ADC1_GAIN20_OFFSET_SHIFT);
	}		}
			#endif

	ISR(ADC_vect) { // IRQ handler		ISR(ADC_vect) { // IRQ handler
	uint16_t adcval = ADCW;		uint16_t adcval = ADCW;
	@@ -219,38 +199,13 @@ ISR(ADC_vect) { // IRQ handler
	* Now we have performed read_count measurements and have them		* Now we have performed read_count measurements and have them
	* in adc_sum.		* in adc_sum.
	*/		*/

	// For inputs with gain, subtract the measured gain stage offset
	if (current_adc < 2) {
	uint16_t offset = adc1_gain20_offset
	>> (ADC1_GAIN20_OFFSET_SHIFT - n_reads_log);

	if (adc_sum > offset)
	adc_sum -= offset;
	else
	adc_sum = 0;
	}

	switch (current_adc) {		switch (current_adc) {
	case 0:		case 0:
	case 1:		// pwmled_adc(current_adc, adc_sum);
	case 2:		log_word(0x9000+adc_sum);
	pwmled_adc(current_adc, adc_sum);		return;
	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;		break;
	}		}

	start_next_adc();		start_next_adc();
	}		}