voltage.c File Reference

#include <inttypes.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include "voltage.h"
#include "util.h"

Include dependency graph for voltage.c:

Functions
void	pump_init ()
	Setup PWM output for the boost converter.
void	pump_nomoar ()
	Terminate boost converter operation.
void	pump_faster (int8_t dfreq)
void	voltage_adjust (uint8_t flag)
void	voltage_adjust_tick ()
void	adc_init ()
	Init ADC converter and ADC interrupt.
	ISR (ADC_vect)
Variables
volatile uint16_t	voltage
	voltage (magic units)
volatile uint16_t	voltage_setpoint = 400
	voltage setpoints (magic units)
uint8_t	on_duty
	values 1..4, gets multiplied by 4
uint16_t	time
	current display value

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Function Documentation

void adc_init

(

)

Init ADC converter and ADC interrupt.

                {
    voltage = 0;
    
    // PORTA.7 is the feedback input, AREF = AREF pin
    ADMUX = 7;  
    DDRA &= ~_BV(7);

    // ADC enable, autotrigger, interrupt enable, prescaler = 111 (divide by 32)
    ADCSRA = BV6(ADEN, ADATE, ADIE, ADPS2, ADPS1, ADPS0); 
    //ADCSRA = BV5(ADEN, ADIE, ADPS2, ADPS1, ADPS0); 

    ADCSRA |= _BV(ADSC); 
}

ISR

(

ADC_vect

)

              {
    voltage = (voltage + ADC) / 2;
    if (voltage < voltage_setpoint) {
        OCR1A = 37;
    } else {
        OCR1A = 0;
    }
}

void pump_faster

(

int8_t

dfreq

)

                               {
    ICR1 += dfreq;
}

void pump_init

(

)

Setup PWM output for the boost converter.

                 {
    // set fast pwm mode
    // COM1A1:0 = 10, clear oc1a on compare match, set at top
    // COM1B1:0 = 00, normal port operation
    // no FOC
    // WGM11:10 (WGM = Fast PWM, TOP=ICR1: 1110) = 11
    TCCR1A = BV2(COM1A1, WGM11);
    TCCR1B = BV2(WGM13,WGM12);
    
    OCR1A = 37; 
    ICR1 = 50;
    
    TCCR1B |= _BV(CS10); // clk/1 = 8MHz
    
    DDRD |= BV2(5,4);
}

void pump_nomoar

(

)

Terminate boost converter operation.

                   {
    ADCSRA = 0;
    ADCSRA |= _BV(ADIF); 

    ICR1 = 255;
    OCR1A = 0;
    OCR1B = OCR1A;
}

void voltage_adjust

(

uint8_t

flag

)

[inline]

Adjust output voltage for specific display contents and duty cycle. flag = 0 initiates adjustment. Logic is magic.

                                         {
    switch (flag) {
    case 0:
        if (on_duty == 4) {
            if (((time & 0x00f0)>>4) == 2) {
                voltage_setpoint = 410;
                cli();
                voltage_delayed = 380;
                voltage_delay_count = 64;
                sei();
            } else {
                voltage_setpoint = 380;
            }
        } else {
            voltage_setpoint = 400;
        }
        break;
    case 1:
        voltage_setpoint = voltage_delayed;
        break;
    }
}

void voltage_adjust_tick

(

)

Must be called every tick from the main timer interrupt routine. After voltage delay is expired, sets voltage setpoint to postponed value.

                           {
    if (voltage_delay_count != 0) {
        voltage_delay_count--;
        if (voltage_delay_count == 0) {
            voltage_adjust(1);
        }
    }
}

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Variable Documentation

uint8_t on_duty

values 1..4, gets multiplied by 4

uint16_t time

current display value

volatile uint16_t voltage

voltage (magic units)

volatile uint16_t voltage_setpoint = 400

voltage setpoints (magic units)