dual pwm first try

/* STAR_off_time version 1.2
 *
 * Changelog
 *
 * 1.0 Initial version
 * 1.1 Bug fix
 * 1.2 Added support for dual PWM outputs and selection of PWM mode per output level
 * 1.3 Added ability to have turbo ramp down gradually instead of step down
 *
 */

/*
 * NANJG 105C Diagram
 *           ---
 *         -|   |- VCC
 *  Star 4 -|   |- Voltage ADC
 *  Star 3 -|   |- PWM
 *     GND -|   |- Star 2
 *           ---
 *
 * FUSES
 *      I use these fuse settings
 *      Low:  0x75  (4.8MHz CPU without 8x divider, 9.4kHz phase-correct PWM or 18.75kHz fast-PWM)
 *      High: 0xff
 *
 *      For more details on these settings, visit http://github.com/JCapSolutions/blf-firmware/wiki/PWM-Frequency
 *
 * STARS
 *      Star 2 = Moon if connected and alternate PWM output not used
 *      Star 3 = H-L if connected, L-H if not
 *      Star 4 = Capacitor for off-time
 *
 * VOLTAGE
 *      Resistor values for voltage divider (reference BLF-VLD README for more info)
 *      Reference voltage can be anywhere from 1.0 to 1.2, so this cannot be all that accurate
 *
 *           VCC
 *            |
 *           Vd (~.25 v drop from protection diode)
 *            |
 *          1912 (R1 19,100 ohms)
 *            |
 *            |---- PB2 from MCU
 *            |
 *          4701 (R2 4,700 ohms)
 *            |
 *           GND
 *
 *      ADC = ((V_bat - V_diode) * R2   * 255) / ((R1    + R2  ) * V_ref)
 *      125 = ((3.0   - .25    ) * 4700 * 255) / ((19100 + 4700) * 1.1  )
 *      121 = ((2.9   - .25    ) * 4700 * 255) / ((19100 + 4700) * 1.1  )
 *
 *      Well 125 and 121 were too close, so it shut off right after lowering to low mode, so I went with
 *      130 and 120
 *
 *      To find out what value to use, plug in the target voltage (V) to this equation
 *          value = (V * 4700 * 255) / (23800 * 1.1)
 *
 */
#define F_CPU 4800000UL

/*
 * =========================================================================
 * Settings to modify per driver
 */

#define VOLTAGE_MON         // Comment out to disable

#define MEMORY              // Comment out to disable

//#define TICKS_250MS       // If enabled, ticks are every 250 ms. If disabled, ticks are every 500 ms
                            // Affects turbo timeout/rampdown timing

#define MODE_MOON           3   // Can comment out to remove mode, but should be set through soldering stars
#define MODE_LOW            14  // Can comment out to remove mode
#define MODE_MED            39  // Can comment out to remove mode
//#define MODE_HIGH         255 // Can comment out to remove mode
#define MODE_TURBO          255 // Can comment out to remove mode
#define MODE_TURBO_LOW      150 // Level turbo ramps down to if turbo enabled
#define TURBO_TIMEOUT       240 // How many WTD ticks before before dropping down.  If ticks set for 500 ms, then 240 x .5 = 120 seconds.  Max value of 255 unless you change "ticks"
                                // variable to uint8_t
#define TURBO_RAMP_DOWN           // By default we will start to gradually ramp down, once TURBO_TIMEOUT ticks are reached, 1 PWM_LVL each tick until reaching MODE_TURBO_LOW PWM_LVL
                                // If commented out, we will step down to MODE_TURBO_LOW once TURBO_TIMEOUT ticks are reached

#define FAST_PWM_START      8 // Above what output level should we switch from phase correct to fast-PWM?
#define DUAL_PWM_START        8 // Above what output level should we switch from the alternate PWM output to both PWM outputs?  Comment out to disable alternate PWM output

#define ADC_LOW             130 // When do we start ramping
#define ADC_CRIT            120 // When do we shut the light off

#define CAP_THRESHOLD       130  // Value between 1 and 255 corresponding with cap voltage (0 - 1.1v) where we consider it a short press to move to the next mode
                                 // Not sure the lowest you can go before getting bad readings, but with a value of 70 and a 1uF cap, it seemed to switch sometimes
                                 // even when waiting 10 seconds between presses.

/*
 * =========================================================================
 */

//#include <avr/pgmspace.h>
#include <avr/io.h>
#include <util/delay.h>
#include <avr/interrupt.h>
#include <avr/wdt.h>
#include <avr/eeprom.h>
#include <avr/sleep.h>
//#include <avr/power.h>

#define STAR2_PIN   PB0
#define STAR3_PIN   PB4
#define CAP_PIN     PB3
#define CAP_CHANNEL 0x03    // MUX 03 corresponds with PB3 (Star 4)
#define CAP_DIDR    ADC3D   // Digital input disable bit corresponding with PB3
#define PWM_PIN     PB1
#define VOLTAGE_PIN PB2
#define ADC_CHANNEL 0x01    // MUX 01 corresponds with PB2
#define ADC_DIDR    ADC1D   // Digital input disable bit corresponding with PB2
#define ADC_PRSCL   0x06    // clk/64

#define PWM_LVL     OCR0B   // OCR0B is the output compare register for PB1
#define ALT_PWM_LVL OCR0A   // OCR0A is the output compare register for PB0

/*
 * global variables
 */

// Mode storage
uint8_t eepos = 0;
uint8_t eep[32];
uint8_t memory = 0;

// Modes (gets set when the light starts up based on stars)
static uint8_t modes[10];  // Don't need 10, but keeping it high enough to handle all
volatile uint8_t mode_idx = 0;
int     mode_dir = 0; // 1 or -1. Determined when checking stars. Do we increase or decrease the idx when moving up to a higher mode.
uint8_t mode_cnt = 0;

uint8_t lowbatt_cnt = 0;

void store_mode_idx(uint8_t lvl) {  //central method for writing (with wear leveling)
    uint8_t oldpos=eepos;
    eepos=(eepos+1)&31;  //wear leveling, use next cell
    // Write the current mode
    EEARL=eepos;  EEDR=lvl; EECR=32+4; EECR=32+4+2;  //WRITE  //32:write only (no erase)  4:enable  2:go
    while(EECR & 2); //wait for completion
    // Erase the last mode
    EEARL=oldpos;           EECR=16+4; EECR=16+4+2;  //ERASE  //16:erase only (no write)  4:enable  2:go
}
inline void read_mode_idx() {
    eeprom_read_block(&eep, 0, 32);
    while((eep[eepos] == 0xff) && (eepos < 32)) eepos++;
    if (eepos < 32) mode_idx = eep[eepos];//&0x10; What the?
    else eepos=0;
}

inline void next_mode() {
    if (mode_idx == 0 && mode_dir == -1) {
        // Wrap around
        mode_idx = mode_cnt - 1;
    } else {
        mode_idx += mode_dir;
        if (mode_idx > (mode_cnt - 1)) {
            // Wrap around
            mode_idx = 0;
        }
    }
}

inline void check_stars() {
    // Load up the modes based on stars
    // Always load up the modes array in order of lowest to highest mode
    // 0 being low for soldered, 1 for pulled-up for not soldered
    // Moon
#ifdef MODE_MOON
#ifndef DUAL_PWM_START
    if ((PINB & (1 << STAR2_PIN)) == 0) {
#endif
        modes[mode_cnt++] = MODE_MOON;
#ifndef DUAL_PWM_START
    }
#endif
#endif
#ifdef MODE_LOW
    modes[mode_cnt++] = MODE_LOW;
#endif
#ifdef MODE_MED
    modes[mode_cnt++] = MODE_MED;
#endif
#ifdef MODE_HIGH
    modes[mode_cnt++] = MODE_HIGH;
#endif
#ifdef MODE_TURBO
    modes[mode_cnt++] = MODE_TURBO;
#endif
    if ((PINB & (1 << STAR3_PIN)) == 0) {
        // High to Low
        mode_dir = -1;
    } else {
        mode_dir = 1;
    }
}

inline void WDT_on() {
    // Setup watchdog timer to only interrupt, not reset
    cli();                          // Disable interrupts
    wdt_reset();                    // Reset the WDT
    WDTCR |= (1<<WDCE) | (1<<WDE);  // Start timed sequence
    #ifdef TICKS_250MS
    WDTCR = (1<<WDTIE) | (1<<WDP2); // Enable interrupt every 250ms
    #else
    WDTCR = (1<<WDTIE) | (1<<WDP2) | (1<<WDP0); // Enable interrupt every 500ms
    #endif
    sei();                          // Enable interrupts
}

inline void WDT_off()
{
    cli();                          // Disable interrupts
    wdt_reset();                    // Reset the WDT
    MCUSR &= ~(1<<WDRF);            // Clear Watchdog reset flag
    WDTCR |= (1<<WDCE) | (1<<WDE);  // Start timed sequence
    WDTCR = 0x00;                   // Disable WDT
    sei();                          // Enable interrupts
}

inline void ADC_on() {
    DIDR0 |= (1 << ADC_DIDR);                           // disable digital input on ADC pin to reduce power consumption
    ADMUX  = (1 << REFS0) | (1 << ADLAR) | ADC_CHANNEL; // 1.1v reference, left-adjust, ADC1/PB2
    ADCSRA = (1 << ADEN ) | (1 << ADSC ) | ADC_PRSCL;   // enable, start, prescale
}

inline void ADC_off() {
    ADCSRA &= ~(1<<7); //ADC off
}

void set_output(uint8_t pwm_lvl) {
    #ifdef DUAL_PWM_START
    if (pwm_lvl > DUAL_PWM_START) {
        // Using the normal output along with the alternate
        PWM_LVL = pwm_lvl;
    } else {
        PWM_LVL = 0;
    }
    #else
    PWM_LVL = pwm_lvl;
    #endif
    // Always set alternate PWM value even if not compiled for dual output as we will use this value
    // throughout the code when trying to see what the current output level is.  Setting this wont affect
    // the output when alternate output is disabled.
    ALT_PWM_LVL = pwm_lvl;
}

#ifdef VOLTAGE_MON
uint8_t low_voltage(uint8_t voltage_val) {
    // Start conversion
    ADCSRA |= (1 << ADSC);
    // Wait for completion
    while (ADCSRA & (1 << ADSC));
    // See if voltage is lower than what we were looking for
    if (ADCH < voltage_val) {
        // See if it's been low for a while
        if (++lowbatt_cnt > 8) {
            lowbatt_cnt = 0;
            return 1;
        }
    } else {
        lowbatt_cnt = 0;
    }
    return 0;
}
#endif

ISR(WDT_vect) {
    static uint8_t ticks = 0;
    if (ticks < 255) ticks++;
    // If you want more than 255 for longer turbo timeouts
    //static uint16_t ticks = 0;
    //if (ticks < 60000) ticks++;

#ifdef MODE_TURBO
    //if (ticks == TURBO_TIMEOUT && modes[mode_idx] == MODE_TURBO) { // Doesn't make any sense why this doesn't work
    if (ticks >= TURBO_TIMEOUT && mode_idx == (mode_cnt - 1) && PWM_LVL > MODE_TURBO_LOW) {
        #ifdef TURBO_RAMP_DOWN
        set_output(PWM_LVL - 1);
        #else
        // Turbo mode is always at end
        set_output(MODE_TURBO_LOW);
        if (MODE_TURBO_LOW <= modes[mode_idx-1]) {
            // Dropped at or below the previous mode, so set it to the stored mode
            // Kept this as it was the same functionality as before.  For the TURBO_RAMP_DOWN feature
            // it doesn't do this logic because I don't know what makes the most sense
            store_mode_idx(--mode_idx);
        }
        #endif
    }
#endif

}

int main(void)
{
    // All ports default to input, but turn pull-up resistors on for the stars (not the ADC input!  Made that mistake already)
    #ifdef DUAL_PWM_START
    PORTB = (1 << STAR3_PIN);
    #else
    PORTB = (1 << STAR2_PIN) | (1 << STAR3_PIN);
    #endif

    // Determine what mode we should fire up
    // Read the last mode that was saved
    read_mode_idx();

    check_stars(); // Moving down here as it might take a bit for the pull-up to turn on?

    // Start up ADC for capacitor pin
    DIDR0 |= (1 << CAP_DIDR);                           // disable digital input on ADC pin to reduce power consumption
    ADMUX  = (1 << REFS0) | (1 << ADLAR) | CAP_CHANNEL; // 1.1v reference, left-adjust, ADC3/PB3
    ADCSRA = (1 << ADEN ) | (1 << ADSC ) | ADC_PRSCL;   // enable, start, prescale

    // Wait for completion
    while (ADCSRA & (1 << ADSC));
    // Start again as datasheet says first result is unreliable
    ADCSRA |= (1 << ADSC);
    // Wait for completion
    while (ADCSRA & (1 << ADSC));
    if (ADCH > CAP_THRESHOLD) {
        // Indicates they did a short press, go to the next mode
        next_mode(); // Will handle wrap arounds
        store_mode_idx(mode_idx);
    } else {
        // Didn't have a short press, keep the same mode
    #ifndef MEMORY
        // Reset to the first mode
        mode_idx = ((mode_dir == 1) ? 0 : (mode_cnt - 1));
        store_mode_idx(mode_idx);
    #endif
    }
    // Turn off ADC
    ADC_off();

    // Charge up the capacitor by setting CAP_PIN to output
    DDRB  |= (1 << CAP_PIN);    // Output
    PORTB |= (1 << CAP_PIN);    // High

    // Set PWM pin to output
    DDRB |= (1 << PWM_PIN);
    #ifdef DUAL_PWM_START
    DDRB |= (1 << STAR2_PIN);
    #endif

    // Set timer to do PWM for correct output pin and set prescaler timing
    TCCR0A = 0x23; // phase corrected PWM is 0x21 for PB1, fast-PWM is 0x23
    TCCR0B = 0x01; // pre-scaler for timer (1 => 1, 2 => 8, 3 => 64...)

    // Turn features on or off as needed
    #ifdef VOLTAGE_MON
    ADC_on();
    #else
    ADC_off();
    #endif
    ACSR   |=  (1<<7); //AC off

    // Enable sleep mode set to Idle that will be triggered by the sleep_mode() command.
    // Will allow us to go idle between WDT interrupts
    set_sleep_mode(SLEEP_MODE_IDLE);

    uint8_t prev_mode_idx = mode_idx;

    WDT_on();

    // Now just fire up the mode
    // Set timer to do PWM for correct output pin and set prescaler timing
    if (modes[mode_idx] > FAST_PWM_START) {
        #ifdef DUAL_PWM_START
        TCCR0A = 0b10100011; // fast-PWM both outputs
        #else
        TCCR0A = 0b00100011; // fast-PWM normal output
        #endif
    } else {
        #ifdef DUAL_PWM_START
        TCCR0A = 0b10100001; // phase corrected PWM both outputs
        #else
        TCCR0A = 0b00100001; // phase corrected PWM normal output
        #endif
    }
    TCCR0B = 0x01; // pre-scaler for timer (1 => 1, 2 => 8, 3 => 64...)

    set_output(modes[mode_idx]);

    uint8_t i = 0;
    uint8_t hold_pwm;
    while(1) {
    #ifdef VOLTAGE_MON
        if (low_voltage(ADC_LOW)) {
            // We need to go to a lower level
            if (mode_idx == 0 && ALT_PWM_LVL <= modes[mode_idx]) {
                // Can't go any lower than the lowest mode
                // Wait until we hit the critical level before flashing 10 times and turning off
                while (!low_voltage(ADC_CRIT));
                i = 0;
                while (i++<10) {
                    set_output(0);
                    _delay_ms(250);
                    set_output(modes[0]);
                    _delay_ms(500);
                }
                // Turn off the light
                set_output(0);
                // Disable WDT so it doesn't wake us up
                WDT_off();
                // Power down as many components as possible
                set_sleep_mode(SLEEP_MODE_PWR_DOWN);
                sleep_mode();
            } else {
                // Flash 3 times before lowering
                hold_pwm = ALT_PWM_LVL;
                i = 0;
                while (i++<3) {
                    set_output(0);
                    _delay_ms(250);
                    set_output(hold_pwm);
                    _delay_ms(500);
                }
                // Lower the mode by half, but don't go below lowest level
                if ((ALT_PWM_LVL >> 1) < modes[0]) {
                    set_output(modes[0]);
                    mode_idx = 0;
                } else {
                    set_output(ALT_PWM_LVL >> 1);
                }
                // See if we should change the current mode level if we've gone under the current mode.
                if (ALT_PWM_LVL < modes[mode_idx]) {
                    // Lower our recorded mode
                    mode_idx--;
                }
            }
            // Wait 3 seconds before lowering the level again
            _delay_ms(3000);
        }
    #endif
        sleep_mode();
    }

    return 0; // Standard Return Code
}