#include "main.h"


// arrays to hold strings for LCD
static char lm35_string[17];
static char diode_string[17];

/** @brief Initialises general pins for use.
 * 
 * @note Does not initialise LCD pins. That is handled by lcdlibrary
 */
void pin_init() {
    /* Pin Mappings:
     * PC0 -> ADC0 input for diode measurement
     * PC1 -> ADC1 input for LM35
     */

    // Pin Config for Diode ADC
    DDRC &= ~(1 << DDC0);
    DIDR0 |= (1 << ADC0D); // Disable digital input

    // Pin Config for LM35 ADC
    DDRC &= ~(1 << DDC1);
    DIDR0 |= (1 << ADC1D); // Disable digital input
}

/** @brief Initializes ADC with required settings
*/
void adc_init() {
    /* ADC Settings
     * Use 1v1 reference as Vref
     * Initially set input as GND
     * Data right-adjusted
     * No Interrupts
     */
    // Set Vref
    ADMUX |= (1 << REFS1) | (1 << REFS0);
    // Set the clock prescaler to 128 (slower ADC means more accurate measurements)
    ADCSRA |= (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0);

    // Enable ADC
    ADCSRA |= (1 << ADEN);
}

/** @brief Blocking function to read an ADC conversion from a selected ADC input.
 * 
 * @note Blocks until conversion finishes, so speed of this function is dependant
 *      on ADC prescaler.
 * 
 * @param adc_selection Value from 0-5, selects from ADC[0-5]
 * 
 * @return Raw value of ADC conversion
 */
uint16_t adc_run_conversion(uint8_t adc_selection) {
    // Select ADC input, using 
    ADMUX = (ADMUX & 0xF0) | (0x0F & adc_selection);

    // Start conversion
    ADCSRA |= (1 << ADSC);

    // Wait until conversion is complete
    while (!(ADCSRA & (1 << ADIF)));

    // Read out conversion value
    return ADC;
}


/** @brief Converts an ADC value from a measurement on an LM35 into a temperature.
 * 
 * @param adc_reading Raw ADC measurement from LM35.
 * 
 * @return Measured temperature, configure parameters in main.h
 */
int8_t lm35_convert(uint16_t adc_reading) {
    return (adc_reading * ADC_VREF / ADC_RESOLUTION) / LM35_SENSITIVITY;
}

/** @brief Converts and ADC value from a measurement on a diode into a temperature.
 * 
 * @param adc_reading Raw ADC measurement from diode.
 * 
 * @return Measured temperature, configure parameters in main.h
 */
int8_t diode_convert(uint16_t adc_reading) {
    int16_t value_diff = adc_reading - DIODE_VALUE_25C;
    int16_t temp_diff = value_diff / DIODE_SENSITIVITY;
    return temp_diff + 25;
}

int main() {
    // Initialise display
    // NOTE: LCD uses PB0-PB6
    lcd_init(LCD_DISP_ON);

    // Initialise peripherals
    pin_init();
    adc_init();



    while (1) {
        // Reset position
        lcd_gotoxy(0, 0);

        // Read LM35 value, and write to LCD
        uint16_t lm35_value = adc_run_conversion(1);
        int8_t lm35_temp = lm35_convert(lm35_value);
        // Convert measured value to string
        sprintf(lm35_string, "LM35 : %4d %3dC", lm35_value, lm35_temp);

        // Display temp on LCD
        lcd_puts((const char*) lm35_string);

        lcd_gotoxy(0, 1);


        // Read diode value, and write to 
        uint16_t diode_value = adc_run_conversion(0);
        int8_t diode_temp = diode_convert(diode_value);
        sprintf(diode_string, "Diode: %4d %3dC", diode_value, diode_temp);

        // Display diode info on LCD
        lcd_puts((const char*) diode_string);

        // Refreshing too fast can make the data appear weird
        _delay_ms(500);
    }

}