#define RCC_BASE 0x40021000
#define ADC_BASE 0x40012400

#define RCC_APBENR2 (*((volatile uint32_t*)(RCC_BASE + 0x40)))
#define ADC_ISR (*((volatile uint32_t*)(ADC_BASE + 0x00)))
#define ADC_CR (*((volatile uint32_t*)(ADC_BASE + 0x08)))
#define ADC_CFGR2 (*((volatile uint32_t*)(ADC_BASE + 0x10)))
#define ADC_SMPR (*((volatile uint32_t*)(ADC_BASE + 0x14)))
#define ADC_CHSELR (*((volatile uint32_t*)(ADC_BASE + 0x28)))
#define ADC_DR (*((volatile uint32_t*)(ADC_BASE + 0x40)))

#define RCC_APBENR2_ADCEN (1<<20)
#define ADC_CR_ADEN       (1<<0)
#define ADC_CR_ADCAL      (1<<31)
#define ADC_CFGR2_CKMODE  (1<<30)
#define ADC_CHSELR_CHSEL0 (1<<0)
#define ADC_SMPR_SMP_1_5  0       //(0<<0);
#define ADC_CR_ADSTART    (1<<2)
#define ADC_ISR_ADRDY     (1<<0)
#define ADC_ISR_EOC       (1<<2)

void ADC_Init(void) {
    // Enable ADC clock
    RCC_APBENR2 |= RCC_APBENR2_ADCEN;

    // Calibrate ADC
    ADC_CR &= ~ADC_CR_ADEN;         // Ensure ADC is disabled
    ADC_CR |= ADC_CR_ADCAL;         // Start calibration
    while (ADC_CR & ADC_CR_ADCAL);  // Wait for calibration to complete

    // Configure ADC
    ADC_CFGR2 &= ~ADC_CFGR2_CKMODE; // Use HCLK/1
    ADC_CHSELR = ADC_CHSELR_CHSEL0; // Select channel 0
    ADC_SMPR = ADC_SMPR_SMP_1_5;    // Set sampling time to 1.5 ADC clock cycles

    // Enable ADC
    ADC_CR |= ADC_CR_ADEN;          // Enable ADC
    while (!(ADC_ISR & ADC_ISR_ADRDY)); // Wait until ADC is ready
}

uint16_t ADC_Read(void) {
    ADC_CR |= ADC_CR_ADSTART;       // Start conversion
    while (!(ADC_ISR & ADC_ISR_EOC)); // Wait for conversion to complete
    return ADC_DR;                  // Return the ADC result
}

int main(void) {
    ADC_Init(); // Initialize ADC
    Serial.begin(115200);

    while (1) {
        uint16_t adc_value = ADC_Read(); // Read ADC value
        // Use adc_value (e.g., for processing or debugging)
        Serial.println(adc_value);
    }
}