Decode ADC Result Using Union Bitfields

Code

#include <stdio.h>
#include <stdint.h>

typedef union {
    struct {
        uint16_t adc_value : 12;
        uint16_t channel   : 4;
    };
    uint16_t adc_reg;
} ADC_Result;

void fill_adc(uint16_t reg){
    ADC_Result ar;
    ar.adc_reg = reg;

    printf("Channel: %u\n", ar.channel);
    printf("ADC Value: %u", ar.adc_value);
}

int main() {
    uint16_t reg;
    scanf("%hx", &reg);

    fill_adc(reg);

    // Fill union and print channel and adc_value
    return 0;
}

Solving Approach