battery.py

from machine import ADC, Pin


class Battery:
    """ Read battery status from input source
    """
    def __init__(self, adc: int, min_value: float = 6.4, max_value: float = 8.4):
        self.adc = ADC(Pin(adc))
        self.adc.atten(ADC.ATTN_11DB)
        self.min = min_value
        self.max = max_value

    def status(self) -> dict:

        voltage_sum = 0
        for i in range(20):
            voltage_sum += self.adc.read()

        voltage = (voltage_sum / 20) / 3134 * self.max
        percentage = 0 if voltage < self.min else (voltage - self.min) / (self.max - self.min) * 100

        return {
            'voltage': round(voltage, 2),
            'percentage': round(percentage, 2)
        }