def get_voltage(self, channel, unit='V'):
        '''Reading voltage
        '''
        kwargs = self._ch_map[channel]['ADCV']
        voltage_raw = self._get_adc_value(**kwargs)

        voltage = (voltage_raw - self._ch_cal[channel]['ADCV']['offset']) / self._ch_cal[channel]['ADCV']['gain']

        if unit == 'raw':
            return voltage_raw
        elif unit == 'V':
            return voltage
        elif unit == 'mV':
            return voltage * 1000
        else:
            raise TypeError("Invalid unit type.")
Reading voltage