code: def setDigitalMinimum(self, edfsignal, digital_minimum):
          
          if (edfsignal < 0 or edfsignal > self.n_channels):
              raise ChannelDoesNotExist(edfsignal)
          self.channels[edfsignal]['digital_min'] = digital_minimum
          self.update_header()
docs: Sets the minimum digital value of signal edfsignal.
          Usually, the value -32768 is used for EDF+ and -8388608 for BDF+. Usually this will be (-(digital_maximum + 1)).
  
          Parameters
          ----------
          edfsignal : int
              signal number
          digital_minimum : int
              Sets the minimum digital value
  
          Notes
          -----
          This function is optional and can be called only after opening a file in writemode and before the first sample write action.