def refbasis(reading,ref):
	"""Argument: raw ADC reading, raw ADC basis.  Returns an absolute potential based on the ADC reading against the 2.5 V reference
	   (reading from pot as a value between 0 and 1023, reference value in V (e.g. 2.5))"""
	return round((float(reading)/float(ref))*2.5,3)