Im trying to measure temperature using PT100. Im using ADC Pi board for that. ADC Pi uses MCP3424(pdf datasheet) A/D converters, and in datasheet I found how to calculate voltage - it is pretty simple -
Input Voltage = (Output Code) * LSB/PGA
So i made a simple app which would get the output code, calculate voltage, and from that voltage calculate resistance. But the result was not right. So I searched the sample codes and found out that the calculation is a little bit different -
voltage = float( (raw * (self.__lsb / self.__pga)) * 2.448579823702253)
I was not able to find out what the number
2.448579823702253 means... I assume it has something to do with other parts on the board, but i dont really understand electronics so good.
Can someone explain what exactly does it mean?