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Help: Arduino + MAX31855 (TC amplifier) + 4051 Multiplexer(s)


Jun 10, 2014
Jun 10, 2014

I am trying to design a simple data collection system using thermocouples to take temperature measurements. To reduce costs of multiple thermocouple amplifiers, I intend to use a multiplexer to take in the multiple (8) thermocouples and feed into a single thermocouple amplifier.

I'm fairly new to electronics, would like help to better understand how one would connect the 8:1 multiplexers to the MAX31855 and Arduino UNO.

From my understanding, one multiplexer would take in the positive leads of the thermocouples and another multiplexer would take in the negative leads into the 8 analog inputs. Then the multiplexers each would send one analog output (one positive and one negative) to the terminal of the thermocouple amplifier which then connects to the arduino.

But what about the select pins? Those connect to the arduino, right? (see here:

Here are the components:
Thermocouple Amplifier MAX31855:
4051 Multiplexer:


PS. I have also seen/read of designs that have 8-channels (8 thermocouples) with a single multiplexer, although I have no clue on how that works...