ADS1243 Guide on using as thermocouple amplifier

Other Hardware General Electronics
1

Hello to everybody. I don't want to ask anything. Simply to share and help others in using a 24 bit ADC ADS1243 for high precision temperature measurements using arduino and a platinum platinum-rhodium thermocouples used in metal production for thermal processing iron parts to harden them.

The connection is simple

Pin outs

ADS1243 | Arduino

MISO | PB3 - 50
MOSI | PB2 - 51
SCK | PB1 - 52
CS | PB0 - 53
DRDY | PL1 - 48
PDWN | PL3 - 46

The ADC uses SPI communication. I started the project on Arduino Mega R3 so I used the corresponding pins on bottom part of board to easily connect a custom PCB for the ADC i made.
You are free to try other pins and connection types of course :)

The code part (is to big, posting as a separate file)

The code example has comments. All the addresses and the register values where taken from the official datasheet of Texas Instruments.

ADS 1243 datasheet PDF

Hope this will help others in their research work.

ADS1243.ino (14.6 KB)

2

But don't forget about reference junction compensation, the connection from thermocouple wire to copper terminal will cause an error if not compensated.

3

It is always an option to use thermocompensation wires to transmit the signal from the thermocouple source to the adc for instance if the heater is to hot and it is not possible to put the thermoregulator with the arduino close to the metal hardening oven.

4

I am planning to use this ADC with a MCU for temperature measurement with a precision of 10uV. The data accuracy is very critical.

Can somebody provide some information about the front-end components like, resistor divider, op-amp follower, zenner diode etc., if required? How to feed the VREF+ and VREF-.

Looking for some help to decide on the components.

Thanks in advance !