Interfacing temperature sensor and ohm meter with arduino mega

Hi everyone,

I am currently working on a project where I need to measure the resistance of a material with increasing temperature (35oC to 100oC). Presently, I am measuring the resistance using a Keithley 2002 multimeter and varying the temperature using a setup containing a voltage controller. The drawback of the current way of measuring is that I have to be present throughout the experiment and note down the corresponding resistance reading for each 5oC increase in temperature, which is quite hectic. So, I was thinking of developing an ohm meter using Arduino mega and interfacing a temperature sensor with it. Therefore, can anyone of you guys can help me building the code for measuring the resistance for every 5oC rise in temperature. And, also I need the output of the result in excel format.

Note: Using ADS1115 ADC, I have already build ohm meter which can accurately measure the resistance of the material.

is the ohm meter you have built using a ADS1115 ADC based on an arduino ? for example using a https://www.adafruit.com/product/1085 once you have acquired the data on the arduino you could transmit it over a serial line to a PC to be processed by Excel

Showing data for every 5 degree increase is easy, can be done like this:

target = 35;
void loop() {
  float temp = readTemp();
  float resistance = readResistance();
  if (temp > target) {
    Serial.print("Temp: ");
    Serial.println(temp);
    Serial.print("Resistance: ");
    Serial.println(resistance);
    target += 5;
  }
}

The multimeter you are using is far superior to anything that you will build yourself using an Arduino.

You can control it and take readings via GPIB. I'm not sure how easy that would be using an Arduino., but USB-GPIB Controllers are readily available.

horace: is the ohm meter you have built using a ADS1115 ADC based on an arduino ? for example using a https://www.adafruit.com/product/1085 once you have acquired the data on the arduino you could transmit it over a serial line to a PC to be processed by Excel

Yes, it is based on ADS1115 ADC. Thanks for the info.

JohnLincoln:
The multimeter you are using is far superior to anything that you will build yourself using an Arduino.

You can control it and take readings via GPIB. I’m not sure how easy that would be using an Arduino., but USB-GPIB Controllers are readily available.

Yes, I am well aware of this. Using USB-GPIB controller, I can get the data from the multimeter. But the problem is to connect both multimeter and temperature controller/ with PC and make the whole process automated.

wvmarle: Showing data for every 5 degree increase is easy, can be done like this:

target = 35;
void loop() {
  float temp = readTemp();
  float resistance = readResistance();
  if (temp > target) {
    Serial.print("Temp: ");
    Serial.println(temp);
    Serial.print("Resistance: ");
    Serial.println(resistance);
    target += 5;
  }
}

Thanks for the codes.

A little modification and you have it for every 1 degree. You can always discard the extra data later if you really don't want it :-)