CN-0545 Thermistor AD7124 Eval+

Hi

Apologies for this. We will raise this with our software team and get back to you. 

Thanks,

Jellenie

Hi Jellenie,

Thank for your feedback.

Please kindly advise ADI most update version of Eval+ SW with thermistor demo

So that, we would like to achieve the following test.

https://wiki.analog.com/resources/eval/user-guides/circuits-from-the-lab/cn0545?doc=CN0545.pdf

Thank you.

Mark

Hi Jellenie,

While we are waiting for the software team feedback, could you advise the CN-0545 design file?

I would like to download CN-0545 design file following, but the link is not valid

https://www.analog.com/cn0545-designsupport

https://wiki.analog.com/resources/eval/user-guides/circuits-from-the-lab/cn0545

Besides, might I know if ADI has any reference thermistor code for AD7124? We would like to study the way AD7124 eval SW working with Thermistor Transfer Function.

Appreciate your help in advance.

Thank you.

Mark

Hi, 

We have requested to upload the latest version of the software which includes the thermistor demo mode. The latest version is v1.4.2.17. The system will need 2-3 days before it become available on the AD7124-4/8 Product pages. 

In terms of the hardware files. 

https://www.analog.com/media/en/reference-design-documentation/design-integration-files/CN0381-CN0383-CN0384-DesignSupport.zip 

I think you need to fill up the form before you will be able to download the files. However,  CN0545 uses the EVAL-AD7124-8 Evaluation Board | Analog Devices/EVAL-AD7124-4 Evaluation Board | Analog Devices so you can also view the schematic and layout along with the BOM on its UG.

In terms of the sensor, I have used Omega 44031 NTC thermistor. Have you also tried to use this tool? It will help you configure your thermistor circuit design using AD7124 along with the calculation of expected performance. If you can try it and also provide any feedback then that would be nice. 

Thermistor Configurator and Error Budget Calculator 

Thanks,

Jelllenie

Hi Jellenie,

Thank for your help. I will be looking forward to the new update version is v1.4.2.17

Yes, I downloaded the thermistor configurator tools. It is a powerful tools.

It recommend the resistor value, Temp code in Hex and operation range. Very convenient

I am really appreciated. High recommended!

By the way, do you have advice for converting ADC value to temperature in code? The thermistor calculation require Steinhart-Hart / beta equation and natural logarithm.

I am wondering the methods to translate math formula into a C code.

Thank for your help in advance.

Thank you.

Mark

Hi Mark, 

If you will noticed on the last tab of the tool there is a link for a temperature firmware code. That code is written in C and these codes includes the linearization equations for each temperature sensor which includes thermistor. The code used mbed platform which can be use across multiple controllers. 

Just to add, looks like the Eval+ software is now updated. Please download it in this link.

https://www.analog.com/media/en/evaluation-boards-kits/evaluation-software/ad7124-eval-plus-installer.zip 

Thanks,

Jellenie