s32k358 MCU temperature measurement

[BillWen]

Hi :

I have some problem on measure s32k358 mcu temperature, I also check other post on NXP community, but I can't find the problem, please help us check, thanks.

The following is my ADC setting :

Function code I follow the formula from S32K3RM

I get Mcu temp raw data about 8208, and after ADC 8208* (3300/16384)

and formula from RM then can get MCU temp = 48~49, I think the value is not correct.

Is there any wrong setting in my MCAL or code?

Thanks

BR, BillWen

[Senlent]

Hi@BillWen

First, the calculation process you provided is correct, but I see some obvious errors:

1. The parameter you entered here is 53, which is 0b00110101.

This indicates that the reference voltage is 3.5V, not 3.3V.

So this should be wrong :ADC 8208* (3300/16384)

---------------------------------------------------------------------------------

I've created a simple table based on the calculation formulas provided in the datasheet for your reference.

[BillWen]

Hi Senlent:
Thanks for your reply.
For the parameter you entered here is 53, which is 0b00110101.
I change the value to 3.3V(51) or 5V(80), I still get the same raw data. I use the same way to get mcu temp just like how I get other ADC value, is it correct? or do I need to use Adc_TempSenseGetTemp function?

Thanks
BR,BillWen

[Senlent]

Hi@BillWen

I think that's incorrect, because this should change.

Have you enabled the internal temperature sensor?

It's not mandatory, but our driver already provides an API for calculation.

You can refer to this example.

https://community.nxp.com/t5/S32K-Knowledge-Base/Example-S32K344-TempSenser-S32DS36-RTD600-500-400-p...

[BillWen]

Hi Senlent:
As I know is that we can use Adc_TempSenseGetTemp API to get the temperature value after convert, but I also can convert by myself, right? I also check the following post on community. It seems that I still can just get rawdata and use formula from Reference manual to calculate the real temperature value.
https://community.nxp.com/t5/S32K/Reading-the-internal-temperature-of-S32K388-using-TEMPSENSE/m-p/18...

Btw, I also check the example you uploaded, due to the project is based on driver layer not MCAL layer, I think is different process.
Thanks
BR, BillWen

[Senlent]

Hi@BillWen

Yes, you can calculate it yourself, but since an API has been provided, there's no need to do it manually.

[BillWen]

Hi Senlent:

Yes, I know this, but the problem for now is that I can't get right raw data. The real temperature value won't be correct no matter calculate by API or manually if the raw data not correct.

Thanks
BR, BillWen

[Senlent]

Hi@BillWen

1. Check if the internal temperature sensor is enabled.

2. Check if the ADC is configured correctly.

If the sampling values ​​of your other ADC channels are correct, there's no reason why the temperature sensor's sampling value shouldn't change at all.

[BillWen]

Hi Senlent:
I think ADC configuration is correct because I can get correct other ADC value correct like power voltage which according to our project.
Do you know how to check internal temperature sensor is enabled or not?
Thanks
BR, BillWen

[Senlent · Accepted solution]

Hi@BillWen

The TEMPSENSE output can be read by an ADC on demand so that the software can determine the current die temperature. The software should enable the TEMPSENSE by setting ETSCTL[ETS_EN].

Secondly, there are requirements for the ADC sampling time of the temperature sensor; it must be greater than 1.2us. I suggest you use a larger value.

[BillWen]

Hi Senlent:
Thanks for your support, I find the problem.
After I fix my problem, I get the temperature around 35~36, it seems normal I think.

Thanks
BR, BillWen

[Senlent]

Hi@BillWen

If this post answers your question, please click the "ACCEPT AS SOLUTION" button.