LPC55S28 internal temperature sensor calculation

[schmalen]

Hi, 

I would like to read the temperature of the mcu using the internal temperature sensor. I found the formula for calculating the temperature in the user guide. The formula requires four measurements in total. I would like to use the hardware comparator to set a temperature threshold so I don't have to calculate and check the temperature manually.

I thought about averaging the adc values automatically so the offset or change of the analog value at the beginning does not matter that much. How do I have to modify the formula for calculation? Unfortunately, there is no sdk example for the lpc55s28 and I don't have that much time to figure it out for myself. 

Best regards, 
Fabian

[_Leo_]

Hi,

Thank you so much for your interest in our products and for using our community.

Sorry, we do not have the example code that you require for LPC55xx devices. What you can do is take as reference the temperature monitor examples for other devices.

You can found them in the in the following way:

1. Go to https://mcuxpresso.nxp.com/en/welcome page.
2. Click in "Select Development Board".
3. Click in "Required Example Projects".
4. Input "temp" in "Extended search".
5. You will find a list with different examples.
6. Select one of them.
7. And then click in "Continue with Examples selected below".

Hope it helps you.

Have a nice day!

[schmalen]

Hi,
Thanks for helping. Unfortunately, I did not find an example that is compatible with the LPC55S28 following your recommendation. When searching for "temp" and selecting the lpadc example, I am able to choose between some LPC boards but not an LPC55S28. Clicking other example doesn't give me any LPC MCUs for selection.

Best regards,
Fabian

[_Leo_ · Accepted solution]

It is correct, as I mentioned before, we do not have the example code that you require for LPC55xx devices. The examples that I recommend you are just for references. Please accept my apologies for the inconvenience. 

[schmalen]

Ah sorry, I think I misunderstood. I thought there was a "secret repository" anywhere that had the missing example program. 

If I have time, I will try to adapt the code example. 

As a conclusion:
It is not currently possible to use automatic averaging in the LPC55S28 with a known adaption of the formula for calculation. That has to be done manually by testing. 

Best regards, 

Fabian