LAUNCHXL-F28069M: LAUNCHXL-F28069M:

Lakshmi Santosh1

I purchased a LaunchXL-F28069M kit for my coursework in March 2017. The later lab assignments involved measuring temperature. I noticed that the kit puts out 0-2C even at room temperature. But when I heat up the unit or cool it, the temperature goes up and down relatively. The board seems normal to me otherwise. Could this be a bad hardware or is there a settings issue?

Thanks,

Lakshmi

over 8 years ago

0 Kash Olia over 8 years ago

Genius 3215 points

Lakshmi,

The onboard temperature sensor measures the junction temperature of the MCU. There is a offset which is defined as the 0 C LSB crossing, I assume you didn't consider the offset, check page 522 of the following manual:

http://www.ti.com/lit/ug/spruh18g/spruh18g.pdf

--Regards,

0 Lakshmi Santosh1 over 8 years ago in reply to Kash Olia

Prodigy 215 points

This was a sample code from the professor which works fine on others kits. The problem is only with my kit.

Lakshmi

0 Mark Labbato over 8 years ago in reply to Lakshmi Santosh1

Guru 30330 points

Lakshmi,

Please correct me if I am misunderstanding: Your board has a consistent offset at room temperature? Is your code different from what is running on the other kits? can you load and run a .out file that was loaded to another?

Thanks,
Mark

0 Lakshmi Santosh1 over 8 years ago in reply to Mark Labbato

Prodigy 215 points

Even the raw data from the sensor indicates the temperature shown is incorrect. I will however try to load a known good .out file.

Thanks,
Lakshmi

0 Mark Labbato over 8 years ago in reply to Lakshmi Santosh1

Guru 30330 points

Lakshmi,

Any update on this?

-Mark

0 Lakshmi Santosh1 over 8 years ago in reply to Mark Labbato

Prodigy 215 points

Thanks for your reply Mark. It turned out to be an offset issue. The original code was meant for TMX silicon and the board I have has TMS silicon. After replacing the formula for slope and offset, the results improved. Its still not perfect (get 35C for room temperature). I probably need to check the calibration and recheck the offset/slope formula's. But I now that the board is in good condition.

Lakshmi

0 Mark Labbato over 8 years ago in reply to Lakshmi Santosh1

Guru 30330 points

Great. Glad to hear that you have a path moving forward. I am going to close this post. If you have additional questions in the future, please do not hesitate to create a new thread.

Happy Coding!
Mark

C2000™︎ microcontrollers

C2000 microcontrollers forum

LAUNCHXL-F28069M: LAUNCHXL-F28069M:

http://www.ti.com/lit/ug/spruh18g/spruh18g.pdf