DLPC3479: Temperature reading error

junfa ye

Part Number: DLPC3479
Other Parts Discussed in Thread: DLPC3478, , DLPA3005, DLPA3000

Tool/software:

Hello, Ti team.

We found that in the GUI, reading this temperature was wrong.

The driving board is designed with reference to the EVM board. The temperature reading circuit has confirmed that there is no problem,

but it is 204 degrees every time it is read back.

Moreover, I tried to change the NTC resistor into an adjustable resistor.

The voltage ranged from 0 to 0~1.8V, and it was all 204 degrees after reading. Replacing other driver boards is the same mistake.

The firmware version we used was established by ourselves, including 8.3 and the latest 8.4 version, including 8.0, but it was read incorrectly.

In addition, we also downloaded the version downloaded by TI.COM, which is also a reading error, as shown below.

But in our DLPC3478 driver board, the temperature read back is correct.

So we suspect that there is a bug in the firmware, please solve it, thank you!

2 months ago

0 Tristan Bottone 2 months ago

TI__Intellectual 1070 points

Good afternoon junfa ye,

Thank you for reaching out and using the E2E forums! An expert from our team will review the thread and get back to you shortly.

Regards,

Tristan Bottone

0 Aaron Black 2 months ago in reply to Tristan Bottone

TI__Genius 9130 points

Hello Junfa Ye,

It seems you are using quite an old GUI software, could you please update to the latest - v3.2.0.7 - here.

Best,

Aaron

0 junfa ye 2 months ago in reply to Aaron Black

Prodigy 170 points

Hello Aaron,

This should be irrelevant, because the value I read from the register is also wrong.
I use the latest version of GUI, as shown below, and the reading is also wrong.

0 Aaron Black 2 months ago in reply to junfa ye

TI__Genius 9130 points

Hello Junfa Ye,

The max readback for system temperature is an 204.7°C (0x7FF [2047/10]).

What NTC thermistor do you have connected to the system GPIO_11 (DLPC3479) and / ACMPR_IN_2?

Please advise if you are using DLPA3005 or DLPA3000?

Sorry, I need more details to understand what's happening here.

Best,

Aaron

0 junfa ye 2 months ago in reply to Aaron Black

Prodigy 170 points

Hello Aaron,

The design is based on EVM, as follows,

The NTC thermistor used is NCP15WF104F03RC, and DLPA3005 is used.

0 Aaron Black 2 months ago in reply to junfa ye

TI__Genius 9130 points

Hello Junfa Ye,

Thank you for confirming this. Could you probe both TP169 and TP170 to see what is being sent from either end? It's seeming to be held high and receiving all 1's.

Best,

Aaron

0 junfa ye 2 months ago in reply to Aaron Black

Prodigy 170 points

Hello Aaron,

It has been measured that there is a fixed voltage value of 1.1V on both sides.

The register values read by GUI are 0xff and 0x07, that is, 0111 1111 1111.

The resistance value of the over-pull-down is also changed, that is,

the voltage is changed to 0~1.8V, but it is still all 1s after reading.

As shown below:

0 Aaron Black 2 months ago in reply to junfa ye

TI__Genius 9130 points

Hello Junfa Ye,

I can send you a version that has worked with others.

Please accept my connection request, I'm not sure if it is sent to you properly, my browser was froze and gave an error.

Please also advise what pin mapping you are utilizing, EVM default is Option 2 but it was mentioned before you possibly had your own solution.

Best,

Aaron

0 junfa ye 2 months ago in reply to Aaron Black

Prodigy 170 points

Hello Aaron,

Ok, I saw you on my friends list.

The configuration used by the firmware is: 3479, 3005, and the DMD pin is Option 1.

0 Aaron Black 2 months ago in reply to junfa ye

TI__Genius 9130 points

Hello Junfa Ye,

Thanks for confirming, I'll get this to you and we will take this off of E2E.

If more is learned I will add to this thread.

Best,

Aaron

+1 Aaron Black 1 month ago in reply to Aaron Black

TI__Genius 9130 points

Coming back to this thread and closing it:

Findings were that the because the ACMPR_OUT pin was not connected the readings were not being read correctly to the PMIC.

After connecting SENS2 line to ACMPR_OUT pin temperature was seen accurately.

Best,

Aaron

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DLPC3479: Temperature reading error