DLP3030-Q1: Read and Verifying VLED Current and Voltage from TMS320F2803x Piccolo SPI and DLPC120 SPI interface

Sundar Vinayagam

Part Number: DLP3030-Q1

Hi, I am trying to implement the read SPI command for VLED voltage and current (C5h) from TMS320F Piccolo and DLPC120. I am getting 4+4 byte Raw data (Voltage and Current).

I used the float conversion as mentioned in "DLPCU061_piccolo_SW_Guide_2018", But I could not read any proper voltage or current value. I could not see any variation in voltage or current even, If I change the input supply or changing the brightness.

Also I need to know, how can I measure the actual measurements and compare with the obtained raw value. our aim is to read the over voltage and over current please suggest if there is any other method to read.

9 months ago

0 Austin Snyder 9 months ago

TI__Genius 12595 points

Hello User,

Welcome to the E2E forum and thank you for your interest in DLP® technology.

Would you mind sharing the raw data that you have received as we look over how to interpret this data?

Kind regards,

Austin

0 Sundar Vinayagam 9 months ago in reply to Austin Snyder

Intellectual 455 points

Hello Austin,

I am getting the below response for voltage and current.

0 Lori Wang 9 months ago in reply to Sundar Vinayagam

TI__Expert 7930 points

Hello User,

Thank you for the information!

We will look into this and get back to you in a few days.

Regards,

Lori

0 Sundar Vinayagam 9 months ago in reply to Lori Wang

Intellectual 455 points

Hi Lori Wang,

Any Updates on above query?

I referred the Help section of "DLPC120 Automotive control program" software, under Lua scripting documentation we found that need to configure register of ASIC chip as shown in below image.

kindly share more information regarding this.

0 Lori Wang 9 months ago in reply to Sundar Vinayagam

TI__Expert 7930 points

Hello User,

We can replicate this issue and we also noticed the lua function of the HUD_GerLEDVI() may not working. Unfortunately, we currently do not have a plan to fix this issue.

Apologize for the inconvenience.

Regards,

Lori

0 Sundar Vinayagam 8 months ago in reply to Sundar Vinayagam

Intellectual 455 points

Hello Austin,

How about the above response, is this a valid one?. On what basis the current and Voltage will change. We tried varying input voltage as well as brightness, the response is not varying.

0 Sundar Vinayagam 8 months ago in reply to Lori Wang

Intellectual 455 points

Hi Austin/Lori

Need quick support here. we are stuck here and unable to proceed.

Giving summary of issue again.

Our HUD is connected to TMS320 F28023 using SPI.

Using SPI read command for VLED voltage and current (C5h) from TMS320F Piccolo and DLPC120 as below.

I am getting 4+4 byte Raw data (Voltage and Current) response as below

Above values are not changing if change in supply voltage from 8.5v to 18V. Not clear if data is correct or not.

we are seeing same values always.

can you support why the values are not changing and any other settings needed ?

0 Lori Wang 8 months ago in reply to Sundar Vinayagam

TI__Expert 7930 points

Hi User,

We tested on the TI EVM and replicated the same behavior as you mentioned that the read LED voltage and current command 0x62 does not change. Unfortunately, we do not have a short plan to fix this issue.

If you are worried about the LED current will exceed the limit, then the reference design mentioned the 3.3 A limit for the RGB LEDs if you followed the design instruction.

Regards,

Lori

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DLP3030-Q1: Read and Verifying VLED Current and Voltage from TMS320F2803x Piccolo SPI and DLPC120 SPI interface