DLP4710: Trigger Sequence of patterns from camera

Ritaban Chowdhury

Part Number: DLP4710
Other Parts Discussed in Thread: DLPC3439

Hi,

I am relatively new to DLP Lightcrafter 4710. For my 3D scanner application I need to trigger the projector through camera. How do I do that?

over 6 years ago

0 Sepeedah Zadeh over 6 years ago

TI__Intellectual 2850 points

Hello Ritaban,

Thanks for your interest in DLP products. Are you using the DLP4710_G2 EVM? If so please refer to a similar post which mentions how to use the triggers to sync a camera:

Also note that the DLP4710 is targeted at display applications and some processing is done to make images look better, therefore it's not pixel accurate. For a 3D scanner application I would recommend looking into our Advanced Light Control products which are pixel accurate and there are designs online for your application using these products, for example:

You can also refer to the E2E Advanced Light Control Forum for more support on these parts. Hope this helps.

Best,

Sepeedah

0 Ritaban Chowdhury over 6 years ago in reply to Sepeedah Zadeh

Prodigy 120 points

Dear Sepeedah,
Thanks for the quick response. I saw that document after posting the question. Now, I have a new problem. I was using bat file to program GPIO Pins. When I write GPIO controls using W 36 31 .. and try to read it with R 32 I get back the numbers I wrote. If I give read command again in next line I get all 0. Do you have any idea why ?
Regards,
Ritaban.

0 Sepeedah Zadeh over 6 years ago in reply to Ritaban Chowdhury

TI__Intellectual 2850 points

Ritaban,
Can you try the read command with R 37 32 and see what you get?

Thanks,
Sepeedah

0 Ritaban Chowdhury over 6 years ago in reply to Sepeedah Zadeh

Prodigy 120 points

I did it's giving me bunch of 0's.

0 Sepeedah Zadeh over 6 years ago in reply to Ritaban Chowdhury

TI__Intellectual 2850 points

I'm not sure why this is happening. My guess is the I2C read command reads whatever has been last written to the device. Therefore when you issue two back to back read commands basically there hasn't been any write command before the second read, so it reads 0. Is there a reason that you need to do a redundant read command?
Can you please explain in more detail what you are trying to accomplish? Also what tools are you using? Is it the 4710-G2 EVM with the Lightcrafter GUI?

Thanks,
Sepeedah

0 Ritaban Chowdhury over 6 years ago in reply to Sepeedah Zadeh

Prodigy 120 points

I don't need two reads back to back I was just curious to see what happens. My goal is to get signal from the camera to tell the projector to start projecting patterns. After the first pattern is projected it should signal the camera to capture it and then projector needs go to the next pattern and so on. For that I need to read and write from Trigger gpio pins.

0 Sepeedah Zadeh over 6 years ago in reply to Ritaban Chowdhury

TI__Intellectual 2850 points

Thanks for the explanation. I would still recommend looking into our Advance light control parts since they have more accessible trigger options.

Best,
Sepeedah

0 Ritaban Chowdhury over 6 years ago in reply to Sepeedah Zadeh

Prodigy 120 points

Thanks Speedah. We will try that.
Ritaban.

0 Ritaban Chowdhury over 6 years ago in reply to Sepeedah Zadeh

Prodigy 120 points

Can I achieve this task with current one?

0 Sepeedah Zadeh over 6 years ago in reply to Ritaban Chowdhury

TI__Intellectual 2850 points

Ritaban,

Please let me take a step back and make a clarification on the 4710G2-EVM.

There is not a default trigger_in option available on the display chipsets including DLP4710. On the 4710G2-EVM, the available trigger to sync with a camera, is the trigger_out signals which are accessible as mentioned in the post that I referenced in my first response.

With that being said, the trigger_in pins noted in the 4710G2-EVM go to the MSP430 and may not be doing what you are looking to achieve. In order to understand their function, you will need to look into the MSP430 code and make necessary adjustments. The MSP430 is only capable of sending I2C commands to the DLPC3439 controller and drive proj_on high. Therefore, you need to see if you will be able to achieve what you are looking for with the I2C commands availabe and modify the MSP430 code if needed accordingly.

As a final note I would also like to mention that the display chipsets are not pixel accurate. Moreover for 3D scanner applications, many of our customers need to use binary patterns. Note that if you need binary patterns, they are not supported on this platform.

Best,
Sepeedah

0 Ritaban Chowdhury over 6 years ago in reply to Sepeedah Zadeh

Prodigy 120 points

Thanks again.

0 Ritaban Chowdhury over 6 years ago in reply to Sepeedah Zadeh

Prodigy 120 points

I downloaded code composer studio. Do you know how to access MSP430 chip on the board?

0 Sepeedah Zadeh over 6 years ago in reply to Ritaban Chowdhury

TI__Intellectual 2850 points

Ritaban,
Please review this post from previous users as it answers your question:
e2e.ti.com/.../2159647

Also note that the MSP430 code is available on the EVM page if you just need to take a look at the code.

Best,
Sepeedah

0 Ritaban Chowdhury over 6 years ago in reply to Sepeedah Zadeh

Prodigy 120 points

This says how to bypass using code composer studio and use cypress chip for on/off. I need to access msp430 to feed my input from camera.

0 Sepeedah Zadeh over 6 years ago in reply to Ritaban Chowdhury

TI__Intellectual 2850 points

Ritaban,

I think I misinterpreted your question. Please take a look at the EVM schematic found in this page:

If your purpose is to get access to those pins, they are accessible through J48 connector based on this schematic. However I will advise again that the DLP4710 chipset does not have a standard trigger in option. Therefore, you need to understand how the MSP430 is using those signals and if it will serve the purpose you are looking for.

0 Ritaban Chowdhury over 6 years ago in reply to Sepeedah Zadeh

Prodigy 120 points

We are buying the projector you suggested to make it easier. But I want to dig a little bit more to see what can be done here. Thanks a lot for the advice.

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DLP4710: Trigger Sequence of patterns from camera