Lightcrafter 6500 DMD Blinking

To be a little more specific. Reading the documentation showed that there is a "mirror clocking pulse" where the mirror is released, and then sent to a state corresponding to its memory element. My question is then: how do I change the frequency of these pulses, or even better, communicate to the board when to fire them?

Thank you

Thank you for the response. However, I was under the impression that the lightcrafter 6500 device was different than the lightcrafter that you linked to. Specifically, the manual of the device that I have (TI literature number dlpu028b) explicitly requires the use of a newer gui to control the device, and the manual never mentions "extended pattern sequences". These sequences are also never mentioned in the programming guide (literature number dlpu018b). What documentation, if any, carries over from the lightcrafter to the lightcrafter 6500?

Further, I am able to control the exposure time of my patterns. However, if I make this time quite long and look at 100 us timescales, I still see that every 105 us, the image flickers. Is there a command I can use to set this time or alter some clock?

Hi Anton,

You are correct the previous post was of a different LightCrafter user's guide. 

Please continue using DLPU028B literature; there is not 'extended pattern sequence' concept in this platform. 

To avoid the periodic reset, you can select this option, use 'Video Pattern Mode' , in this mode of operation the controller waits indefinitely for the external video sync. So just select Pattern Exposure = 105us Dark time = 0us, select 1-bit pattern to be displayed from the incoming RGB888 video frame. Send two video frames then stop streaming.

We however highly recommend refreshing the DMD; you cannot keep the DMD in this state forever, the other thing you can do is to apply 50-50 duty cycle whenever you are not using the hardware.  

Regards,
Sanjeev

Sanjeev,

Thank you for your response. I am trying this out now. However, I came accross this sentence in sec 3.6.4: The input video source must be stable and locked and continuously being applied, otherwise the firmware will detect that the source was lost and a solid curtain will be displayed.

This is obviously not the functionality I want, can you comment on how to get around this problem?

Thank you,

Anton

Hi Anton,

Sanjeev is currently on holiday, he will get back to you in a few days. Thanks for your patience!

Thanks,
Trevor

Sanjeev,

I have tried what you suggested, but had no luck thus far. If I stop streaming the video, the solid curtain is displayed.

Furthermore, even in video and video pattern modes, I still see switching at 105 us, or ~9.5 kHz. This is a little disturbing because your previous post would indicate that the mirror clocking pulses are based on the vsync, which is 60 Hz in my case. 

A few questions

(1) Could you post more specific instructions to do what you described?

(2) What is the mirror clocking pulse based on, and is there any way to control it? If the current firmware is insufficient, would it be possible to modify the firmware? Our research lab would consider buying modified firmware that allowed us to control the mirror clocking pulses.

(3) Is there a hardware way to interrupt the MCP? Is there an accessible trace?

Thank you,

Anton

(1) Can you show your settings? Set Pattern Exposure - 105us, Dark time = 0; Select only one 1-bit pattern to be displayed. In this case the DMD refresh once every 16.66ms (matches to VSYNC).

(2) This chipset don't have the option to control directly. Also it is not possible to control by firmware change. Discovery D4100 platform is something you can look for such a low level control. As i mentioned in (1) for the setting you can see one reset per 16.67ms. This can be increased further to 100ms by sending video at 10Hz beyond this it is not possible.

(3) No. There is no hardware access to MCP signal.

Regards,
Sanjeev