DLPDLCR2000EVM: + Beaglebone black not working- PuTTy opens to black screen

Hi Erika,

Welcome to TI E2E forums and thanks for your interested in our DLP technology.

We will look into this and get back to you within next few days.

Regards,

Lori 

Hi Lori, 

Thank you. Looking forward to hearing back.

Just to reiterate, my questions are:

- How I can access the host using PuTTy/ fix this issue I'm seeing? How can I get to step 9 and login?

- Can I use a newer image/version of Debian with this EVM?

- I tried installing the windows drivers since this is an older image for the sd card, but when I try to install them I get install failed errors. Using drivers listed at the bottom here: https://beagleboard.org/getting-started#troubleshooting

Hi Erika,

1. I recommend following this FAQ for BBB + DLP2000 EVM setup: https://e2e.ti.com/support/dlp-products-group/dlp/f/dlp-products-forum/621466/faq-dlpdlcr2000evm-quick-start-tutorial 
2. It is recommended to use the version of Debian that specifically mentions implementing the cape overlay for this EVM. If you would like to use a different version of Debian, please follow this FAQ here: https://e2e.ti.com/support/dlp-products-group/dlp/f/dlp-products-forum/663939/faq-dlpdlcr2000evm-bbb-cape-overlay-customization 
3. For beaglebone related issues, we recommend to consult the beagleboard forums. 

Thank you,

Chris

Hi Chis,

Re: the previous discussion

I figured out one part of the problem, and it's that its not clear in the FAQ for BBB + DLP2000 EVM setup that when you are using the 8.9 image: BBB-blank-debian-8.9-lxqt-4gb-armhf-2017-08-01-4gb.img

that after flashing the image will be written to the eMMC flash (counterintuitive to beaglebone documentation), and the micro SD card needs to be fully removed and you don't need to click the user/root button upon boot. 

So now I have the beaglebone booting properly with the 8.9 Debian image - just by plugging in the usb to my PC.

My follow up questions (related to this EVM, not beaglebone) are:

1. Is it possible to both have the projector turn on and stay on after boot AND have the beaglebone HDMI display? I have tried different combinations of when to boot the beaglebone black, attach my EVM, power it on, etc but I can't seem to both get the beaglebone display and EVM projector up at the same time. 

I am able to get the projector on if I:

• Plug in mini HDMI, keyboard, Ethernet, and mouse, connect EVM pins and EVM power, and then usb to PC
• Projector on, No HDMI input

Alternatively I am able to get the beaglebone display if I:

• Plugged in mini HDMI, keyboard, ethernet, and mouse (no EVM) and then usb to PC
• Wait until I see the beaglebone display, and then connect the EVM pins and power to EVM
• HDMI display on, but still projector off

2. User guide mentions that I can adjust the focus of the projector, can you explain how to do this?

Please let me know, and thank you. 

Thanks,

E

Just wanted to add that I am still unable to connect to my device via puTTY

However, related to the EVM, another question I have

3. If I follow the command line instructions here up to step 14 https://e2e.ti.com/support/dlp-products-group/dlp/f/dlp-products-forum/621466/faq-dlpdlcr2000evm-quick-start-tutorial

Will I be able to then restart the device, and connect and power the EVM so the projector turns on, and then have behavior as expected? (see the fish bowl demo?) [Since I am unable to connect via PuTTy, where you would normally be able to have both synronously] 

4. I am interested in sending my own video to the projector following the user guide section "example application" but using my own video file instead. How would you all suggest going about this?

Should it be as simple as this: 

1. The existing desktop is “0”

a. "export DISPLAY=:0"

b. "mplayer <file>" OR "vlc :0 <file>" with my filename instead? 

Hi Erika, 

I will answer your questions in four parts:

1. To ensure proper bootup of BBB, the projector must be powered on before the beaglebone black boots up. This is because the BBB will pull the cape info from the flash on the DLPDLCR2000EVM and configure the pins appropriately. EVM must be powered up for this process to occur. 
2. The EVM has a focus knob on the left side of optical engine that can be pushed back or forth to adjust focus
3. I do not understand the question. The EVM will power on if there is power provided. The BBB can be used to send i2c commands to the EVM. Please see the DLPC2607 software programmer's guide here: https://www.ti.com/lit/ug/dlpu013a/dlpu013a.pdf 
4. I recommend using the python library here: https://github.com/RobertCNelson/boot-scripts/tree/master/device/bone/capes/DLPDLCR2000. We suggest reviewing the code structure and using the examples it to make your own python scripts. 

I hope these adequately answer your questions. Please also note that there is a user's guide for this EVM: https://www.ti.com/lit/ug/dlpu049c/dlpu049c.pdf. 

Thank you,

Chris

Thank you for these responses.

1. Thank you for this information. However, when I power on the projector first, and then boot the beaglebone black, then the projector works but the HDMI display of the beaglebone does not work. How can I get both the beaglebone display and the projector up and running at the same time? I know the EVM is causing this issue because on it's own the beaglebone black works as expected and HDMI display comes up on boot. 

2. Thank you. I will use the knob to adjust, but I would like to know if there is a way to access the value of the focus. Is there any way to see what the focus is set to (once you move the knob?) In the programmers guide, it seems I can get the focus lens position, but I don't see where to get the effective focal length of the system based on the knob position. https://www.ti.com/lit/ug/dlpu013a/dlpu013a.pdf (xCA)

3. Thank you for the programmer's guide. 

4. Great thank you for the python scripts- if I wanted to play a custom video, it seems like this script would be best to edit: https://github.com/RobertCNelson/boot-scripts/blob/master/device/bone/capes/DLPDLCR2000/MplayerTest.py Can you verify this?

5. What is the field of view of this projector (or ranges of field of view)? I looked in here but there is no mention of field of view: TI DLP® Pico System Design: Optical Module Specifications (Rev. B). Does this projector have a throw ratio of 0.3 (“ultra-short”) to 2.0 (“long”)? Is there a way to know what the throw ratio is currently set to?

Thank you for your support so far. 

Kind regards,

E

Hi Erika,

We will need some more time to look into this, I will have a response by early next week. Thank you for your patience. 

Thanks

Chris

Hi Chis,

Thank you for looking into this, I am looking forward to hearing back.

Kind regards,

Erika

Hi Erika,

1. Can you clarify if you are trying to get HDMI output from the BBB while also projecting from the projector ?
2. If you have motor control of the lens, then the SWPG will be applicable in this case. You will need to run your own script to calibrate it to your system.
3. N/A
4. Yes this script would be a good start.
5. The throw ratio is 1.6. it is in the user's guide in 3.1 optical light engine overview: https://www.ti.com/lit/ug/dlpu049c/dlpu049c.pdf. To change this would require purchasing an optical engine with a different throw ratio or modifying the optics yourself.

Thank you,

Chris

Hi Chris,

1. Yes exactly, trying to get HDMI output from the BBB while also projecting from the projector. I can't get both working at the same time. Can you all explain how to do this?

2. Can you elaborate on this? (Point to documentation on this?)

4. Great thank you. 

5. Okay great, 1.6 is good to know. Thank you. 

Thank you,
Erika

Hi Chris,

Okay, thank you. I believe I noticed in old blogs that you can project the BBB HDMI display via the DLP projector. If this capability does still exist, can you please point me to the most recent documentation?

Thanks,

Erika

Hello Erika,

Could you please share link to the blog you are referring? 

regards,

Vivek

Hi Vivek,

Yes, here is the blog post from 2018: https://e2e.ti.com/support/dlp-products-group/dlp/f/dlp-products-forum/745752/linux-dlpdlcr2000evm-how-to-use-dlp-lightcrafter-2000-evm-to-project-beaglebone-desktop

I am interested in using the EVM as a "desktop monitor" for the BBB.

The response from Phillippe points to Section 4.0 of the User Guide, but after looking at that section, I see it does not describe how to do this. Specifically I would like to know:

"The I2C commands needed to configure the EVM for external video display mode. Note that you need to have the EVM installed to the BeagleBone Black as a cape, and the appropriate EVM drivers need to be installed to the Debian distro"

I am using Debian 8.9 as recommended in the quick start guide. 

Thank you! Looking forward to hearing back.

Kind regards,
E

Hi Vivek,

After following a combination of the quick start guide + the serial connect documentation here: https://elinux.org/Beagleboard:Terminal_Shells

I was able to play the fishbowl video in the example. Now I have the BBB desktop projected from the EVM.

(you can ignore the above question)

My next questions are:

1. If I wanted to simply just play my own video file, could I edit the MplayTest script by simply changing the filename to my .mp4 file, and then run:

> export DISPLAY=:0

> cd /opt/scripts/device/bone/capes/DLPDLCR2000/

> python MplayerTest.py

(as before) 

to get it playing on the desktop?

github.com/.../MplayerTest.py

2. If I adjust the focus knob, is there a command can I use to access the current focus value? (assuming I don't have motor control of the lens, and I am just moving it manually. If not I will estimate it based on the focal position manually for each adjustment. 

Thank you. Looking forward to hearing back.

-E

Hi Erika,

This "desktop monitor" is using the BBB in such a way that pixel data is sent from the BBB over the GPIO pins to the EVM. It does not send this pixel data over HDMI. 

Section 3.2 of the user's guide will show how the EVM receives this video data. 

To answer the questions you have following,

1. Yes, this is a good start to playing your own video file. Be sure to review the python code used in MplayerTest.py to be sure you are pointing to the appropriate video file.
2. You will need to design your own motor system to adjust the focus lens if you wish to do so. You can use the DLPC2607 datasheet on information for interfacing with an external motor (section 5 - pin functions): https://www.ti.com/lit/ds/symlink/dlpc2607.pdf. Once you have a motor system set up, you can use the software programmer's guide instructions on motor control (compound command opcode 0xCA) to control some external motor. This command will not tell you the position of the focus lever. 

Thank you

Chris

Hi Chris,

Thank you for both of these responses. 

I just rebooted the BBB and EVM, and went to play the fishbowl example video again using the exact same steps & setup as before, but after the command:

> python MplayerTest.py

I got the error:

"Traceback (most recent call last):
File "MplayerTest.py", line 89, in <module>
main()
File "MplayerTest.py", line 59, in main
datalog = DataLog(LogDir, Test_name)
File "build/bdist.linux-armv7l/egg/dlp_lightcrafter/datalog.py", line 77, in __init__
IOError: [Errno 30] Read-only file system: '0524/tmp_header_Video Play Test__Sat__May_21_2016__22_33_38__.xls'"

Do you all know what is causing this?