As part of element14’s RoadTest program, I recently got to review Texas Instruments’ DLP LightCrafter Display 2000 pico projector for BeagleBone Black. After finishing the review, I wasn’t satisfied with the performance of the BeagleBone Black, and decided to swap it out in favour of a Raspberry Pi 3B+.
Credits go to Philip Hodgers, whose post I found on TI’s E2E forum, for figuring out the wiring and config parameters to get the projector to work via the Pi’s DPI interface.
Preparation
You’ll need:
- Texas Instruments DLP LightCrafter Display 2000 EVM for BeagleBone Black
- Raspberry Pi with up-to-date software
- 26x F-F and 1x M-F jumper wires
- 6x standoffs and 2 screws
The Raspberry Pi can be prepared using my headless setup procedure: Headless Raspberry Pi Setup with Raspbian Stretch (Pi 3B+ compatible). Make sure I2C is enabled using the raspi-config utility.
Configuration
The following block needs to be appended to /boot/config.txt. This can be done straight from the Raspberry Pi, or while the SD card is mounted on the PC.
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# Add support for software i2c on gpio pins dtoverlay=i2c-gpio,i2c_gpio_sda=23,i2c_gpio_scl=24,i2c_gpio_delay_us=2 # DPI Video Setup dtoverlay=dpi18 overscan_left=0 overscan_right=0 overscan_top=0 overscan_bottom=0 framebuffer_width=854 framebuffer_height=480 enable_dpi_lcd=1 display_default_lcd=1 dpi_group=2 dpi_mode=87 dpi_output_format=458773 hdmi_timings=854 0 14 4 12 480 0 2 3 9 0 0 0 60 0 32000000 3 |
What this does is:
- move the I2C interface to pins not used by the DPI interface
- define the video output format and timing information
Wiring
The wiring is not difficult, but there are quite a lot of connections to make (27 to be exact). It is important to take your time and double check every connection before powering on the Raspberry Pi.
Below, are the pins and their numbering on the EVM (source):
Here’s how they map to the Raspberry Pi’s GPIO:
I’ve added P2_6 (5V) via GPIO pin 2 to power the EVM from the Pi or vice versa. A bridge is then required on the EVM from P2_6 to J3 using the M-F jumper wire. The EVM’s 5V/3A power supply is plenty to power both devices.
The resulting wiring should resemble the pictures below. I’ve used three stacked standoffs to create enough clearance while keeping everything in place.
Video & Audio
After applying power, the EVM will display a default splash screen. Some commands need to be passed via its I2C interface to display the Pi’s desktop.
This can be automated to be executed at every boot, by adding these commands to /etc/rc.local before the “exit 0” command:
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pi@raspberrypi:~ $ sudo nano /etc/rc.local ... sudo i2cset -y 3 0x1b 0x0c 0x00 0x00 0x00 0x13 i sudo i2cset -y 3 0x1b 0x0b 0x00 0x00 0x00 0x00 i exit 0 |
These commands configure the EVM to match the configuration specified earlier in /boot/config.txt, and change the input source.
Finally, the easiest way to get audio running, is probably to use a Bluetooth speaker. It’s easily set up too.
- click on the Bluetooth icon, and select “Add Device …”
- put your speaker in discovery mode, it should appear in the list
- click “Pair”
- once pairing is successful, right-click on the audio icon and select the speaker
That’s it! You should now have audio and video running!
You can connect to the Pi via VNC to start YouTube for example, and start enjoying your favourite content on the biggest screen in the house …
Wow. Brilliant.
I’ve been looking at pico projectors, especially this one, but couldn’t work out how to have DPI and i2c!
You’ve made a remote controlled projector thay can be used for so many art projects. Cool.
Nice work.
I can see shades of Minority Report becoming available shortly.
Mark
Hello,
I have followed your tutorial but unfortunately I can see only the LightCrafter screen and not RPi3 desktop. Did I forget something ?
Thank you for your help!
Strange,
I’ve had reports of others with successful results.
Can you try manually executing the i2cset commands and see what happens?
sudo i2cset -y 3 0x1b 0x0c 0x00 0x00 0x00 0x13 i
sudo i2cset -y 3 0x1b 0x0b 0x00 0x00 0x00 0x00 i
I also tried with this command by changing the display config commands and connected to both hdmi and DLP projector at the same time.
But it shows “Write Failed”
Verify I2C is enabled. You can do this via the “raspi-config” command.
yes i did the same, but nothing changed in DLP2000, it just shows the IT’s default splash screen.
I think in this method we are using the software i2c pins. right?
I followed the instruction but unfortunately I only see the projector keep flashing. I also connected my Pi to my TV via HDMI and after changing the config.txt the HDMI output doesn’t show anything on my TV screen.
If you want HDMI to work, you’ll have to revert the config.txt.
For the projector: use short wires, try to use the same length for all and double check every connection. What kind of power supply are you using?
Thanks a lot for the tutorial and your help! I have modified the config.txt by changing the DPI_default_lcd to 0 and the HDMI output works now. But the DLP2000 still just keep flashing lights.
I did have to use some long wires as I am using breadboard to connect the projector module.
I am using the standard 5V/3A power adapter for pi and powering the projector from the pi by connecting J3 to the pi 5V pin as shown in your instruction.
I just found if I shutdown the pi but still connect it to power, the DLP2000 shows the default splash screen. But as soon as I boot the pi the DLP2000 starts flashing and no splash screen. Maybe there is no enough power passed to the DLP2000 from the Pi? I will buy a power adapter to power the DLP2000 directly and see how it works.
Update: I changed to short wires and everything works perfectly now. Thanks again for the tutorial!
what is the p2_6 is used for? cant you directly put on jumper 3( right pin, further from p2)?
p2_6 is N/A. when lightcraft is powered from raspberry it simply starts flashing. lightcraft was on with 5 v, 1 amp separate connection though.
I am having i2c communication issues from raspberry pi 3( it is not communicating with any device).
however I am able to identify lightcraft with arduino i2c.
i also seem to have damaged one lightcrafter( i had ordered 2 to india)
so long way to go before i make them talk.
You could, no problem to connect straight to J3. P2_6 is N/A on the cape, but as a passthrough, it provides 5V to the cape using the connection to J3, as illustrated. I just kept all my connections from the Pi to the underside of the cape.
I power both the Pi and the LightCrafter from a single 5V/3A PSU.
Make sure the jumper wires you use are short and all of the same length, and everything should work, as multiple users have reported.
can i connect a raspberry pi 1 to the dlp2000 aswell and if so how?
I suppose you could try the same config and pinout with a RPi 1B+ (40 pin header). For this config, the RPi 1B (26 pin header) won’t work.
what about a raspberry pi zero w 1.1. ?
Sanjay prise kitna hay iss product ka,, or kaha se kharida hay,??
oh, failed to mention p2_3( v int reference of 3.3 v was given from arduino) to make it identify. it did not identify till then.
i have no idea why you have not used that pin from raspberry pi as well( 3.3 v referece at p2_3)
Thanx for providing guide. I have a issue regarding the stability of the projection. The screen is shifted to right and files manager does not display properly. Can you please help.
Please check the following things:
– all jumper wires are short and of same length
– all jumper wires are properly connected
– both devices are powered from a single source
Could this also be the problem when colors are not right? The projector works and is connected, but the colors on the screen are off. I used 75mm jumper wires, all from the same pack. They are still joined next to one another, could this cause interferences?
Thanks for the great article!
Do you resolved the issue? I have the same problem, reconnected everything twice…
There’s a PCB available on Tindie: https://www.tindie.com/products/mickmake/pi-projector/
Perhaps this will solve your issues.
Hello Frederick,
I followed your tutorial and everything works great. The only problem is that I have some shaky image when displaying the raspberry pi desktop. It is like a kind of glitch. Do you know what can it be?
Thanks for everything.
I would suggest to check all wires have a proper connection and perhaps that the power supply is powerful enough. Other than that, no real idea, sorry :/
Any alternative of using Short wore of same length ?
There’s a PCB available on Tindie: https://www.tindie.com/products/mickmake/pi-projector/
Thanks for this guide! I got it working great. I’m thinking of getting a HiFiBerry to use for audio. The specs on that show that it would require the use of gpio2 and 3 but those are in use by the projector. Would I be able to relocate these for the projector and if so what part of the code would I change?
Sir your project ia so nice,,Sir you make a video tutorial for this project..
This IS the tutorial, there won’t be any added value in having it in video format.
fredrick,
got it!!! And it is brilliant! I got it on pi-zero as my pi3 i2c pins were not working.
long or short wires may matter about screen flicker at the edge otherwise it really does not.
I did exactly same as you did.
the pi-zero is a nightmare as it has micro-usb. so headless was the only way to go.
very much obliged!
Great news! I’m glad you got it to work!