I am looking at starting a project with the BeaglePlay, and I want to connect a 7" touchscreen to the 40 pin FPC connector. From the schematic, I see that the connector is exposing the OLDI LVDS for the AM625, along with I2C2, backlight, power/ground, and TP_INT_1_8, which I assume is a touch panel interrupt.
My issue is that I have been looking all day for a compatible display panel with touch panel and I have come up empty. Does this pinout have a name I can be googling (OLDI 40 pin and LVDS 40 pin don’t work), or can anyone show me an example of a compatible device? Not looking for a product recommendation, I just want to know if these exist.
Lincoln Tech Solutions made a custom display. Unfortunately, for OLDI we didn’t find any off-the-shelf options. They should be making that display available for purchase. We’ll be using them for demos at Embedded World.
I also have been looking for OLDI displays as well for BeaglePlay as it would be an ideal candidate for a new application for a future design for the company I work for.
I’d love it if maybe the designers of BeaglePlay could chime in on what kind of options exist today for touch-screen LCD panels using their OLDI interface.
You can connect any LCD which supports dual-channel open-LDI. Some LCDs may require higher voltages for backlight etc. hence individual adaptions are needed for that (ie DC/DC step-up converter).
I was able to connect an industrial chinese LCD to the Beagle. You’ll need to recompile the panel-simple.c driver with matched settings for your LCD. And of course, load the correspondig overlay at boot.
Both displays are the same and feature touch, the difference is LCD185 has very little bezzle while LCD217 has an overmolded bezzle that looks like a Tablet and IMO is easier to mount.
Puh! Lincoln LCDs seem quite expensive. And pinout from links above doesn’t fit to Beagle’s FPC connector either.
Better purchase some 40 pin FPC/FFC pitch adapters on ebay and connect any LCD you want. Keep wires short w/ twisted pairs and try to create some GND screen around.
The pinout does actually match, they just come with an adapter that adapts it to the TI EVM so that’s where the confusion might be. I have them working at my desk and we designed them along with Lincoln specifically to work with play.
Those adapters are fun, what display did you hard wire yourself? Do you have a part# & datasheet?
It’s a customized 1280x1080 LCD w/ touch derived from a car center stack. Was able to fiddle out the LVDS pairs and match them to the Beagle.
I noticed, bringing the touch interface to work is much harder without spec. But often, manufacturers are using same touch protocol across their several products. In this case it’s a Himax LCD+Touch controller IC for what I have found some similar Linux driver code in Github to be modified a bit…
Thanks for this guidance. I purchased a single-channel LVDS display, and tried it without success, then, I purchased the LCD217, and think I have wired it properly.
When I run the various debian/ubuntu images, the HDMI screen works, but I cannot find an image that drives the LCD. ( When the LCD is attached, the x-windows does not come up on the HDMI screen, so, there seems to be some recognition, or interference. )
Do you have a recommended image for running the LCD?
I got my LincolnTech LCD working, and it works happily with an HDMI display.
I added an overlays directory to /boot/firmware [ mmcblk1p1 ] and put k3-am625-beagleplay-lincolntech-lcd185-panel.dtbo into the directory (from /boot/dtbs/ti [ mmcblk1p3 ] ).
