How do you to connect a touchscreen digitizer to the Framework 16 motherboard?

I have a touchscreen that should be compatible with the the Framework 16’s eDP port, but I am unsure as to how to connect the digitizer. Is there a spot on the motherboard that it can be plugged into or would I need some kind of adapter? I am pretty new to laptop hardware so I would appreciate it if anyone could point me in the right direction.

Welcome to the forum.
What touchscreen are you looking to use? Is it i2c or usb for the digitizer? And are you looking to fit the touchscreen into the FWL16 shell?

If you’re looking to fit it into FWL16 shell, and it’s an i2c touchscreen, I’m afraid it will likely be really difficult. To the point of, I think, being effectively not possible for most people. There are i2c and usb touchscreen pins on the motherboard side eDP connector, but laptop motherboard side connectors don’t have a standard pinout. Each manufacturer does whatever is convenient, and a custom cable converts it to a semi-standard pinout on the display end of the cable. Since the FWL16 doesn’t currently have a touchscreen, the pinout on their cable will lack the touchscreen pins on the display end, there would be no place for it. So you’d need a custom cable, which I understand is prohibitively expensive to have made for an individual. And rewiring an existing cable is beyond the skills of most people, each wire is micro coax. So the touchscreen pins are there on the motherboard side, but effectively they are out of reach.

You can find the motherboard pinouts on Framework’s github here github.com/FrameworkComputer/Framework-Laptop-16/blob/main/Mainboard/Mainboard_Interfaces_Schematic_Framework_Laptop_16_7040_Series.pdf

If your touchscreen digitizer is usb and it’s broken out to a seperate connector, which I’ve seen done on some screens at least, then it might be possible. You’d need to find a place to connect it, either stealing an internal usb port or adding a usb hub chip. Perhaps from the webcam’s usb port.

The touchscreen I have is for some kind of Lenovo laptop, I think. I already checked the pinouts for the eDP ports on the display and motherboard, and as far as I can tell they are 99% the same. There is one pin that is unused on the motherboard side that is used for auto-brightness on the display. I would think that the display should work normally but with no auto-brightness? Would the Framework eDP cable work in this case?

There is a separate connector for the digitizer, so would that make it USB? That is the part I am unsure about. My plan is to only use the part of the case that holds the motherboard and 3d print new pieces for the screen and everything else I want to add, So I am not worried about it fitting.

Not sure if I follow. The motherboard side pinout is different from the display side. The display side though could be compatible. There are a number of quasi standard display side pinouts.

If the display side pinout of the cable matches, then it may work. You want to be careful to check that it does indeed match. Using the display’s official datasheet from the display manufacturer ideally. The wrong pinout could kill the motherboard and / or the display.

That’s promising at least. But being separate, I don’t think will tell you if it’s i2c or usb. The number of pins could be a clue. If it’s only 4 then usb should be more likely. But that’s not conclusive, there can be extra unused pins or extra ground pins. And you would still need to determine the exact pinout to connect it. If it’s usb, you also need to determine the voltage. Some internal usb devices are 3.3v instead of the 5v that is found on external usb ports. The webcam is 3.3v. This is normally labeled as “3v3” on pinouts. Then if the touchscreen is 3.3v and if you’re willing to just lose the webcam you could make an adapter board to connect the display’s touchscreen usb to the FWL16’s webcam usb. If you want to keep the webcam, you’ll need to add an usb hub chip to split the port.

Do you have the display model number or the laptop model it’s from? Some pinouts are availible with some searching.

After looking at the pdf I have for the touchscreen again, I realize 2 things:

  1. That second connector is a “BLU Interface Connector” for back-light and LCM interface connection.

  2. The screen I have is model NE156QUM-N64, and the pdf I found is for -N69, so I don’t actually know how different the screen I have is from the informations for the -N69 model.