I have been doing a bit of research in to this and I am super doubtful this is possible, primarily because there are no existing adapter boards that do this… and if it were possible you would expect there to be. What is super frustrating is how many LVDS/HMDI/DP to eDP adapter type boards there are, but this seems to be missing.
I would basically like to attempt to drive an LCD that is 2 lane 30pin eDP from the motherboard. Now that you can get the cable from Framework connecting a third party 40-pin display should be relatively trivial (so long as it adheres to the standards).
From the pinouts on the 30/2 and 40/4 eDP connectors it looks like you should be able to just wire up the 30pin to the correct lanes in the 40 pin - but I can find no reference of anyone doing so online.
So I’m just making this topic to see if anyone here who is a little more familiar with the standards can weigh in as to why this isn’t possible, or if there are any other solutions (short of using a separate driver board - which is my current solution, but it dumps unwanted heat into the enclosure I’m making and takes up far too much space)
Edit: Also, if anyone has the datasheet for the 13" Framework panel (NE135FBM-N41.pdf) I would love to have a look, it’s a paid download on Panelook which is a shame.
edit: So… short of the knowledge as to why this probably wont work I went ahead and designed an adapter on EasyEDA and ordered some boards. I have a couple of ‘spare’ displays from this ongoing project so if I fry one it’s not going to be the end of the world.
I fully expect someone is going to come in and tell me that I just wasted the time/money/effort in doing so, but what can I say… I’m inpatient
Ive been poking through similar topics myself as well, the biggest issue with using a premade 40 pin to 30 pin adapters is that apparently, there are two different 40 pin edp connectors, one for high res screens (what framework uses) and one for touch screen enabled screens. Apparently from what I’ve read, the two arent pin compatible
it really blows my mind how loosey goosey a lot of EE “standards” are
Yea I had read that… However the info I had read was that Framework were actually using the video+touch pinout, but that they just didn’t connect the touch.
But either way the total guess that I’m going on here is that both types of 40-pin have the relevant pin outs for a 1080 screen, so by connecting those and just leaving the ‘extra’ ones unconnected maybe it will work…
Who knows. I have my main board now and my adapter board from jlcpcb should be here in a few days. So we will find out if I kill a screen. I don’t even want to think about killing the main board
So I was pretty sure this didn’t work. I got my adapter board a while back and plugged it in and no dice… the ribbon cable got warm suggesting something was up and I unplugged. Fortunately nothing damaged.
I then took another look and realised I had routed one of the GND pins to the ‘wrong’ GND (as labelled) on the monitor… so I ordered a new board with this ‘fixed’ and tried again… but still no dice, the exact same problem.
I was about ready to give up, but figured I best stare at the PCB again and double check everything. I went through it, carefully checking the pins went to the right place, which they looked like they did… as a last ditch I thought I would double check the ‘pin 1’ of the monitor connector corresponded to the schematic I was using and what would you know it wasn’t… I had literally been wiring the whole thing up ‘back to front’ - pin 1 into pin 30 and vice versa.
So I fixed that and ordered a new board. It came this morning, plugged in and worked!
I’ll share the EasyEDA files when I have a second, but this will not work for all 30-pin displays, only those with the same pin configuration as the one I’m using.
Not sure if they ever managed to get the touchscreen detached however.
Edit: Actually missed that they seemed to be mistaken - that spin 713 screen is the exact same screen but with a touch overlay… not OLED.
Sooo… maybe I am also the first third party screen. Although any BOE 40-pin (assuming the same pin layout, and BOE screens seem to reflect the VESA standard) should connect up directly I guess.
You should be able to use that to directly order from JLCPCB by following some basic “how-to” pages on how to get from an EasyEDA design to a JLCPCB order, JLCPCB will do the SMD components for you as well. 5 boards cost $20 delivered to the UK with one of their regular coupons.
You are obviously responsible for your own DIY adventures. If the pins and voltages match up you should be golden, but if you aren’t prepared to eat the cost of a dead board you probably shouldn’t be mucking around with DIY-ing such things.
Yes, once the chipset drivers are installed I can adjust brightness using the Windows slider - I assume this is what the FW Keyboard would control if you were using that, but I can’t test that.
Hey Dylan, thank you for the reply. You are right - I hadn’t checked 2 lane 40 pin vs 4 lane 40pin as u/runoono mentioned. I’ve now checked the pinout of the board you designed - the pinout is the same as the one i want to get. I will likely try to get your board printed and use that as a test.
In the longer run will have to figure out if i can design and print one similar to the item i shared with you as i think a pcb is too thick to put behind the screen
Great, I hope it works for you - in regards to it being too thick - is there anywhere else you can store the ‘adapter’ and/or have you looked at the 0.6mm PCBs from the likes of JLCPCB? They also do ‘flexible PCBs’ which are very thin.
One alternative is to purchase a 30 pin edp cable (non fpc type) and splice it together with the FW 40-pin. Very fiddly though.
