HDMI controller board for display panel

I was wondering if anyone could direct me to a hdmi controller board that can be used to convert the standard framework laptop display panel (ribbon cable) to hdmi for use as a second portable monitor for the framework laptop itself. Preferably with an open nature (firmware, design, data sheets, schematics ect).

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I’m confused, why don’t you use the HDMI card?

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You can’t be serious. In no way you will be able to find one that actually works with open source everything. You can’t just buy any 40 eDP controller board as they have to be compatible with resolution and specific displays. And it’s not a popular display either.

I think he means the other way around. Getting a second Framework display and getting it to accept an HDMI signal as an input which could be used with a regular Framework as a second monitor. That way you could get a proper dual-display setup with matching screens.

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So I meant what minty_root was getting at. A few other questions come to mind. The ribbon connector on the framework board itself does it only support this exact type of display or is there a way to see if other panels may work with it depending on model.

This maybe?

Oh god no. It’d not as simple as if it has the same connector, you need to make sure the seller specified that it’s compatible with frameworks display.

Is it not a standardized connector? 40-pin DP?

It is but not all controller chips support specific displays.

It would be easier to do a DisplayPort adapter, as that would just pass the eDP signal and the EDID more or less directly, and the host system will drive the panel with the right resolution. There are off the shelf ones like this, but which don’t have the right eDP connector or pinout: Dp Edp 4k 120hz Pd Diy Driver Board For Portable Display Screen - Demo Board Accessories - AliExpress

Our display pinout is:

Pin Signal Description
1 BL_POWER 12-17V backlight power
2 BL_POWER
3 BL_POWER
4 NC
5 GND
6 AUXP
7 AUXN
8 GND
9 EDP_TXP_0
10 EDP_TXN_0
11 GND
12 EDP_TXP_1
13 EDP_TXN_1
14 GND
15 EDP_TXP_2
16 EDP_TXN_3
17 GND
18 EDP_TXP_3
19 EDP_TXN_4
20 GND
21 EDP_HPD hotplug
22 BLK_PWM_LCD Backlight PWM
23 BLK_OFF_N Backlight Enable
24 NC
25 NC
26 3V_EDP 3VS
27 3V_EDP
28 3V_EDP
29 3V_TS 3VS for touchscreen
30 3V_TS
31 USB_DP USB
32 USB_DN
33 TS_EN
34 TS_RST
35 TS_INT_N
36 TS_SDA
37 TS_SCL
38 NC
39 GND
40 GND

And the connector type is IPEX 20879-040E

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I haven’t tested this and it is entirely possible it will destroy your panel if you try, but in theory this board with the 0.5mm pitch cable should “just work”. Nvarcher Dp To Edp 4k 120hz Diy4k Driver Board 4k 2k 1080 Adapter Board For Portable Display - Replacement Parts - AliExpress

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Interesting how the connector supports hotplug. Any reasons for that?

I think it’d be super cool to have a second display that is the same as the primary one (always a little bothered when my monitors don’t match), so I’ve been thinking about this today. In theory if you take

this controller: https://m.aliexpress.com/item/1005003740168811.html?gatewayAdapt=Pc2Msite

and took apart an adapter/dock like this:

couldn’t you (through a cable or direct soldering) connect together the two display ports? That way you can package it all up into a compact external monitor? Also using the USB C power pins couldn’t you possibly get power delivery from the laptop>display or from the charger>dock>laptop+display?

I’m don’t know too much about this subject matter understand if I’m misunderstanding something or just entirely wrong. Just brainstorming.

And one last question, does anyone know how (or where I can learn) to test the controller so that I don’t fry a $180 if I try going down this path? I’m assuming you could use a multimeter and see what kind of power output you’re getting and make sure that’s not outside the LCDs specs.

(Framework won’t let me put more than two links in a post cause I’m a new user, so I’m continuing from above)

Plus using these:

You could make it match the laptop pretty well (you’d need to come up with a stand that houses the controller). Though the cost would be $140+ more to do that.

Incredibly enough, that little DP to eDP board just works:

I picked up a version that comes with a cable (Nvarcher Dp To Edp 4k 120hz Diy4k Driver Board 4k 2k 1080 Adapter Board For Portable Display - Replacement Parts - AliExpress). You need to carefully remove our custom eDP cable and then insert the cable that comes with the adapter board.

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Cool, its even got touch support port on it. Wonder if you could purchase a digitizer layer

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In theory, yes, though I couldn’t find any real documentation around this board to know what that connector interfaces to. It is probably just passing through the pins on the eDP connector that are most commonly used for i2c touchscreens.

Also, in theory, with the right cable, you could use this board to connect a DisplayPort monitor to the eDP output on the Framework Laptop Mainboard.

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Oh! There is an even better version that directly does USB-C with DisplayPort Alt Mode to eDP: Nvarcher Mini 4k Edp Dp Driver Board With Screen To Detect Voltage, Current, Power And Temperature - Demo Board Accessories - AliExpress

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That’s amazing! Good to know if I ever have a spare screen lol

Can someone please create a mod kit that could act as a base / stand and board enclosure if someone were to buy the Framework top cover and bezel and hinges?

e.g.
Base / stand + board enclosure + panel + top cover + bezel + hinges (included in the top cover kit) = portable display.

On a second thought, it may not make financial sense if you add up the cost of all the parts.

The display panel + top cover alone would cost $360 CAD…at that point, you’re already into off-the-shelf portable monitor territory.

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