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LCD screen reverse engineering - Help Answered

Trying to get help on reverse engineering an LCD display to work with a project I am currently working on. I'm trying to use a Nintendo switch display and they for some reason have (I think) 26 or 30 pins, which is annoying because tablet screens work on 24 pin usually. It also appears that there are no pinout diagrams at all for the screen so it's not ideal. This topic is also open to other suggestions as alternatives so go ahead and suggest away.

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Downunder35m
Downunder35m

12 months ago

I can only give you the same advise I collected over the years:
It simply is not worth the hassle to mess with a display unless you already know or have a suitable controller for it.

With very few exceptions these displays are all custom solutions.
With that comes the fact that it is often extremely hard to find usefull hardware info, even worse for finding a usable controller to make the display what you need.
There are evaluation controllers available that support a huge amount of possible connector layouts and driving protocols.
Used for large scale testing in a factory and with the corresponding price tag.
Back in the old days of LCD based displays you could reverse engeneer them by probing them to find the pins for the rows and columns, time consumin to the max but it worked for most displays.
Today though most display comes with a two stage controller system for performance reasons.
Means the actual display controller no longer provides the data for the pixels itself but instead uses a bus system to address blocks or entire rows.
At the end of these ribbon cables you now often find thin blocks - they are not the connector to the glass, they are actully microchips.
Sadly you would need to know how to address them, how to prvide the digital data AND how to provide the correct timing for all so they work.

Have a look at the usual supply stores for Arduino and Raspberry PI products.
You can get a quite good display with full touch function at moderate prices now.
There might also the alternative to misuse a portable DVD player as without the drive the electronics don't take much room.
You would need one with a video input option though, most have it anyway.
Just add a suitable sized touch foil on top and you are set to go.

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lordwindysquirrel
lordwindysquirrel

Reply 12 months ago

Thanks, i appreciate it as a new user, and for the alternatives

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Orngrimm
Orngrimm

12 months ago

You checked https://github.com/dekuNukem/Nintendo_Switch_Reverse_Engineering ? There (@ Touchscreen controller) he notes that techinsights tells us it is a custom part by STMicroelectronics for the Nintendo Switch.
He even links to a I2C-dump for the bootup of the screen @ https://github.com/dekuNukem/Nintendo_Switch_Rever...
Thats already a lot. But what happens on the other lines? well... Time to buy a Logic Pro 16 Pro for around 1k$ and probe those lines in 2 segments.
Will it be easy? Hell no...

Honestly, if i read your post, i think you just want a nice OLED-Display or TFT-Display to use in a project... Why not buy a proper one with a known protocoll and propably even Converter-boards and proper documentation? Price propably... But a Switch-display at no cost is not free. You still will need to invest a HUGE amount of time (not free) and also propably have to up your game in terms of equipment (Surely not free). So in my book i would value my propably 2 weeks of crunching and reverse-engineering at a higher cost than reasonable TFT on a demoboard of an STM32 like the STM32F469I-DISCO boards (Around 60$ at mouser.com)... Also would have a good load of Softwaretools and democode already over at ST: https://www.st.com/en/evaluation-tools/32f469idisc...

But of course, you can also choose any other formfactor of the discovery-boards they have. A nice overview can be found (but not only) at https://doc.embedded-wizard.de/getting-started-stm...

Also ,maybe worth a look are the different post over at https://forum.arduino.cc/index.php?topic=488605.15
May give you some pointers...

I personally used those OLED-Displays (Like 2 inches in size, dirt cheap on Aliexpress) with great success in different projects at work...

But you have to be aware of a simple fact: The m,ore pixel you want to push, the more memory and the more CPU-Power you will need. Thats why normally Microcontroller dont go a lot over 800x600 or the like... So if you want to push a lot of pixels, be sure you have a VERY decent external memory attached with a highspeed-bus... We can normally say byebye to stuff like Arduino and STM32 for HD720 or fullHD...

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lordwindysquirrel
lordwindysquirrel

Reply 12 months ago

You're right about the price side of it because a 7" lcd screen for the pi of the same resolution is around £100, but there are other reasons that are not worth going into because of the inevitable difficult in setting it up, so you know I was trying to see if there were any people that had maybe stumbled across a way of interfacing with non-generic displays. thank for your time as well, there are some good links there.