How do you connect BeagleBone black to a LCD screen with a 40-pin TFT Friend?

Question

I am a student in computer science and I am currently working on a project to create a gameboy from scratch with only a Beaglebone Black REV C, a 40 pin TFT-friend that I bought here, and a 5'' TFT screen bought on buydisplay.com/default/5-tft-lcd-display-module-wvga-800x480-high-resolution-for-mp4-gps. Because of the small amount of information available, we probably did something wrong and our beaglebone black short circuited and refuses to turn on. We bought a new one and are looking to prevent that from happening.

Which pins of the beaglebone black are connected to which of the TFT friend? You can see our current TFT pinout on 
Before our beaglebone black fried itself and refused to turn on, when we turned it on, the screen lighted up and you could see a white background and the backlight turned on.
How do we display pixels or images on the screen? As the description of the TFT says: "There are no tutorials on how to use this TFT-friend", we do not know if we need to write our own driver for this screen or if there's drivers out there ready to use with this TFT-friend?
Are we missing a hardware piece? Our teacher wants us to use only these 3 elements mentioned in the first paragraph, but are we perhaps missing one important element that might help us display images on the screen?

Can someone help us?

user785968 · Answer

Just my input but I do believe that the beagle bone black is only rated to draw 3.3v out of its gpio no more or you will fry part of the processor. This may be why you killed your first board... I would recommend using an external source to power 5vin pin.

Answered by user785968 on December 23, 2021

Cem.S · Answer

I was passing by when I read your post.
I did exactly what you are trying to do not so long ago. It's actually quite simple ... if the pinout of the LCD screen is identical to the one of the TFT friend ! You have to wire the LCD signals of the BeagleBone to your TFT friend (the signal names are similar). You will notice that all RGB signals are not wired but it is normal.
Additionnally, the TFT friend requires its own signals : a clean 5V input, a 3.3V input, a PWM to handle brightness...
My advice, pick those voltages from your BeagleBone only if it is powered with a solid power supply (> 2 A). Otherwise, at least in my case, the voltages may be too weak to power the LCD if you did not wire the backlight signals. 
Plug the PWM to a 3.3V signal, as well as the ON/OFF.

On the software side, ensure that the LCD controller of the CPU is activated and clocked. I suggest you to try with the very good BSP provided by David Vescovi here : https://beaglebonebsp.codeplex.com/ . The LCD screen is activated by default.

I also fried one of my BBB while trying to make an LCD screen work. Never understood how it happened and never succeeded in making the screen work. I cannot check the LCD screen that you picked as the link is broken. But, FYI, I am using a newhaven display now and it works perfectly (http://www.newhavendisplay.com/nhd50800480tfatxlctp-p-6062.html).

I hope that this could be useful to you !

How do you connect BeagleBone black to a LCD screen with a 40-pin TFT Friend?

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