Help driving the LQ035NC111 on a Pi Zero W using DPI on GPIO?

Im2nelson4u · Post by **Im2nelson4u** » Thu Oct 19, 2017 10:38 pm

Hi, I have a couple of LQ035NC111 LCD panels from past projects and would love to use them on a Pi zero for a retropie build. I know Kite's SAIO boards use this same LCD but unfortunately I am trying to put this LCD in a 3D printed Landscape shell and not a Gameboy.

Here is the datasheet for the LCD http://www.datasheetspdf.com/PDF/LQ035NC111/705487/1

I plan on using this guide to connect it to the Pi

http://blog.reasonablycorrect.com/raw-dpi-raspberry-pi/
and
https://www.raspberrypi.org/documentati ... /README.md

I was wondering how to power the LEDs on the LCD. If im reading the datasheet correctly, the LCD requires 18.6v to 21v to power. The datasheet also indicated Pin 1 through 4 as

1. LED GND
2. LED GND
3. LED +
4. LED +

do I just need to pick a pair or do I need to apply 18-21v to both pairs?

Has anyone attempted to connect these LCD directly to the GPIO

Any tips would help

Thx

tinkerBOY · Post by **tinkerBOY** » Fri Oct 20, 2017 9:12 am

Yes i've tried it. Check https://www.facebook.com/RetroGamerX/po ... 3185232011

What i did is soldered both pairs together.

Im2nelson4u · Post by **Im2nelson4u** » Fri Oct 20, 2017 4:50 pm

Omg thats awesome! May I ask how to soldered to the ribbon cable? Im planning on getting 54pin Fpc connector 0.5mm and a 60pin fpc breakout pcb to make wiring easier.

Also how many volts did you apply to the lcd and what did you use to boost it from battery?

Lastly is there any guides you followed for wiring the lcd and how difficult was it?

Sorry for so many questions ive only built using composite and hdmi for my builds so far

Thx

tinkerBOY · Post by **tinkerBOY** » Fri Oct 20, 2017 11:12 pm

I just followed the instructions at https://www.raspberrypi.org/documentati ... /README.md

Im just using a temporary variable power supply for now. I set it to 19v.

Im2nelson4u · Post by **Im2nelson4u** » Mon Oct 23, 2017 3:01 am

Hi, sorry to bother you again but I decided soldering straight to the FPC cable would be too difficult.
I tried my hand at Eagle to make a breakout from a 54 pin FPC connector to drive the LCD and was wondering if you could take a look.

I plan on connecting it in 18bit mode and was wondering if this layout is okay. Also any chance you have any more pics of your work? Also would it be possible for you to post your config.txt file to enable DPI mode?
Sorry about the messy wiring, literally just downloaded the program this morning and used youtube tutorials to design this.

Thx again

tinkerBOY · Post by **tinkerBOY** » Wed Oct 25, 2017 1:25 am

Im2nelson4u wrote: ↑
Mon Oct 23, 2017 3:01 am
Hi, sorry to bother you again but I decided soldering straight to the FPC cable would be too difficult.
I tried my hand at Eagle to make a breakout from a 54 pin FPC connector to drive the LCD and was wondering if you could take a look.

I plan on connecting it in 18bit mode and was wondering if this layout is okay. Also any chance you have any more pics of your work? Also would it be possible for you to post your config.txt file to enable DPI mode?
Sorry about the messy wiring, literally just downloaded the program this morning and used youtube tutorials to design this.

Thx again

Honestly, im really still new at using Eagle too.

what i was planning to do is make a 54pin fpc board that i can solder directly to a pi zero.

For the config.txt, i just followed the instructions on those links you posted. You can also copy it from KITE's SAIO wiki.

mattc · Post by **mattc** » Fri Oct 27, 2017 2:43 am

For your backlight circuit, there are loads of driver ic's you can choose from. You could start by taking a look at the adafruit tft-friend design:

https://github.com/adafruit/Adafruit-40-pin-TFT-Friend

Use your data sheet for current selection.

You can get this & the routing for the fpc connector onto quite a compact board with not much effort, here's the placement on mine:

Im2nelson4u · Post by **Im2nelson4u** » Fri Oct 27, 2017 6:08 am

wow that is absolutely amazing, will you be selling these? I literally started using Eagle a couple of days ago using youtube as a guide and dont have any confidence in making my own boards yet lol.

I wish i knew adafruit had their design online for the breakout and LED driver, I ended up buy a tiny DC boost converter that does 2v to 25v lol.

Please let me know you sell your PCB, it would help me alot with my portable retropie project

mattc · Post by **mattc** » Fri Oct 27, 2017 7:13 am

It's literally just a prototype at the moment, it works but has a few niggles.

It's also very niche as it's tailored to a specific screen, has fixed brightness etc.

It's also VERY inspired by the one that kite built some time ago, so wouldn't really feel like it was right to sell.

Help driving the LQ035NC111 on a Pi Zero W using DPI on GPIO?

Help driving the LQ035NC111 on a Pi Zero W using DPI on GPIO?

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Re: Help driving the LQ035NC111 on a Pi Zero W using DPI on GPIO?

Re: Help driving the LQ035NC111 on a Pi Zero W using DPI on GPIO?

Re: Help driving the LQ035NC111 on a Pi Zero W using DPI on GPIO?

Re: Help driving the LQ035NC111 on a Pi Zero W using DPI on GPIO?

Re: Help driving the LQ035NC111 on a Pi Zero W using DPI on GPIO?

Re: Help driving the LQ035NC111 on a Pi Zero W using DPI on GPIO?

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