LCD with capacitive touch + microcontroller integration ($$$)

Hi everyone,

I need a bit of help (paid) for a project I am trying to develop.
It’s a wireless remote control with touch screen. The biggest problem I’m facing is hooking up an LCD to a micro-controller. I am unable to find libraries, put together the code, wiring. I have found various LCD versions available for buying.

LCD specs:

  • 3.97 (4") or 5" size
  • driver: OTM8009A / ST7701S / ILI9806 or other
  • interface: RGB / SPI / MIPI / MCU etc.
  • capacitive touch screen (panel)
  • CTP driver: GT911 or other

Micro-controller specs:

  • any (atmega / stm32 etc.)

Other specs: Total size of the remote should be around 60x105mm, which is ok with 3.97". Not sure about 5" but I’m opened to the idea.

I can offer more info, just let me know. I also have various datasheets.
Thank you!

Have a great day,
Marius

You could look at Nextion displays. These could make it easier to develop nice looking screens with buttons etc.
and come in larger sizes. Otherwise look at what Adafruit has to offer. Their products are usually supported with comprehensive libraries. Adafruit Industries, Unique & fun DIY electronics and kits
How are you powering this ? These screens with backlight have a considerable power consumption.

6v6gt:
You could look at Nextion displays. These could make it easier to develop nice looking screens with buttons etc.
and come in larger sizes. Otherwise look at what Adafruit has to offer. Their products are usually supported with comprehensive libraries. Adafruit Industries, Unique & fun DIY electronics and kits
How are you powering this ? These screens with backlight have a considerable power consumption.

Hi 6v6gt,

Thank you for the info! I'm afraid I have found nothing that fits my needs. There is no 4" with capacitive touch around. Plus, the best case would be to build my own PCB so the remote is as small as possible.

I will be displaying simple text on a black background. The powering will happen via a rechargeable battery.

Marius

Why capacitive only ?

Anyway, I had a quick look and found some near matches
Important is that you find a library for the lcd screen and for the touch controller chip. It is also nice to have a dimable back light to reduce current consumption.

https://www.ebay.com/itm/New-3-5-Capacitive-Touch-Screen-HMI-I2C-LCD-Display-Module-480x320-for-Arduino/253573549737

6v6gt:
Why capacitive only ?

Anyway, I had a quick look and found some near matches
Important is that you find a library for the lcd screen and for the touch controller chip. It is also nice to have a dimable back light to reduce current consumption.

https://www.ebay.com/itm/New-3-5-Capacitive-Touch-Screen-HMI-I2C-LCD-Display-Module-480x320-for-Arduino/253573549737

Capacitive Touch Screen 4.3" inch 800x480 TFT LCD Display Module w/SSD1963 | eBay

Serial 5"TFT LCD Display Capacitive Touchscreen 800x480 with RA8875,Pin Header | eBay

It’s going to be an end-consumer thing, hence the capacitive choice.
Thank you for the ebay modules, I really appreciate the help. The issue is they are modules, the size is big and they are landscapes. I was planning on going with a bare LCD and build the PCB so the size is as small as possible (same as the LCD) - so the end result will be as slick and slim as possible.

I have attached some informative drawings about what I’m trying to build.

nshifted-remote.png

OK. I see what you are doing. Here is a raw screen which could work for you (subject to getting libraries for the lcd and touch part and designing board)
I just did a search on aliexpress for "lcd touch screen capacitive" . At least there appears to be some information with it.

https://www.aliexpress.com/item/32656520746.html

Maybe it's just me being odd, but it seems strange to use a lovely big LCD and then slap a dirty great cover over half the pixels. Why not just draw the frame on the screen in software and save a manufacturing step. Drawing it would also allow future modifications/tweaks/updates etc.

6v6gt:
OK. I see what you are doing. Here is a raw screen which could work for you (subject to getting libraries for the lcd and touch part and designing board)
I just did a search on aliexpress for "lcd touch screen capacitive" . At least there appears to be some information with it.

MDK43WQV118 WCT 4.3 inch LCD screen 480x272 TFT G+G capacitive touch screen|lcd screen|4.3 inch lcd screencapacitive touch screen - AliExpress

Thank you 6b6gt for taking a look around. I've done a lot of research myself. This is wrong proportions and it's still landscape :frowning:

Best LCDs I found are the portrait 3.97" (4") and maybe 5" (I haven't looked too deep into 5")

arduarn:
Maybe it's just me being odd, but it seems strange to use a lovely big LCD and then slap a dirty great cover over half the pixels. Why not just draw the frame on the screen in software and save a manufacturing step. Drawing it would also allow future modifications/tweaks/updates etc.

Good point. We already have an app, so there is a full screen there. What I am aiming with this remote is going towards the future (touch + haptic), but still retain a little of that oldschool feel, with "buttons" and screen.

I see it's a new trend in the automotive industry. Screen button + haptic

Koenigsegg Jesko steering wheel buttons
https://apex-one-assets.imgix.net/store/3b7112234e2929913112d3f7d1d5439ea3b5581790e3aba575ef6d6e35d3?ixlib=rails-2.1.3&w=1200

Mercedes-Benz AMG GT 4-doors console buttons
https://www.mercedes-benz.co.uk/passengercars/mercedes-benz-cars/models/amg-gt/amg-gt-4-door-coupe/explore/interior/_jcr_content/highlightcontainer/image.MQ6.0.20180719112957.jpeg

Hope it makes sense

Screen orientation is a software thing. As most screens are used in landscape mode, that's what you will see on images, but otherwise it's pure software: you're displaying an image, and it just depends on how you create that image. Just see how your smartphone easily switches between landscape and portrait modes.

Connections for such small displays are also usually on the edge, probably because of space limitations (the short side being too short). Larger displays have it on the short edge, or in the middle even.

wvmarle:
Screen orientation is a software thing. As most screens are used in landscape mode, that's what you will see on images, but otherwise it's pure software: you're displaying an image, and it just depends on how you create that image. Just see how your smartphone easily switches between landscape and portrait modes.

Connections for such small displays are also usually on the edge, probably because of space limitations (the short side being too short). Larger displays have it on the short edge, or in the middle even.

Hi wvmarle, thank you for responding. I am aware of that, I'm an engineer myself after all. However, the landscape has a thicker border at the bottom where the electric parts are, so when you flip it in portrait, the border is on the side, resulting in the LCD not being centered. I don't want to thicken the border on the other side to match, because I aim to make the bezel as slim as possible, especially on the side, where if the width is larger than 60-65mm, it's a bit odd (in case of 4"). Hope it makes sense

Ah, got you. That way.

I've had a quick look myself and indeed it seems no capacitive touch in those small sizes available, and most as "landscape" modules.

wvmarle:
Ah, got you. That way.

I've had a quick look myself and indeed it seems no capacitive touch in those small sizes available, and most as "landscape" modules.

The problem is implementation. I have found more than 10 vendors that sell bare LCDs that also offer capacitive touch panels. But I can't seem to find a way to implement any of them, I'm not skilled enough. Some have 45 pins, some have 50, some 51, different drivers (ILI9806 and ST7701 are the most popular), interfaces, etc.

The only 4" module I found is below. I also found schematics for it and some code, but I got stuck at the touch part. The vendor that sells OTM8009A driver LCD, offers the touch panel with separate connector. This module has touch on the same connector and it's resistive (4 pins). I need capacitive (8 pins). So this module has 51 in total, the vendor offers 51 + 8 (59) - I got lost here..

I don't see a reference to capacitive touch on that site; the stylus on the image is typical for resistive touch.

Those 45-50 pin connectors is where the driver IC is connected to. You then connect your Arduino to the driver IC. That driver IC tends to cost about as much as the display, for small displays maybe even more.

It does appear from the illustration to have an XPT2046 resistive panel controller.
The LCD controller is OTM8009A. The supplied code is for an STM32F (blue pill), however, there are Arduino projects which have used this: [solved] OTM8009A 4.7 inch TFT : a too optimistic buy? - Displays - Arduino Forum

6v6gt:
It does appear from the illustration to have an XPT2046 resistive panel controller.
The LCD controller is OTM8009A. The supplied code is for an STM32F (blue pill), however, there are Arduino projects which have used this: https://forum.arduino.cc/index.php?topic=495044.0

Yes, I found this as well. I got stuck at the capacitive part…

wvmarle:
I don’t see a reference to capacitive touch on that site; the stylus on the image is typical for resistive touch.

Those 45-50 pin connectors is where the driver IC is connected to. You then connect your Arduino to the driver IC. That driver IC tends to cost about as much as the display, for small displays maybe even more.

Exactly, because that module is resistive touch and it uses 4 pins from those 51 (no additional pins)