PIC24EP - Biggest TFT with touch and drivers?

benoitstjean · Posted: Wed Sep 18, 2024 9:07 am

Device: PIC24EP512GP806

Hi all,

Just wondering if some of you have used TFT capacitive touch-displays with PIC24 devices or something similar.... and of course, the library code for it. I'm looking in the 3.3V - 3.5V range. I don't like resistive touch, I like capacitive touch like on smartphones.

I'm currently using a 128x128 TFT non-touch which uses the ST7735 driver and it works well but I find it too small. Ideally, I'd like something like 3.4" / 85mm diagonally. The touch part is not critical but nice to have.

I don't need to display anything fancy or fast like video, I just want to display text and buttons so my guess is that it would probably have an SPI interface?

I know that there are some for Arduino but what I briefly saw had many many pins (although they could mostly be ground pins for solid mounting on the Arduino...).

Thanks!

Ben

dyeatman · Joined: 06 Sep 2003 Posts: 1934 Location: Norman, OK

I have used 18F46K22, 24EP512GU810 and 33FJ256GP710A PICs
with the CCS 4.3 Resistive LCD and the ER-TFTM070 Capacitive 5 and 7 Inch
touch displays. Too slow for full screen graphics but worked fine as a user
interface for menus and text displays etc. Used CCS Drivers and Adafruit CCS_GFX_Library.c
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benoitstjean · Posted: Wed Sep 18, 2024 9:30 am

Oh! And do you have a link for the drivers for the ER-TFTM070?

Actually, is it possible that this has a parallel interface? Therefore requiring many pins?

And what is the link for the CCS one?

Ben

Ttelmah · Joined: 11 Mar 2010 Posts: 19538

For simplicity to drive, look at some of the 'smart' modules. These accept
simple commands to do things like draw text, draw lines etc.. Very much
less work to drive than a simple screen. Something like the
RVT43HLBFNN00 is a 4.3" display with your capacitive touch. There are
libraries for these available for the PIC.
As standard these have a very thin ribbon cable connector, but they do
offer a breakout board for this.
There are many other similar smart displays, even serial driven ones.
Much simpler to drive than directly controlling a LCD, especially once
the number of pixels goes up. I'm using the 7" and 10" versions of these
modules.

dyeatman · Joined: 06 Sep 2003 Posts: 1934 Location: Norman, OK

I use the SPI interface for all of my graphics displays. I got the core graphics
library from simple-circuit.com and tweaked it a bit for my application. You
can find the CCS one on their website.
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benoitstjean · Posted: Wed Sep 18, 2024 9:44 am

@TTelmah: for your RVT43HLBFNN00, do you happen to have a link? I plugged that number exactly as-is in Google and nothing comes-up.

Jerson · Joined: 31 Jul 2009 Posts: 125 Location: Bombay, India

If you are willing to use a UART running anywhere from 9600 to 115200 baud, I suggest you look at HMI displays like the DWIN displays with either capacitive or resistive touch. Their website is www.dwin-global.com Another alternative is to use the Nextion HMI displays or Stone HMI displays.

The difference between these HMI displays and the regular TFT type is that the interface is just a UART. You sketch the screens on a PC using your favourite paint tool, upload the images with the overlying objects which would display values or read touches. Takes a little work initially, but once you're used to doing this, it is easier and lighter on the code space requirements of your microcontroller.

These are Chinese displays and if you need someone who has used them to guide you, I can help.
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benoitstjean · Posted: Wed Sep 18, 2024 10:44 am

Oh thanks really cool, thank you so much. I will definitely have a look. For sure I'm comfortable with UART. Will have a look and if I get to the point of ordering one, I will let you know.

Thanks!

Ben

benoitstjean · Posted: Wed Sep 18, 2024 10:51 am

@Jerson: I guess the problem now is how to buy these from Canada.... I'm looking online for something like the GME0831B but there aren't much results.

Ttelmah · Joined: 11 Mar 2010 Posts: 19538

Go on the Riverdi site. Select their Eve displays, and there are several
similar to this. The last few digits are 'optonns', like mounting type, so
probably peaope just list then on the main part of the number.

Jerson · Joined: 31 Jul 2009 Posts: 125 Location: Bombay, India

benoitstjean · Posted: Thu Sep 19, 2024 6:43 am

Hi Jerson,

I send them an email. I'll wait to see what they respond.

I couldn't find the proper documentation that explains all the commands that can be sent over the UART and how to control it. I did find documentation but it didn't appear to contain much information... or did I miss something?

Ben

Jerson · Joined: 31 Jul 2009 Posts: 125 Location: Bombay, India

You could look at this document for DWIN HMI
https://ecdn6.globalso.com/upload/p/1355/source/2024-09/T5L_DGUSII-Application-Development-Guide-V2.9-0905.pdf

I am not in any way affiliated with DWIN. Just a user of their products
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Jerson Fernandes

benoitstjean · Posted: Fri Sep 20, 2024 5:01 pm

Alrighty! So I ordered the Nextion p/n NX4827P043-011C from Amazon:

https://www.amazon.ca/dp/B0B9GT6L8K?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

Not cheap (92$ CAD + a 10$ discount) but for the time it saves, that's nothing. Their GUI software seems pretty straight forward. I tried it a bit today.

Thanks all for your input!

Ben

Ttelmah · Joined: 11 Mar 2010 Posts: 19538

Just one possible caveat here.
Is this for a 'one off', or something you intend to carry on making more?.
If the latter, I think the Nextion displays are EOL.