PIC24EP capacitive display suggestion?

benoitstjean · Posted: Thu Apr 04, 2024 12:26 pm

Hi guys,

Just wondering if anyone has any suggestion for a capacitive touch color display perhaps with SPI that was tested with a PIC24 device? Something along the line of a 480 x 800 resolution that doesn't cost 200$?

Thanks!

Ben

newguy · Joined: 24 Jun 2004 Posts: 1911

Quite some time ago I cobbled together a 320 x 480 TFT display with capacitive touch screen overlay (qty 1000 cost was somewhere in the neighbourhood of $10) to an FTDI EVE touch screen controller and a dsPIC. Forget which PIC, but it had something like 1MB or so of flash.

The finished cost was very low but if I had to do it again, I'd honestly choose a processor with built-in screen driving capability. The issue was that the organization needed the finished product ASAP and it needed to be as cheap as possible.

ASAP = PIC since I'm intimately familiar with them.

The FTDI chip wasn't bad but wasn't great either. Lots of bugs came to the surface as soon as the display started to fill with required graphics and indicators, coupled with the swipe navigation I wrote from scratch. Static displays weren't bad but as soon as you tried to move them about, there were a lot of weird display artifacts that I traced to the FTDI chip.

Honestly, have a look at something like an STM32 to see if there's something a) available, b) capable, and c) in your price point. Ditch the free STM32 Cube IDE compiler and go with IAR if you can afford it.

Jerson · Joined: 31 Jul 2009 Posts: 126 Location: Bombay, India

I wonder if you're trying to implement an HMI type display. If so, using a TFT with capacitive touch will be a lot of work and code space. You can mitigate this by using a HMI display from either Nextion or DWIN or 'Stone Display'. The graphics is stored on the HMI, communciation with the HMI is via TTL levels serial. So, the entire project is easy to implement.

If you need to dynamically change the content of screens, then the HMI way may bring some handicaps with it. For example, drawing on the HMI like you would draw on a TFT canvas may/may not be possible in some HMI displays.

Evaluate your need and verify if the HMI route is usable. The displays is not expensive if you do not mind using asian manufacturers of these HMIs

temtronic · Posted: Fri Apr 05, 2024 6:03 am

OK, 'outside the box' thinking, but could you use a cheap 'tablet' as the HMI section ? My quirky idea is to have the PIC talk to the tablet 'somehow',maybe RFID,WIFI, whatever the tablet has to get to the 'outside' world.
You have custom code in the table to be ONLY your HMI device. Essentially your HMI 'app' is the ONLY program in the tablet.

I saw some micro HMI panels but gee, tablet are bigger screens much better for old dinosaurs like me to see.