Selecting a LCD for a Commercial Project

[peter.ing]

I am interested in designing a product that has an LCD built into it. Up until now I have worked with the HMI type LCD's that you interface to by Serial with commands and now I am looking at actual LCD interface to make use of ST's GUI featureset (https://www.st.com/content/st_com/en/stm32-graphic-user-interface.html)

With this in mind can anyone give any pointers the LCD interfaces and where to actually source these LCD's from. When I google there are lots of different options including ones from China I am looking for advice on the best value for money and reliable supply.

My application is to have a touch screen no bigger than a 5inch phone that will allow the user to operate the device interactively.

[Mon2]

Can share some info based on the past 4+ weeks of research.

1) Review which GUI tool you will use with this target LCD display. Specifically note the display controller onboard the display itself.

2) Then confirm that the GUI tool supports the target display controller. Some of the displays used by ST kits are EOL so stock may be limited at best.

3) High resolution displays are often DSI interface based so your CPU should offer this support else you will have to use rather costly HDMI to DSI bridge controllers rather than use the CPU natively. A capacitive touch (CTP) panel is better in response but is a higher cost than RTP (resistive touch panel).

4) From our understanding, DSI interface shares a common register set across other DSI based displays. The values to be stuffed into the register may be different from display to display but the register address and function is supposed to be the same.

5) After the above is known, shop around on Alibaba or Global Sources and watch your email box fill up overnight. We have done this already for our 2.4" TFT display with RTP - our initial project has to be low cost and is consumer target based. For use we are pairing with the STM32F429ZIT6 CPU - the same as applied on the STM32F429i-DISC1 kit & TouchGFX. We can prototype with the real ST target while our PCB is being designed. The target display controller is the IL9341v (same as onboard the ST kit). Not so lucky with the 480x800 display (believe that is the resolution) with DSI interface on another kit. That ST kit is based on the Orient Display controller that is no longer in production. Watch out for such pitfalls.

From other developers, you may find that another GUI tool is better suited for you if the display controller is different on the display you end up sourcing. For us, we are comfortable with TouchGFX and the price is right - it is FREE from ST and is full blown edition. The small pitfalls at this time are that TouchGFX will only work with IAR, SW4STM32 - Atollic and Keil do not integrate well for now.

Search this forum for a document we have posted on using the STM32F429i-DISC1 kit with IAR and/or SW4STM32 compilers. The use of CubeMX + TouchGFX are an amazing combination of tools where you can prototype in minutes rather than weeks if doing the same from scratch.

Hope this helps.