8-bit parallel touch screen lcd

[ep.hobbyiest]

Hi,

i am looking for 8-bit parallel touch screen lcd and 4-5 inch big. I ll be using stm32, chibi os. So, please suggest me some lcd which can give good effect on ugfx stack.

[Joel Bodenmann]

There are plenty to choose from, of course. However, one of my personal favorites is this one. The same module is available with lower resolutions and other configuration options. I could link a dozen more display modules like that but at the end it also depends on factors like how many you need (eg. is this a hobby project?), whether price is an issue, whether it's used in daylight or not and so on.

Another display driver that is very well supported by µGFX is the SSD1963. The same manufacturer/supplier from my first link also has display modules with that display controller.

One very important thing I'd like to tell you is that you definitely must connect that display controller via the FSMC peripheral to your microcontroller. Otherwise you have to bit-bang the interface which is a HUGE performance drop both in terms of frame rate and CPU.
I would furthermore also recommend you to rethink whether you really want to go with an 8-bit parallel interface. Almost certainly you will be using an RGB565 color format which means that every pixel is two bytes large. This means for every pixel you have to push 16-bits. When using an 8-bit parallel interface this means that you have to perform two write cycles for just one pixel. Due to timing constrains such as bus setup times, hold times and so on you are not only two times faster with a 16-bit interface but actually more than two times.

My personal recommendation:

• RA8875 or SSD1963 display controller
• 16-Bit parallel interface connected to F(S)MC of STM32
• Capacitive touchscreen if you can afford it

[ep.hobbyiest]

Thanks for suggestion.

i thought of using 16-bit only, but to save some pins i was thinking. but thanks for changing my mind again.

I am looking for resistive touch and bit cheaper option. I ll be using it to show temperature of oven using widgets and to adjust it using touch screen.

 

 

[Joel Bodenmann]

Yep, I can only repeat my recommendation to use 16-bits instead
Can you tell us roughly what size (in inches) you'd like to use?

[ep.hobbyiest]

I think 3.2 inch or bit larger is sufficient for me. I ll be using stm32f controller. 

 

[Joel Bodenmann]

These are known to work exceptionally well: eBay SSD1289 3.2" TFT module. There are a couple of different variations from dozens of different suppliers. The important thing is that you pick a module that uses the SSD1289 display controller, a 16-bit parallel interface and has touch.