SPI TFT touch Screens

[Wp100]

Hi,

Am using the 2.8" ILI9341 SPI tft touch screens, 320x240, but would like something a little bigger ?

There are the 3.5" screens using the ILI9481-88 chips, most as parallel rather than SPI and there does not seem to be any real libraries for SPI mode.

Does anyone know of a readily available display 3.5 or 4" at a reasonable price with decent SPI code examples.

 

[Ian Rogers]

The main trouble is SPI with larger pixel formats... 320x240 is meh! but trying to drive huge screens over SPI becomes treacle..

Many manufactures use onboard buffering when using two / three wire interfacing, so interfaces like 4D and such make it soo much easier.

 

[Nigel Goodwin]

I agree with Ian, the problem is speed - SPI can only run so fast, and as the screens get larger the amount of data required increases accordingly, hence the move to parallel for larger screens.

If you use faster processors, such as the STM32, or ESP8266/32 (rather than the Arduino Uno and similar) you can get the speed to the highest possible, but you're still crippled by the maximum SPI speed.

 

[Wp100]

Hi,

The original projects were using an Arduino Nano but the projects are being updated to tft touch screens using the ESP32 which write to the screen much faster.
That said the data sent to the screen is very slow in that its only updated every 30 seconds or so, and the SPI with Touch uses far less i/os than the parallel mode which is preferable for these projects.

Had seen the Nextion screens 3.5 and 4.3" which would be even better size wise, but the way they work and code looks very complex .... any comments about them ?

 

[Nigel Goodwin]

Hi,

The original projects were using an Arduino Nano but the projects are being updated to tft touch screens using the ESP32 which write to the screen much faster.
That said the data sent to the screen is very slow in that its only updated every 30 seconds or so, and the SPI with Touch uses far less i/os than the parallel mode which is preferable for these projects.

Had seen the Nextion screens 3.5 and 4.3" which would be even better size wise, but the way they work and code looks very complex .... any comments about them ?

I've never used one, but from what I can gather you set up the display using the Nextion GUI software and then just transfer data between your processor and display - if you're wanting a touch screen GUI it looks pretty good.

 

[gophert]

The ESP32 runs about 12x faster clock speed but actual throughput seems to be 15-20x.

I think you'll be pretty happy vs the Nano.