ESP32 Forum

Hello guys,

i want to build a little HMI for myself with an ESP32-S3.
I do this just for learning purposes and because its fun tinkering around.

I´ve searched the internet for the right Touchscreen display module which i can use for prototyping but there are so many of them.
Does anyone have a module in use which they can reccomend me?
Since my fingers are quite big, a size of at least 7 inches would be great.

It shouldnt have an ESP32 already on board like many of the china ones have. I wanna use the Dev-Kit for the ESP-S3.
Or do they need an onboard chip for the UART communication?

And whats up with the sd-card slots? Are they needed to store the graphical data for the HMI?

Also, do you have any recommendations regarding software? I mean like drawing the interface like graphs and keypads and mapping all the variables to it.

thanks in advance

Or do they need an onboard chip for the UART communication?

Not necessarily. You can use the S3's built-in USB Serial/JTAG controller for connection to PC for flashing and serial IO.

And whats up with the sd-card slots? Are they needed to store the graphical data for the HMI?

Not necessarily You probably won't need any external storage to build a compelling GUI. SD may come in handy if you want to use images or animations/video clips, but generally the HMI should be fine without.

Also, do you have any recommendations regarding software?

LVGL seems to be what people use today. For that, there's also Squareline Studio available which you can use to design GUIs on the PC and generate C code to create and run that GUI on the chip.

Not necessarily. You can use the S3's built-in USB Serial/JTAG controller for connection to PC for flashing and serial IO.

I want to connect the Touchscreen and LCD with SPI, I2C or that I80 thing. So the ESP-S3 runs FreeRTOS and manages the connections via RS485 and Ethernet and simultaniosly sends the UserInterface to the screen aswell as managing the input from the touchscreen (i believe in and out of the screen is via 4wire SPI).

The screen which i think should be sufficient is:
https://www.buydisplay.com/spi-7-inch-t ... reen-panel

one of these chips is on the board of the screen(which i wanna keep): RA8876 or LT7683
it has a font chip aswell but i have no idea if thats any useful.

LVGL seems to be what people use today. For that, there's also Squareline Studio available which you can use to design GUIs on the PC and generate C code to create and run that GUI on the chip.

So these programms generate c-code which is then compatible with all screens as long as i use an arduino or esp32?

7" is a pretty big display, and 1024x600 is a whole lot of pixels to manage with the limited amount of RAM of an ESP and a whole lot of data to push over a serial interface (1.2MB @ 16 bit for a full-screen refresh, or about 0.5 seconds @ 20MHz SPI clock).

So these programms generate c-code which is then compatible with all screens as long as i use an arduino or esp32?

Yes. The C code uses the GUI API of LVGL (platform & display agnostic), IIRC the GUI components render into an in-RAM framebuffer, and then there are different display drivers to choose from which manage the communication with the actual display.