There is this Nextion display , then there are so many TFTLCD displays with 16 or 8 bit data width or SPI etc. In all these cases, there is one common issue when the display is brought from Amazon : lack of proper support for Library and widgets if any.
I am looking for a 7 inch display for an application to show plots and gauges. Touch functionality is not all that essential. Will be using a Mega 2560 board.
Anything that can fit my requirement ( with good documentation ?) even if its a bit pricey thats OK!
would agree with @J-M-L that the Mega has insufficient power and memory to support the type of application which would typically use a 7inch TFT
@noobmastha suggested a Waveshare ESP32-S3-Touch-LCD-7 - I don't have that specific TFT but in the past have found Waveshare support very good and the ESP32-S3-Touch-LCD-7 Wiki provides good documentation and a link to test programs
A 7” Cheap Yellow Display and LVGL will do what you want but might be lacking in I/O. A Mega really isn't a good choice for running a complex display. The Giga would be a better choice.
TBH, in this situation I'd be considering an arduino Q or Raspberry pi and HTML.
@Ardubit I recently bought this Waveshare bundle and I am really impressed with what it can do. I am using Arduino + LVGL + Squareline studio trial version and getting some nice results, I have gauges, dials, sliders, buttons and other widgets communicating with the ESP32 and controlling the gpio and I have only been using it a little over a week.
I actually bought mine from Amazon because I didn't want the wait and thought it less risk of package damage, the total cost was $107 before taxes. If the microcontroller and display suit your purpose that's a really good deal.
Yes I use the Arduino environment for programming and Squareline studio trial + LVGL to create the GUI, Squareline contains examples to give you a quick start.
The Waveshare wiki page has a link to a .zip file with demos and libraries for both Arduino and ESP-IDF, the libraries are "lvgl", "GFX_Library_for_Arduino" and "displays".
This all virtually ran out of the box, the only issue that stumped me for a while was rotation from portrait to lanscape and simultainiously adjusting the touch to match but I have a fix for that now, the touch is spot on and requires no calibration.
I feel your pain with those displays from Amazon. I've had my fair share of struggles with getting them up and running.
For a 7-inch display with plotting and gauges on a Mega 2560, I'd recommend checking out the ILI9341-based displays. They're pretty popular and have excellent support in the Arduino ecosystem, including libraries and examples. One option is the 7-inch TFT LCD display from Adafruit, which has good documentation and a robust community behind it. It's not the cheapest option, but it's definitely worth considering given your requirements.
Actually I am a regular user of Nextion and I use it without the ITEAD library. SO easy. But I actally want to show some gauges and plots and that is where the problem. It has a very limited widgets library and if you want to show a gauge , its too much of work . I in fact use it for standard user interface like below very often… only top half of the 10” display shown as i could not take a full screenshot !!
