Does LvGL suite for: ARM Cortex M4, 256K, only dedicated keypad


Atmel SAM53n20a (256k RAM), SPI based TFT LCD Driver

What do you want to achieve?

Evaluate whether the LvGL suites my hardware and application.

What have you tried so far?

Read doc and some source code.

I want to get suggestions from you that whether LvGL suites my hardware and application. The process is an ARM Cortex M4 with 256K RAM, the display is a SPI based TFT LCD driver, color is 16bits. The more special part is the Keypad, it is just a six-button keypad with some functioning meanings labeled on them, for example RETURN, UP, DOWN, SETUP. There is no touchpad, no mouse, no QWERTY.

Is this hardware good to use LvGL?

On the application side, my application is relatively simple. It should show some basic device status info on the left panel of the screen, and some important measuring data in the middle panel. The status info and the measuring data should be refreshed every second. When user pressed SETUP key, a setup screen should replace the middle panel and show a much, user then use UP/DOWN key to scroll the menu and use RETURN key to enter a detail setup screen in which it again use UP/DOWN key to change inc/dec a digital config number (such as target temperature number).

After read some samples of LvGL, some thing looks not obvious to me:

  • It looks like in LvGL, I need a widget to receive keys, but as you see, what I need is like: when anytime you press a SETUP key, a setup window should display or pops up.
  • I see there is slide bar, but what I need is just a digital edit box which can be changed by two keys (UP/DOWN) – Is that easy to create or customize my own widget like this?

If with this kind of programming task, what will you do with LvGL?

It will be highly appreciated if you can give you suggestions and thoughts! Thanks in advance!


Hi woody,

All seems doable.

LittlevGL has a strong support to use the UI without mouse or touchpad. Take a look at this demo get some impression.
To set values you might need a Spinbox object. It also work with keys.

Probably you need to catch the press of “SETUP” out of LittlevGL and hide/create/delete some objects.

I suggest trying LittlevGL in simulator on PC to see if it really fits well.

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Many thanks!!