I am thinking of starting a project with very low computational burden - mostly just using a UI to change when and how outputs will change over long periods of time. I was planning on having the UI be touch but I could also use soft keys off the edge possibly.
I haven't decided on a size specifically yet but probably something 3.5" or above is a good place to start. Pixel resolution should probably be 320x240 or above as well.
So, what's the best Arduino + TFT combo that could get me to a "decently fast" refresh rate?
And to qualify that question a bit - I'm hoping screen redraw, if noticeable, is at least fast enough to not be a burden. Maybe I'm looking for about 1/5 ~ 1/2 second to clear the screen and draw some text and shapes on top. Something that actually operates in units of >1Hz is preferable though - is something like that feasible with Arduino?
My last constraint is cost. Looking to do this under about $40 if at all possible.
Bottlenecks in the past for me have been with SPI tfts and the generally slow clock speed of Arduinos, at least when you compare them to modern CPUs (which is a bit unfair, I'll grant). I haven't tested a parallel tft but that is definitely an option - I just need confirmation that it can achieve the kind of refresh rate I was hoping for or if there is some other technology that can instead.
Let me know if you have any ideas! Or "near misses" will help me understand the general limitations I'll be running up against too.