Hey everyone, I'm new to Arduinos and new to circuits in general, looking to get my feet wet here with just wiring up a generic 2.0 TFT lcd touch screen, figured I'd ask for some guidance. I apologize in advance if this is a lot to unpack between my ignorance on the subject, and by all means if these are common or basic enough questions to refer elsewhere that's likewise appreciated, but figured this would be the place to start asking questions.
The part itself just seems to be somewhat generic and I havent been able to come up with any documentation on it. It has the driver IC and pin headers stamped on it (which is as far as my understanding of this really goes). I've tracked down the appropriate libraries, but between that and the part i have in hand, where do I proceed in both the software and hardware side of things? And once completed, how do I verify this (even just by displaying text on the screen)?
Again, being that this is a first project I apologize in advance for my level of ignorance in what I may need. I have a bread board and jumper wires and a basic understanding of how they work, but beyond that really have no idea what I'm doing.
Thanks!
Sorry, for some reason the forum won't let me attach an image so i can't show y'all quite what I'm working with, but can certainly try to answer any questions in that regard to the best of my abilities.
Also, to the best of my understanding, would I be trying to connect this to digital pins (as opposed to analogue)? I understand the difference in functionality between the two,, but how do I know what the drivers and part pins are referencing? And how do I go about setting this up?
Sorry again for being such new blood, been trying to understand all I've been able through reference, but the practical application is where it begins to escape me. Thanks!
It is an OPEN-SMART screen with a ST7775 controller. (the clue is in the writing on the pcb)
It is similar to the ILI9225 controller which is supported by the Beta version of the MCUFRIEND_kbv library on GitHub.
These displays are 3.3V so you must use a 3.3V Arduino e.g. Due, Zero, ...
If you are determined to use a 5V Arduino like Uno or Mega, you must use thirteen level shifters.
David.
Thanks, yeah, I was able to figure as much from the PCB, im just so new to everything im not sure what else I'm even looking at from here.
And yeah, I did see that it was a 3.3v display, but also suppose I should've mentioned im using an Arduino clone and the data sheet specifies a 3v3 power pin. Is this just it'd own power pin or does this come into play here?
All Arduinos have a 3.3V power pin. But the GPIO pins on a Uno, Mega2560, Leonardo, ... use 5V logic levels.
You will seriously damage your display if you connect it to 5V logic.
It is possible to connect thirteen Level Shifter circuits. I would sooner top myself.
In an ideal world, all 5V devices would disappear down a big hole.
Note that if you had bought a cheap 2.4" Shield, it just plugs in to your Uno. And away you go.
Also note that they will work equally well on a Due, Zero, ...
David.
Ah okay, now I see the difference between the power pins and gpio, my mistake. And yeah, I see what you mean. I will look further into that before proceeding with any more specific questions. I'm also learning circuits at the moment, but understand what you mean for sure, thanks.
And yeah, I also bought a cheap shield, but between the damaged pins when I received it, my inexperience, and my inability to find any working solutions or fixes, that came up a bust as well
But since I'm trying to learn as much as I can at the moment, this is the right footing to figure out what I'm looking at, at least. Thanks!
I bought two ILI9225 displays just like yours.
If you are in Europe, I will mail you one of them. Mine arrived safely. My experience with 3.5" displays has been "mostly broken".
Whinge to the Ebay vendor. They will eefund your money.
David.
Unfortunately I'm in the US, but thanks a lot for the offer, much appreciated!
Eh, I blame my inexperience more than a bad vendor, for me buying a cheap shield in the first place, but I already got a refund for the shield with the bent pins. I'll look more into those ILI9225 displays, and probably keep trying to see if I can find a fix for this cheap shield as well (if there is some work around the drivers and modified libraries I've found).
Thanks a lot for your help!
You can straighten a bent pin. Broken glass Touch Screen is not recoverable.
Go on. The easiest solution is to buy 8MHz Pro Mini (3.3V), Due, Zero, ...
No need to worry about level shifting.
You will find a SPI ILI9225 display on Ebay. It contains a level shifting buffer. And it simply plugs into the Power + Analog Header. (bit-banged SPI). Or you use flying wires to the hardware SPI pins.
But quite honestly, 240x320 is a more convenient size.
David.
Oh, great! Yeah, I did straighten the pins, but good to know it's likely more a software problem than hardware. I'll definitely look further into that. And thanks for the info! Will certainly keep all that in mind
