Go Down

Topic: Conceptual Project Guidance (Read 1 time) previous topic - next topic


I thought the same thing with the touchscreen....I saw that adafruit offers a little bit smaller lcd (non-touch) for half the price...I was considering that option.  This screen looks like its built ready to plug straight into the arduino....and looks like its super easy to set up and is very compatiable with arduino....It's great guidance and Ill for sure use this on my feasibility prototype.

Adafruit looks like a great resource. Thanks!

I relies that these lcd displays have there own microcontroller, and like you said I could make my own by piecing it together and code the whole thing.  I would imagine if I get to the production stage of this project I will probably take that route to be cost efficient.  Would you agree?  how difficult is this to do?  Im just trying to educated myself on a field I don't have alot of experience in. 


I have been in the same boat for some time. My enclosure has a very limited amount of space and I am limited on the enclosure size so I can't just get a bigger enclosure. So I have done a ton of research to try to find a 128 x 128 that uses a controller that someone has already created a library for. Interestingly enough, the Adafruit 128 x 160 uses an ST7735 controller. Their library is also very inclusive. They sell both the display on a breakout with SD ($25) and the bare display ($10. It's $8 on Digikey). So I have been searching for a 128x128 that uses the same controller. I have found a few but they are all China direct. The upside being cost (~$2 each for qty 100), the downside being China direct.

So the challenges associated with buying the bare display are two-fold. First, finding one with a controller that has some existing support since creating your own library for a display from scratch would be TOUGH!. There are a lot out there, you just have to find them. The second being that you are going to have to connect the Flat Flexible Cable (FFC) to you board. Not an easy thing to do. Direct bar soldering is the best option but you can get FFC connectors that are SMD if it will work in your system. Usually the cable is wrapped underneath the display which precludes the use of a connector but if your layout allows for a connector, I would go that route.

Newhaven sells a collection of boards that will help you prototype if you find a bare display that works.

To try to answer the other part, most display's have controllers on board that drive them. However, there still needs to be some sort of coding to make them work. The controller is in it's rawest form basically setting the condition of the all of the pixels. It takes someone smarter than me to translate that into commands that can be sent from the arduino to get results. That's where libraries come in. There are a couple of generic libraries available that can interface with different controllers but you will need to do some research before you go this route. Look through the display section of these forums. Display controllers are most often broken down by the size of the display so keep that in mind when you are looking. This is critical, just because it looks like it would fit, it may have some really obscure controller that you will not be able to talk to.




Display libraries aren't technically difficult.. just very, very tedious.  In most cases, once you have the low-level stuff done, you can re-use the primitives.  (I.e., work out how to draw a pixel, and you can copy the line and shape drawing parts from an existing library.)

The hard part is deciphering the datasheets, since they often seem to be written with the single purpose of making it as challenging to understand as it was to design.

Anyone read the SD specifications doc?  Nothing is spelled out in one place.  You can't implement anything from it without flipping between three or four sections to compare notes.  And there's a lot of guesswork required where details have been glossed over, or redacted (for licensees only).

Go Up