I have been working on an Arduino project where I am using a 4 digit 7 segment display. The one that I have picked for my project based on size constraints is this Lumex one which I've attached the pdf of the datasheet. To drive it I picked an ay0438p and used the Supercrab library (which was insanely helpful!).
I have gotten everything to a place where it works exactly as I intended it to but the problem I am working on now is how big the ay0438p is and how much space all the connections take up. I've read a bit about multiplexing and charlieplexing and see that if there is anyway to simplify what I'm doing that would be the way I need to go about doing it. But I was wondering if it would be possible to implement that with an Arduino and this display I am currently using?
I thought maybe there is a way by tying in some transistors, and I'd probably have to change the library?
But I was wondering if it would be possible to implement that with an Arduino and this display I am currently using?
No. The Arduino doesn't support the same sort of signal that you need to drive an LCD.
Driving a LCD is a complex process and I am not even sure that your driver chip is going to drive your display.
The best you can do is to cascade two LCD driver chips like it shows on page 3 Figure 6.
This is the sort of thing you have to deal with in driving an LCD. These are the diagrams from an article I wrote back in November 1987 about how to tap off and read segments from an LED being driven by something else.
When you say signal are you referring to the signal for the backplane? If that is the case, the AY0438 chip allows you to hook up a capacitor which enables an on-chip oscillator.
The way I am currently doing it has seemed to work so far(not to say that it is correct by any means).
But I guess what I'm understanding from your comment is that I probably need to look at a different type of display like maybe an LED if I am to accomplish what I was wanting to try to do?
Well I don’t know what exactly you are trying to do, but if it is just to display all the segments and what you have is working with one display driver I would cascade another display driver on to it to mop up the extra segments.
I don't think you can do multiplexing on LCD displays. You can do it on LED displays and this would reduce the wiring, especially if you use an led driver chip like max7219 or ht16k33. Your digits seem to be 13mm or 0.52", and you can get led displays that size and larger (but don't go too large or you may not be able to use the chips I mentioned and things get more difficult).
You should know that led displays will use much more current than LCD, this may be important if you are designing something battery powered.
It is actually described in Mike's diagram above, now that I come to look at it, but even more levels involved in the case of the HD44780.
Which relates to why I so often have to explain that problem with the contrast potentiometer connections and a mistake propagated by people who simply do not understand how the LCD works.
I'm not going to pretend I'm at a level to fully comprehend what I'm looking at with those waveforms , but I did watch a video last night from eevblog that demonstrated that it is possible. Just probably beyond what I am capable of doing myself at the moment.
You should know that led displays will use much more current than LCD, this may be important if you are designing something battery powered.
This is good to know! It is powered with a battery. I also really like the look of the glass display that I have with the LCD more than what's available for LED displays.
I guess for the meantime I will leave it alone, because it works as is, and I have a lot to learn before I could attempt to mess with something like that. I just wish I could find more examples of projects where people have worked through this.
I just wish I could find more examples of projects where people have worked through this.
That has to tell you something doesn’t it?
This is why most hobby and indeed professionals user opt for an integrated driver / display solution.
I couldn’t find any information when I wrote that article that is why I had to work it out for myself. Note that there are quite a few different types of displays and the all require different waveforms to drive them.
, but I did watch a video last night from eevblog that demonstrated that it is possible. Just probably beyond what I am capable of doing myself at the moment.