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Newbie and CFAG320240C0

wessgates

New member
Hello,

I am trying to teach myself microcontrollers and LCD stuff. I just purchased a CFAG320240C0. I have reviewed the spec sheet. I am using an AVR STK500 dev board with an Atmega 8515. I am wondering if there are any tutorials that do a bit more hand holding than the spec sheet? Like "A getting started with Crystalfontz LCD guide" etc? My first concerns are how to wire this thing up to the 8515? My second worry is power supply to the LCD itself. It appears from the data sheet that I just need to supply +5V and then the LCD electronics generate the negative voltage for itself depending whether I use External Control or On-Board pot? How about a document that talks about the difference between 8080 mode and 6800 mode? It seems like such basic data would be centralized somewhere? My goal is to build a spectrum analyzer but with a little twist :)

I would appreciate any guidance at all!

Kind Regards,

Wess
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wessgates

New member
I saw this thread and I am not interested in taking the risk of hooking it up to a parallel port because it becomes non supported. I am completely new to this area and I am not going to double my risk. Do I understand that there are no documents on how to work with LCDs/MCs ? If so this is contrary to what I was told before I purchased my LCD by the sales rep.
 

CF Support

Administrator
I wasn't saying that you should connect it to a PC, but that you should port the macros and initialization code from CFAG_WintestDlg.cpp to your microcontroller, and follow the logic used in the functions there. If you send an email to support@crystalfontz.com we can discuss this in more depth.
 

CF Tech

Administrator
Yes, we do not recommend using the parallel port unless you have no other avenue.

You already have the AVR demo board which is much better than the parallel port approach.

There are three things to watch out for:

1) Vo: The pot on the back of the module will handle the voltage to pin3. Adjust the pot until pin 3 reads about -19v (Vlcd = 24v).

In general, all of the pins need to have attention paid to them (see page 11 in the data sheet) but Vo trips up a lot of developers.

2) Backlight: Do you have the CFAG320240C0-YMI-TZ or the CFAG320240C0-FMI-TZ ? Once we know this, we can let you know how to hook up the backlight.

3) Initialization code. One way to get the initialization code is to port our parallel port code to your 8515. There may already be code out there that has been ported to the AVR. Here is a search to start:

http://www.google.com/search?q=SED1335+avr
 

wessgates

New member
Please provide qucick insight between 6800 and 8080

Hello,

Could anyone provide a reference to what the differences are between 6800 and 8080 mode? A quick blurb would also be appreciated :)

Thanks,

Wess
 
In 6800 mode, there is a R/W signal and E signal. You set the mode you want for read (R/W = 1) or write (R/W = 0), and then the E signal is the data strobe, active high. For read mode, the data from the display is put on the bus while E is high; for write mode, you put data on the bus and then take E high then low again. The data is clocked to the display on the falling edge of E.

In 8080 mode, the R/W signal becomes "W", the write strobe active low, and the E signal becomes "R", the read strobe, also active low. In writing, the data is put on the bus and W is taken low then high again, and the data is clocked on the rising edge of W. For reading, the display puts the data on the bus when R is low.

This information is given plainly on pages 7 and 8 of the data sheet. There are diagrams on pages 79 and 80 that show the timing information and waveforms.
 
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