Well it was me that bitched about starting an electronics forum and this is the reason why.

I like electronics but i have little experience when it comes to digital. I have built regulated power supplies and thats about it.

I have an idea to build a simple device to access and store bytes on a serial eeprom (24AA16 by microchip) that can be displayed on a 2 X 16 LCD display by use of a simple keypad.

The problem is i have never attempted this before so i don't really know the interfacing principles or the actual components required.

Besides the discrete items such as pull up resistors, power supply, caps, a clock ..what components are required?

AAAAny help appreciated.
Posted on 2003-03-30 21:07:29 by IwasTitan
Well, I only have some bits of basic electronics knowledge but I think I've seen some drawing for a programmable RAM/EEPROM and some 4 diods as "stdout", I'll take alook in the book and see if I can scan the drawing and the "how to build"-part (in swedish though), I'll have to see if there is some copy limitations for the book's contents.
I think the basics are the same for RAM and EEPROM, but I don't know.
I found an drawing of a circut that uses a RAM chip, and will loose it's programmning at power loss. From what I can read out, there is three ICs (one 74132(schmit-trigger chip, chip refernce says: "Quadruple 2 input nand schmitt trigger"), one 7493("4-bit binary counter") and one 7489 (a 16*4 bits RAM, "64-bit Read/Write Memory")).
After reading the copyright notice, I see that it's clearly stated the copying is prohibited. (sorry)
Posted on 2003-03-30 22:55:28 by scientica
A PIC would be one likely candidate for the interface, but that means you'll need a programmer for it.

I seem to remember the Basic Stamp has a serial interface built in, so you can code it right off a PC. So for a higher per piece price (and having to code it in Basic) you get a simpler implimentation.

PICs also have a sharp learning curve, slightly offset with the free compiler/simulator you can download for free.
Posted on 2003-03-31 00:30:35 by Ernie
i guess you have had the schematic, dont you, IwanTitan?
if not, then googling for lcd interfacing topic. in past the only source i got to made that up is from the net, no other place to go :grin:
btw, interfacing lcd dont need any other component instead your pic, period, and maybe a r-pack for pull-up. the program is so fixed that you'll get no fun experimenting with it :grin:
Posted on 2003-03-31 06:01:05 by dion
I would go the PIC route myself. I may join you for a bit if you do... I have a handful of 2x16 LCD's myself with the standard HD44780A00 controllers on the back of em. I origionally looked for a PIC source, but came up short and gave up trying after a few days. I have the spec for the controller somewhere on my HD too.. (i think).

As well I can offer you a pic programmer schematic... works well on the 16F84 and a few others.

:NaN:
Posted on 2003-04-01 18:29:38 by NaN

I would go the PIC route myself. I may join you for a bit if you do... I have a handful of 2x16 LCD's myself with the standard HD44780A00 controllers on the back of em. I origionally looked for a PIC source, but came up short and gave up trying after a few days. I have the spec for the controller somewhere on my HD too.. (i think).

As well I can offer you a pic programmer schematic... works well on the 16F84 and a few others.

:NaN:


This will be a summer project when school is over at the end of april. At present i am reading pdf files on the PIC18F series by microchip.

I have a PIC18LF8720-I/PT and a PIC18F8720 $6 US dollars each.

The things are very small and I'm sure a simpler micro controller would do the job and might be in a larger DIP container that is more conducive to hobbiest soldering.

Suggestions of where to get simpler and larger DIP style microontrollers would be helpful or schematics relating to interfacing to the HD44780A00 type LCD.

Thanx to all.
Posted on 2003-04-01 19:04:01 by IwasTitan
My choice for spare parts is always Digi-Key . Low min order, prompt shipment, all good. (They even called ME today to see if their engineers could be of any assistance!) (Of course it helps I just placed a $4,000 order for PICs from them)

Otherwise, right in Microchips site they have a pricing and availability tab for each part. That beings you up a list of several resellers with their current stock counts and price.

The flash devices are a good start, you can skip the UV eraser with them. I'm not sure if they come in nice DIP packages (probably do).
Posted on 2003-04-01 21:48:24 by Ernie

(Of course it helps I just placed a ,000 order for PICs from them)
Wow.. and what do you have to do with it, a supercomputer? A ultrarobot? Goldrake's mind? ;)
Posted on 2003-04-02 01:41:48 by Maverick

Wow.. and what do you have to do with it, a supercomputer? A ultrarobot? Goldrake's mind? ;)


Maverick...sarcasm is for the World Affairs section.

Maybe Ernie is starting a business.

People here are serious about electronics.

ummm what was your question or helpfull insight?
Posted on 2003-04-02 18:04:35 by IwasTitan

Maverick...sarcasm is for the World Affairs section.


I disagree. I get the feeling you are very eager to learn new things. But fun an humor is always welcome. I dont think he was being malicious, if anything i would say he sounded like Ernie on any other day of the week

(( :grin: :tongue: His jokes are wierd too :tongue: :grin: ))

:NaN:
Posted on 2003-04-02 20:29:22 by NaN
Ok I'll shutup.

I guess me hanging in the WA section too much has got me defensive.
Posted on 2003-04-02 20:39:17 by IwasTitan
Umm, $4K of PICs means a full reel of PIC16C620A-40 chips.

And no, they all don't go into the same product. They go into 2500 coppies. One per.





Now if I could just get Mav to sound more like me in the WA section <grin>
Posted on 2003-04-02 22:51:04 by Ernie

Hi IwasTitan, you wrote:
Maverick...sarcasm is for the World Affairs section.
I wasn't being sarcastic at all.. even less malicious.
I may be tough on Ernie on the "Warmongers vs The Rest Of The World" forum, but in the other forums it's completely different.

You may agree that mine was a genuine curiosity: I was fascinated to know what Ernie had planned to do with the 4000 PICs.
In the past I had some plans to build a kind of parallel supercomputer with 18F PICs, but I quickly realized that a single AMD K7/K8 would be better. Parallel computing is fascinating nonetheless anyway. :)
ummm what was your question or helpfull insight?
And yours, other than pointing your finger on me? ;)




Hi Ernie, you wrote:
Umm, K of PICs means a full reel of PIC16C620A-40 chips.

And no, they all don't go into the same product. They go into 2500 coppies. One per.
May I ask what each device does?

When I'll have free time (if it'll ever happen) I'd like to start some hobbyst robotic projects.




Regards to all (NaN in primis).
Mav
Posted on 2003-04-03 01:21:52 by Maverick
Hi, IwasTitan,

I once connected a 2x24 character HD77480 based LCD display to a PIC16C54. Of course, the PIC type is not really relevant. Changing the size of the display (in SW) is really nothing more than setting/ resetting some bits in a command.

I have some schematics in Eagle and the working code for it. Let me know if you need any of this stuff.
But I think you should try to do it yourself. You'll learn a lot and have fun at the same time. When done, you'll feel a lot better about yourself. I know I did.

It should not be a problem to hook up an EEPROM. Start by reading AN567, AN619, AN683, AN530 and a few others from Microchip.
Here is the link:http://www.microchip.com/1010/suppdoc/appnote/alpha/index.htm

There was also an Appnote about connecting an LCD display to a PIC, but I could not find it. Go through the list, you may be get lucky.

Good luck!
Posted on 2003-04-03 13:53:40 by VVV