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Storing a splash-screen in EPROM?

PaNiC

New member
I gave these old EPROM-chips lying around and i want them to do something better, namely loading a splash-screen into my parallell display att startup and then stop when the regular prog wakes up. How would i go about it? I´m totally useless at designing circuits but i do know how to follow a schematic :)

Please help, this could be something for everyone to enjoy :)
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ip_freely

New member
hmm,

eproms are usualy UV reprogrammed using VERY expensive equipment!

now, if your refering to EEPROM that is different, however that still requires a LOT of in depth knowledge to set up.

first your going to have to get a hold of a way to encode the data onto the chips. then your going to have to set up a way for the chips to send a logo to the lcd when there is voltage going through the parallel port.

im not saying this is impossible, it is possible, but it will require a LOT of detailed knowledge about parallel ports, eeprom and parallel lcd's.
 

CF Tech

Administrator
The hardest part would be initializing the LCD controller. You could store all of the commands in the EEPROM, but you would need some way to sequence their arrival to the data and control lines on the LCD.

If the EEPROM is an 8-bit parallel part (do not know of any, but could be :)), and you used the LCD in 4-bit mode (an LCD in 4-bit mode needs 4 data lines and 3 control lines) then you may be able to just pre-load the EEPROM with the correct sequence of data line + control line information, and then use a simple timer (555 like) clocking a counter connected to the EEPROM 's address lines. The 8th data bit on the EEPROM could shut down the 555 when the initialization and boot screen are done.

Generally a small micro is much easier, and then you have just duplicated some of the functions of one of those serial interface daughterboard units. Although that particular one still does not do a boot screen :rolleyes:.
 

synopsoid1

New member
Splash Screens

Hello,

It would not be hard designing a simple circuit using a PIC Microcontroller and the LCD. I am currently working on a project. I'll make the source and schematic available as well as the baord when I am done. It will have a serial interface (RS-232 9600Baud) and be able to handle most of the basic functions. You would be able to store your Custom characters in the PIC as well as Displaying the splash screen after the display is initialized.

Currently I am writing the code in Hitec PICC Lite for a 16F84A-04 There will be a minimum number of external components. This will be a simple "back-pack" created on a single sided PCB (Yes! Single Sided so you can etch it at home!). Right now the PCB is 4.5 cm x 4 cm (approx 1.75" x1.5") and all that is missing are 2 diodes. I am guessing the board will end up 4.5 x 4.5 in the end with all the components.

Currently it does not have software controlled backlight or on-board voltage regulation.

Keep watching the board for more information!

-Mike
 

PaNiC

New member
Now that sounds like something for me! =)
I like building stuff@home and i´m always poor =)
Keep me updated plz
 

synopsoid1

New member
Schematic and PCB Layout complete.

I have finished the PCB layout and Schematic. Just need to finish the software for the PIC now. SHould be trivial as I have most of the LCD Routined down already. Just need to make the software compatible with some other "back-pack" or serial display. (Matrix-Orbital.Wirz,Scott Edwards..)/

Attached is the board layout (pdf) and schematic (gif).
 

Attachments

synopsoid1

New member
My press and peel blue came in (http://www.techniks.com/) and I etched my v1.0 board (with a minor revision for a different, smaller contrast pot).

Version 1.0 of the board works. Initializes the LCD and displays a "splash" screen. The serial IO is working. Now all I have to add to my code is the Matrix Orbital or Crystalfontz serial protocol code. This will take some time to get working 100%.

I need to get smaller drill bits next time around for drilling the PCB.

I will post again shortly with the updated board and the code I have so far.
 

ginvent

New member
More fun information

Just for fun, if you look at the ATMEL AVR parts using the Codevision C compiler ($99 for a compiler is CHEAP), they have a code auto wizzard that will allow you to attach a parallel LCD screen to most of the ATMEL parts AND it has C routines to drive the LCD display built in.

Or, the parts have built in UARTs that once activated, you literally use the C command:

printf("Hello!!!"); // and it will print happily out the uart.

You don't even need the RS-232 level converter because you can use the direct data_in pin on the serial display bypassing the RS-232 level converter... so 0-5 volts will work just fine.

Now how is THAT for simple! :cool:

I used to love PIC parts, but the AVR's have so much more to offer.
 

synopsoid1

New member
Re: More fun information

ginvent said:
Just for fun, if you look at the ATMEL AVR parts using the Codevision C compiler ($99 for a compiler is CHEAP), they have a code auto wizzard that will allow you to attach a parallel LCD screen to most of the ATMEL parts AND it has C routines to drive the LCD display built in.
But that compiler is $99 more thant the C compiler for The Pic...

PIC C Lite is free for 16X84's: http://www.htsoft.com
C2C Is free for all and Scenix: http://www.geocities.com/SiliconValley/Network/3656/c2c/c.html

Or, the parts have built in UARTs that once activated, you literally use the C command:

printf("Hello!!!"); // and it will print happily out the uart.

You don't even need the RS-232 level converter because you can use the direct data_in pin on the serial display bypassing the RS-232 level converter... so 0-5 volts will work just fine.
When a level converter consists of 2 diodes and a resistor or two resistors you don't really have to worry about the hardware. A $2.99 (PIC16F84A-04) part and a few cents in other components an you are done!.

I've been thinking about looking at AVRs...but I have too little time to re-write all my code for another Micro. Not to mention you can get the little 8-pin PICs for a buck. The features of the C Compiler look nice...but you can do the same thing with Pic C lite...you just neet to write getch and putch. Not to mention you may want to add features like scrolling etc.
 

ginvent

New member
Less parts the better

The less parts the better for me. A few diodes and such add more to my PCB which I am sure you know is a lot of work to do.

Well, not to nit PIC but;
You can get free C compilers like the GCC C for AVR. Plus the codevision compiler demo will compile just as much code afor free aalso. It's when you want to use the AVR mega's that you need the full version

You can get the AVR's for a $2, but to compare apples to apples, the PIC needs to be a flash version with the options the AVR's have.

Again, I love Microchip products, I just moved to ATMEL because of the overall enhancements in their options/in-circuit programmability/code space/speed/etc.

BTW, with the printf command, you can send ANY ASCII command down to the serial LCD. Example printf(" %c ", 12);
It will clear the screen. So scrolling isn't a problem.

All the Display control codes can be activated with the printf command. The benefit of using printf is the autoconvert to characters and numbers. doing a printf("X = %f", data); makes putting a float to the screen in 1 command. Using the putch, or puts, you have to convert the float to a character string (1 more command)

Converting your code? I assume you didn't write it in Ansi C then?

This reminds me of watching two people fight about Ford and Chevy.
 

synopsoid1

New member
ANSIC

Well...I would love to try the atmels...but where do you get them for $2? Please let me know where I can get them for $2 (without having to pay a $20 surcharge). What features do the $2 part have? I can program them with my programmer with no problem...Just need to get my hands on some Atmels.

For me I like the simplicity of the PIC..I'm not looking for tons of features. And I could just as easily tie the +/-12V RS232 directly to the pin...I just wanted a little overvoltage/current protection.

I have written my code in ANSIC (as much as you can for a microcontroller) but eventually you have to access a register or bit-bang I/O. Again some of the conversion would be easy...but it would take time. Not to mention if I need to learn the assembler for those atmels have 90-135 instructions.

I don't really want to argue over Microcontrollers...both definitely have their place. I have just used more PICs in the past. I suppose I could pick up the Atmel parts and run with them in a couple of days...but like I said up top...let me know where i can find the part (IN A DIP PACKAGE) for $2.

Do you have a website with some example projects you have done?

Time is money (and I just wasted at least $35 :)). Making boards is easy (drilling the holes...not so easy :D)
 

synopsoid1

New member
Re: Less parts the better

ginvent said:
...You can get the AVR's for a $2, but to compare apples to apples, the PIC needs to be a flash version with the options the AVR's have. ...
So..are you going to tell me where I can get teh atmel parts for $2?
 

synopsoid1

New member
Pic LCD Software.

PaNiC,

I made the board but was not happy with the layout. I may do another rev. As for the software some other things came up that needed to be worked on. I still plan on doing this but it will take some time. If you like I will e-mail you the C code. I found a problem with the serial connection on it as well and have revised it to something more stable (and cheaper).
 

ginvent

New member
$2 Atmel parts

Well, when you stated them, I assume you meant more than one. Digi-key sells them in a qty of 1 for $2.47. If you need a few more than 1, All American Semiconductor can get you below $2 for a qty of 10. Digi-key can get you under $2 for a qty of 25 or so. But your right digi-key will charge you $5 if your order is under $25.

Avnet-marshall carries them for about $2.05 in low qty.

If your having trouble finding parts at good prices, I recommend using www.freetradezone.com (used to be partminer), then do a price search, call the supplier and ask what kind of deal they can work for you.

I have used many pics in the past also. I only noticed the ATMELS when my friend, an All-american field apps engineer, helped me find a new part that would lower my power, increase my processing power, and reduce costs.

My latest design can be seen at http://www.measurearea.com

I have a lot of other designs, but they were with different companies that mainly developed demostration boards to show off the latest silicon we were designing.

The only thing I never looked into with the pics is how easy it was to integrate SRAM to the micros. The ATMELS have built in SRAM controllers, but I don't recall seeing that on the PIC side. Most people don't need much SRAM, but our data collection projects do. Then again, if your using a $2 part, you probably don't have enough I/O to do SRAM. :D

Also, just a side note, you mentioned you did your own PCBs?
There is a company in Canada www.boardman.cc
They usually have a Super-proto special for $70-80 which will get you a few PCB's made, with holes (hehe), double sided. The exchange rate to Canada is good, so I use them all the time for quick runs of prototypes.
 
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