PCB DESIGN - All In One v2.5 - 32 inputs with 74HC4851

[gastric]

I agree with you about my specific setup. And I think someone reading the dozen posts in this thread about printing issues would realize that. Or maybe not. I edited my Word directions to document the theoretically correct scaling, and note I set it to 2.8" for my specific printer.

But the fact remains that PRINTING GIF in general is problematic. You can't just open it in MS Paint and print. You can't just right-click the GIF and choose Print, or you get the goofy Windows Photo Print Wizard which bungles it badly. It's simply difficult to print PERIOD. And saying "turn off scaling and set to 600dpi" isn't enough directions. Just look at all of the people that have posted printing issues in the forum. So hopefully the PDF and the 3 pages of printing conversations here will help others.

[dmitri]

I agree about GIF because files of this format don't carry DPI information in it, but I disagree on using MS Word format for this. There are better alternatives to that format, e.g. PDF.

[jman 31]

Glad you got it Gastric. I agree that PDF will be the most accurate sample of what you start with, but go with what ever works for you. One thing that may really help is posting the outside dimensions of the pcb with the pdf so that it will be easily checkable for people trying to duplicate it.

[gastric]

I followed the paper recommendations here http://www.fullnet.com/~tomg/gooteepc.htm and used the Staples glossy inkjet photo paper. My first transfer worked great with the exception of the edges where I apparently didn't iron very well, at least that's my assumption since the rest of the transfer was beautiful and consistent. With the exception of the edges I have a single potential problem related to the functional traces as noted in the last photo. There is a small unmasked area that seems too small to be unmasked on purpose and is also evident in the original GIF. Should I mask that in with a Sharpie or leave it as is?

[dmitri]

You can disregard it. It is a "fill in" with a sole purpose of saving etchant.

[elrules]

Don't worry, use a permanent pen to fill in that gap. I used it for my errors on the transfer and it worked well. But dmitri is right, you don't need that "connection"

[bobnickelson]

I've having a bit of trouble with my board. I assembled it all together, connected the Iscp for the usb and the program recgonized it and i successfully wrote the firmware to it. I then hooked up the Iscp for the atmega and choose the correct settings, but the program said that it didnt recognize the atmega, if i hit ignore i still was able to write to it successfully (i even read what i wrote to verify) However the usb does not work, and the contrast on the screen doesnt change either (tried turning the pot). On a side not when i was putting the components onto the board i noticed that i had an extra cap left over, a 4.7uF, which the top gif of the board doesnt mention nor is there any place to put it.

[dmitri]

I've having a bit of trouble with my board. I assembled it all together, connected the Iscp for the usb and the program recgonized it and i successfully wrote the firmware to it. I then hooked up the Iscp for the atmega and choose the correct settings, but the program said that it didnt recognize the atmega, if i hit ignore i still was able to write to it successfully (i even read what i wrote to verify) However the usb does not work, and the contrast on the screen doesnt change either (tried turning the pot). On a side not when i was putting the components onto the board i noticed that i had an extra cap left over, a 4.7uF, which the top gif of the board doesnt mention nor is there any place to put it.

Is it Atmega32? Is the crystal 20MHz?

[bobnickelson]

its an atmega644, with a 20 MHz crystal. I bought all the parts that were included in post with the mouser part numbers a few pages back. I'm going to make a thread specfically for my megadrum build and the issues that i'm having with it, since its not really on topic for this thread.

However a 4.7uF cap is included in the parts list, but never used. I even counted all the caps on the board 12 total, and there is 13 in the parts list.

[gastric]

Sorry if I wasted $0.33 of your hard earned money (seriously, I am) though I'm sure your concern is that you have an extra part that might possibly be required somewhere. If there's any problems with the Mouser.com order list you can mostly thank me for that. Someone else pointed out that I had a surface mount part on there which I already corrected. I also modified the Atmega to use the 644 since it was cheaper and more feature rich.

I'm still working on my board so I won't get to ironing out the bill of materials myself for another week or so probably. I've already noticed I had some notes about the "jacks" board needing 2 more sockets, which is true, but I had the note next to the wrong socket. So I'm short some IDE sockets and have some extra 40pin TULIP sockets.

There's absolutely positively the potential for other parts issues in the list. But that's why I started the list as it's completely impossible for the average person to source the components.