144 LED Games Console Project

[mtripoli]

I don't know if it's the language barrier or what, but hell, I'll give it a shot, again.

First, I don't know what the files are you keep posting, they have SCH and BRD extensions. I'm guessing that these belong to Eagle or something. So look, not everyone has these programs. I have Orcad and it uses the same extensions which means nothing. Save the output as PDF or jpeg or something that all PC's can open.

Second, I've posted the schematic from the system that ART did at the beginning. It looks like you or someone decided to change the drive scheme from emitter follower to open collector (if you don't know those terms stop working on this project and get a basic electronics book and do some reading). That's fine if you understand what you are doing, but as far as I know the code that Art wrote won't work with this design. So I'm guessing that after someone answers your "R19" question and if you get though construction of an actual PCB and get it stuffed you'll blindly run the code and it won't work and a new thread will start about how the code is wrong. But I digress...

As drawn in the schematic posted by "funnydrummer" R19 is connected to the column (anode) pin 13 of LED module (LED6) and to the pin 2 of the PIC which is pulled up by a 10k resistor. As drawn it does nothing. When you push the button tied to R30 the whole line of leds will light, that's it. There are column drivers through resistors R20-R29; I have no idea why they are different on LED1,3 and 5 than on LED2,4 and 6 but hey, whatever. The row connections are different on LED5 and LED6 as well. It may be some "Charlieplexing scheme" or it may simply be someone screwed up drawing the schematic, eh who knows. As its drawn it will be lots of fun to code for (that's sarcasm).

I'm not trying to be an a-hole or anything, but it sounds like you don't really know what you're doing and have jumped in way over your head. Simply copying schematics and making PCB's might work for little opamp audio circuits and such, but there are concepts going on here that you don't have the grasp of. Have you done a simple project yet and just blinked an led?

Also, these schematics are drawn horribly. Wires running all over the place like that is a recipe for disaster. Look at the schematic I drew; clean, clearly labeled, etc.

The original schematic:
http://www.scarydesign.com/144led/144LEDSCHEMATIC.pdf

[funnydrummer]

As drawn in the schematic posted by "funnydrummer" R19 is connected to the column (anode) pin 13 of LED module (LED6) and to the pin 2 of the PIC which is pulled up by a 10k resistor. As drawn it does nothing. When you push the button tied to R30 the whole line of leds will light, that's it. There are column drivers through resistors R20-R29; I have no idea why they are different on LED1,3 and 5 than on LED2,4 and 6 but hey, whatever. The row connections are different on LED5 and LED6 as well. It may be some "Charlieplexing scheme" or it may simply be someone screwed up drawing the schematic, eh who knows. As its drawn it will be lots of fun to code for (that's sarcasm).

Look mate, stop whining the whole time and at least have a look at the last schematic and board I posted.
I can't remove the older post so I'm sorry for that schematic. The power LED was wrongly connected indeed...
Since I'm only using 144 LEDs + a power LED, there are a lot of LEDs wich aren't connected. All unconnected LEDs will be covered with tape.
That way you don't have to worry about flashing LEDs. The bottom-right LED is going to be used as power LED, simple as that.

I'll let you know if it works though. I'm fixing the last errors now and then I'll be ordering a PCB.
Not everyone's as skilled as another, no need to flame. Just try to help us out or don't bother posting... ;-)

[mtripoli]

LOOK MATE. If anyone here is whining its the people that know nothing about electronics, tackle these kinds of projects and then get on here or any other board asking for help on the simplest of things. I didn't "flame" anyone; if you go back and read the post without attitude you'll see that I wrote it tongue in cheek. As for "helping you out" I re-posted the board file and schematics after YOU and Svrzic sent me PRIVATE MESSAGES asking for help. I don't reply to private messages; the board is here for everyone to read all questions and see all replies.

Part of the problem with all of this is people RUSH to drawing some schematic in some software they downloaded for free, usually riddled with mistakes, post it to a board like this, confuse others that don't have any experience either and when someone more knowledgeable points out the mistakes you get defensive and start up with "help us or leave". How about you help yourselves FIRST by going online or better yet buy a book on basic electronics and get a fundamental understanding of these things (if I recall you said in your private message you needed this for school). There is FAR MORE TO IT than simply copying someone else's schematic, etching a board in the sink and then loading someone else's code and crossing your fingers that it will work.

As for "at least have a look at the last schematic and board I posted" I can't. You evidently posted Eagle schematic and board files. Not everyone has or uses these tools, and I'm not about to load up some software only to use it as a basic viewer. This is why we post in a neutral format like a simple jpeg or even a PDF so everyone can see it. Do yourself a favor and post your "latest" in something we can all see, and then those "more skilled" can have a look and potentially stop you from making a mistake that'll keep your project from working.

[funnydrummer]

LOOK MATE. If anyone here is whining its the people that know nothing about electronics, tackle these kinds of projects and then get on here or any other board asking for help on the simplest of things. I didn't "flame" anyone; if you go back and read the post without attitude you'll see that I wrote it tongue in cheek. As for "helping you out" I re-posted the board file and schematics after YOU and Svrzic sent me PRIVATE MESSAGES asking for help. I don't reply to private messages; the board is here for everyone to read all questions and see all replies.

Part of the problem with all of this is people RUSH to drawing some schematic in some software they downloaded for free, usually riddled with mistakes, post it to a board like this, confuse others that don't have any experience either and when someone more knowledgeable points out the mistakes you get defensive and start up with "help us or leave". How about you help yourselves FIRST by going online or better yet buy a book on basic electronics and get a fundamental understanding of these things (if I recall you said in your private message you needed this for school). There is FAR MORE TO IT than simply copying someone else's schematic, etching a board in the sink and then loading someone else's code and crossing your fingers that it will work.

As for "at least have a look at the last schematic and board I posted" I can't. You evidently posted Eagle schematic and board files. Not everyone has or uses these tools, and I'm not about to load up some software only to use it as a basic viewer. This is why we post in a neutral format like a simple jpeg or even a PDF so everyone can see it. Do yourself a favor and post your "latest" in something we can all see, and then those "more skilled" can have a look and potentially stop you from making a mistake that'll keep your project from working.

Nevermind. Thanks for the reply anyway. ;-)

I'm not a professional, but I tend to learn from people who DO know a lot about electronics.
And I'm not going to copy any code. The hardware is the 'easy' part, I think.
I'll post the source for my version of snake (in C) when everything is fully working.

In the zip file you can find the board file I've sent to the PCB company.
I hope everything's working, if not, I'll let you guys know.

Schematic:


Board:

[mtripoli]

@funnydrummer: You don't need resistors on the base of an emitter follower so you can delete those entirely. If you're opposed to using resistors for current limiting (which is the only reason I can see to stack up diodes like you have from the supply) you can use a constant current regulator (CCR) device like the NSI45020T1G from ON Semi (Mouser, $0.34 each). If you use a CCR device you can get rid of all the transistors and resistors entirely and use just the CCR. Put one per drive segment (they can be used high side or low side, see schematic). Run the PIC from 5V and there you go. And why would you post C code on the Pic Basic forum?


@Svrzic: The PDF schematic that is posted is FOR DISCRETE LEDS. Regardless if you buy them packaged or use discrete components the schematic is the same. I think you said you're 17 years old. Good for you for your interest in electronics but it sounds like you need to back up a bit and start with something a little easier.

LEDMATRIX_CCR.pdf

[mtripoli]

This is really an edit, time expired when I went back...
***********************************************
@funnydrummer: You don't need resistors on the base of an emitter follower so you can delete those entirely. If you're opposed to using resistors for current limiting (which is the only reason I can see to stack up diodes like you have from the supply, (which is a really bad idea but I'm not going into that) you can use a constant current regulator (CCR) device like the NSI45020T1G from ON Semi (Mouser, $0.34 each). If you use a CCR device you can get rid of all the transistors and resistors entirely and use just the CCR. Put one per drive segment (they can be used high side or low side, see attached schematic). Run the PIC from 5V (voltage regulators are a good thing, why you wouldn't use one I don't know) and there you go.

You're going to need a 0.1uF on each Vdd pin, not just the one you have on the power supply line. While you're at it I'd put at least a 100uF cap on the power supply line as well. It doesn't look like you have a connector for doing ICSP so writing code and debugging will not be any fun at all (unless you like pulling a 40 pin part from a socket for every little change you make to code). If you plan on clipping to the PIC for programming you have no provision for isolating the Vpp line. There is no electrical reason at all for using pull-ups on two switches and pull-downs on the other two, as well as keeping track of that in code is unnecessary. You really should look at the schematic I posted. And why would you post C code on the Pic Basic forum?


@Svrzic: The PDF schematic that is posted is FOR DISCRETE LEDS. Regardless if you buy them packaged or use discrete components the schematic is the same. I think you said you're 17 years old. Good for you for your interest in electronics but it sounds like you need to back up a bit and start with something a little easier.

Attachment 6142

[funnydrummer]

@funnydrummer: You don't need resistors on the base of an emitter follower so you can delete those entirely. If you're opposed to using resistors for current limiting (which is the only reason I can see to stack up diodes like you have from the supply, (which is a really bad idea but I'm not going into that) you can use a constant current regulator (CCR) device like the NSI45020T1G from ON Semi (Mouser, $0.34 each). If you use a CCR device you can get rid of all the transistors and resistors entirely and use just the CCR. Put one per drive segment (they can be used high side or low side, see attached schematic). Run the PIC from 5V (voltage regulators are a good thing, why you wouldn't use one I don't know) and there you go.

You're going to need a 0.1uF on each Vdd pin, not just the one you have on the power supply line. While you're at it I'd put at least a 100uF cap on the power supply line as well. It doesn't look like you have a connector for doing ICSP so writing code and debugging will not be any fun at all (unless you like pulling a 40 pin part from a socket for every little change you make to code). If you plan on clipping to the PIC for programming you have no provision for isolating the Vpp line. There is no electrical reason at all for using pull-ups on two switches and pull-downs on the other two, as well as keeping track of that in code is unnecessary. You really should look at the schematic I posted. And why would you post C code on the Pic Basic forum?

Thanks a lot for the suggestions, I really appreciate it!

Too bad I already ordered the PCB, it's a big one so it would be a bit costly to order a second one.
I might edit and optimize the schematic/board in the future, but for now I'm just hoping the current board will do.
The next thing to do is programming. ;-)

Good point though, this is forum isn't called PIC-C...
I'm not familiar with basic programming, that's why I'm just gonna go with C.
I thought it would be nice to post the source anyway, just for the people who prefer C over basic.