Looking for a non ucontroller sollution

I caught the unnecessary diodes as I was completing the schematic. Thanks for the tip on shorting the power supply, I was thinking the diode would prevent a short because it didn't reset the 299 when I put it in. Here is the updated schematic, if you have any tips, tricks, or anything else on eagle, or anything else please let me know.

Thanks Again,


C

Okay. Now looking closer, the bottom 555 is getting its power (VCC) from the output of the last shift register. For one thing, the voltage at the output of the shift register is not quite 5 volts for powering the 555. Also, the added load to power the 555 on that output will cause the LED on that output to be dimmer than the other LEDs.

In addition, the 555 circuit on the bottom doesn't look right to me. I think the resistor and the capacitor are swapped from what they ought to be and the diode should be removed. I think then you can connect pin 3 of the timer directly to the CLR inputs without the transistor pair. I am assuming you want all the LEDs to turn off after a delay from the time the last LED turns on.

I checked out your suggestions on the breadboard. (as a portable test setup I'm using 3 AA batteries to power my setup, only using 1 299 on the breadboard as a test setup since I only have one breadboard right now). I am using I/O 7 to start the on delay 555 (lower) or to go to the DS0/SR (pin 11) of the next 299.
I haven't tried to swap the resistor, capacitor, and/or the diode. I found the circuit at 555 Timer, Operation. . I tried to move pin 8 to power and that didn't work. I haven't analyzed the circuit yet to understand it yet (been to focused on the entire circuit, I'll need to do that so I will remember it for future projects).
I came up with the idea of using the transistor (or at least I didn't find it on the web) for the reset of the 299's. My theory on that was that pin 3 of the 555 goes low (which would pull the MR (pin 9) of the 299 low) when not active, using the transistor would let the diode (now the 10k resistor) keep MR high until the lower 555 timed out.

I have this on the breadboard and just tested it all. It seems to work, but I need to get a bigger breadboard and find a suitable power supply so that I can do a full setup before I etch my double sided board (that will be another first for me).

Please let me know if my "theories" or "ideas" or research are flawed, not correct, best practice, inefficient, or could be improved upon.

Once again thanks, and ccurtis, you have saved many components from a smokey death, and the walls in my house from many skull indentations.


C

It's hard to argue with success.

The circuit you linked to is a good power-up delay circuit, and I can see why it just so happens to work for you, but it's liable to be unreliable and undesireable for the reasons I mentioned earlier. You are correct to invert the output state of that circuit for your reset signal to the shift registers using those transisitors. It's intended to be used as a power-up delay, rather than a signal delay, however. With my suggestion to swap the R and C and diode, you don't have those quirks and you don't need the extra transistors. BTW, I fogot to mention in my suggestion that VCC and the reset pins on the timer should be both connected to the power supply (VCC).

Have fun. It looks like a neat project.

I will swap the above mentioned components tomorrow and make sure they work for the setup. Thanks for your time, patience, and knowledge.


C

I'm having a little trouble with the board layout using Eagle. I drew the entire circuit out then switched to the board, while trying to move my components over to the board it keeps saying that the Lite version can not do that. Is there any tips or tricks on how to get my components on the board without the airways (or are they the airwires)? Then once the components are on the board, turn them back on and start my routing?

Thanks


C

zsh8me2 said:

I'm having a little trouble with the board layout using Eagle. I drew the entire circuit out then switched to the board, while trying to move my components over to the board it keeps saying that the Lite version can not do that. Is there any tips or tricks on how to get my components on the board without the airways (or are they the airwires)? Then once the components are on the board, turn them back on and start my routing?Thanks
C

Click to expand...

The schematic should be in one page only. Once you bring all these components into the rectangular confined board area(this cant be increased in lite version),you can do it
however, if you upload the schematic, it could be studied perhaps.

I attached the schematic in one of my earlier posts. Once I open the board everything is to the left of the enclosed board. I was able to enlarge the board area, but it took me over an hour to find places where I could put the components (about 20 components out 200+ components.

zsh8me2 said:

I attached the schematic in one of my earlier posts. Once I open the board everything is to the left of the enclosed board. I was able to enlarge the board area, but it took me over an hour to find places where I could put the components (about 20 components out 200+ components.

Click to expand...

You can increase the size of the box but a trial version will accept components inside the former area only and not beyond, even if the boarder shows more area.
I was asking for a .sch as eagle file not a .pdf version of the schematic. I saw the pdf.

Perhaps Bill of Blueroomelectronics.com is correct suggesting you to resort to Microcontrollers. Magnitude of work demands hardware reduction.

I dunno. Considering the large number of LEDs in this project and the small number of I/O pins on a µC, a substantial amount of external hardware would still be needed unless the LEDs are replaced with an integrated display, which may not be suitable in this case. In any case, at a minimum, each LED would need a driver transistor with perhaps a base resistor, which is what the shift registers could be considered to be, and in a comparable space.

zsh8me2 said:

I attached the schematic in one of my earlier posts. Once I open the board everything is to the left of the enclosed board. I was able to enlarge the board area, but it took me over an hour to find places where I could put the components (about 20 components out 200+ components.

Click to expand...

Resort to pcb123 from **broken link removed** Perhaps you need to make a new start.

zsh8me2 said:

Also, I'm trying to re-learn the stuff I have forgotten or haven't used in years. I will probably do this same project with a micro once I start with them just for a comparison....
C

Click to expand...

Let me say up front that I have a large bias in favor of uC's. I slap one on every project need it or not

Much of the 'stuff' you are trying to relearn can be done (more easily) on a uC. From a learing viewpoint your time might be better used learning to program. The hardware nuts and bolt will come back (or be dredged up) when needed.

Do as you see fit.
3v0

Quote:
Originally Posted by zsh8me2
I attached the schematic in one of my earlier posts. Once I open the board everything is to the left of the enclosed board. I was able to enlarge the board area, but it took me over an hour to find places where I could put the components (about 20 components out 200+ components.
You can increase the size of the box but a trial version will accept components inside the former area only and not beyond, even if the boarder shows more area.
I was asking for a .sch as eagle file not a .pdf version of the schematic. I saw the pdf.

mvs sarma - You are correct on the trial version. I went to their website and actually read what I should have to start with. I was going to buy the standard edition, but it did not increase the board size enough. I don't have $1494 for the pro software, anyway, I have thought of a solution. I will make the entire board using the area that I can use with the Lite Version of EAGLE and cut and paste together, not sure if it will work, but it is easier to try this than to work the overtime to pay for the full version.

I have attached one of the middle sections of my idea. I don't know how practical this will be since i will be using a double sided board. Any suggestions would help greatly.


Thanks


C