Search found 8 matches

by Ron Hayes
Sun Aug 10, 2003 10:34 am
Forum: General Discussion
Topic: resistor problem on uC
Replies: 2
Views: 894

resistor problem on uC

I'm using a resistor pack to hold portb of my uC low but when I send one pin high the whole port is going high, it's a 20K RP, it worked just fine in the breadboard but now that it's in the PCB i'm getting problems.<p>Any ideas??<p>Ron
by Ron Hayes
Mon Jul 07, 2003 5:53 pm
Forum: General Discussion
Topic: Crystal won't start
Replies: 2
Views: 1026

Crystal won't start

I'm having a problem with a circuit I've made, it worked fine on the breadboard and now that it has moved to a PCB the crystal won't start I just get 5V and no Oscillation, now I know it's hard to guess at the problem without seeing the PCB but I traced it out and it is fine, I even removed the Caps...
by Ron Hayes
Thu Mar 13, 2003 3:24 pm
Forum: General Discussion
Topic: Creating Custom printed PC Boards
Replies: 20
Views: 4762

Re: Creating Custom printed PC Boards

Here is how I make mine (I use a laser printer but you can do this with an injet as well just different transparencies) make your PCB on the computer, print it on the transparency, using photosensitive copper clad board you place the transparency on top of the board (in very low light and ink side d...
by Ron Hayes
Wed Mar 12, 2003 8:38 pm
Forum: General Discussion
Topic: Double sided PCB's
Replies: 5
Views: 1389

Re: Double sided PCB's

Hmm that sound easy, won't there be a bit of distortion due to the thickness though? I should give that one a try though on a small test board to see how well it works!<p>Thanks
Ron
by Ron Hayes
Tue Mar 11, 2003 2:33 pm
Forum: General Discussion
Topic: Double sided PCB's
Replies: 5
Views: 1389

Double sided PCB's

I've been making single sided PCB's for a while now using pre sensitized board, now I have a much more complicated board to create and I think I need to use double sided board, I just like to get some tips from those of you that have done this and can pass along a few hints as far a lining up the tw...
by Ron Hayes
Thu Feb 13, 2003 3:05 pm
Forum: General Discussion
Topic: Creating a high impedence probe
Replies: 6
Views: 1886

Re: Creating a high impedence probe

Thanks for all of your help<p>I used a 74LS244 and it's working like a charm, the probram that I', using was written in ASM and is fairly fast, I'm not too concerened about realtime being in windows I never expected that, I just wanted to see the relationship between the lines. I'm running a P3/733 ...
by Ron Hayes
Wed Feb 12, 2003 8:25 pm
Forum: General Discussion
Topic: Creating a high impedence probe
Replies: 6
Views: 1886

Re: Creating a high impedence probe

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by Russ Kincaid: Since you are using the parallel port, you must be looking at logic signals. The solution is to use CMOS logic buffer such as 74AC244 or 74HC244. <hr></blockquote><p>I actually did th...
by Ron Hayes
Wed Feb 12, 2003 3:51 pm
Forum: General Discussion
Topic: Creating a high impedence probe
Replies: 6
Views: 1886

Creating a high impedence probe

Hello, I'm trying to make a logic analyzer using my parallel port but I don't want to load down the target circuit, what would be the best way to do this?
My first thought would be to use a MOSFET since they have a high input resistance.<p>Any ideas?<p>RonH