View previous topic :: View next topic |
Author |
Message |
SBS
Joined: 15 Aug 2005 Posts: 18
|
Using a PIC on a breadboard... |
Posted: Thu Sep 22, 2005 8:32 am |
|
|
Hi,
I'm about ready to start my project. For my first prototypes, I will be building everything on a breadboard. I remember from my senior project in high school that some teams had issues when trying to put a crystal oscillator on a breadboard. I intend on using a crystal oscillator to clock my PIC.
1) A crystal oscillator is the most common clock source for PIC projects, right?
2) Has anyone had any experience using a crystal oscillator to clock a PIC on a breadboard?
3) Because the oscillator doesn't come in DIP form, I'm planning on just soldering wires to the pins and connecting it to the breadboard. Does this sound OK?
Any comments or suggestions will be greatly appreciated!
Thanks,
Sal |
|
|
SherpaDoug
Joined: 07 Sep 2003 Posts: 1640 Location: Cape Cod Mass USA
|
|
Posted: Thu Sep 22, 2005 8:48 am |
|
|
What do you mean by "breadboard"? I hope you don't mean one of those horrible white plastic tiles with rows of holes and little metal clips for each row! Those stink above audio frequencies and they are not very reliable either.
I use vectorboard and flea clips for things that can afford to be large. For smaller stuff I use double sided PCB stock. I cut pads with an Xacto knife and hook things together with Kynar (wirewrap) wire. I use the backside of the PCB as a groundplane so to ground something just drill a hole. Often I mount DIPs by just glueing them on upside down. Remember the pins are now numbered backwards though!
For the basic PIC and oscillator circuit you can buy prototyping boards from lots of sources. Then just use the above techniques for your special circuitry. _________________ The search for better is endless. Instead simply find very good and get the job done. |
|
|
treitmey
Joined: 23 Jan 2004 Posts: 1094 Location: Appleton,WI USA
|
|
|
newguy
Joined: 24 Jun 2004 Posts: 1909
|
|
Posted: Thu Sep 22, 2005 9:00 am |
|
|
I have to agree with SherpaDoug on this.
The oscillator connections can be tempermental on a proper PCB - on a breadboard? Forget it! |
|
|
SBS
Joined: 15 Aug 2005 Posts: 18
|
Awesome! |
Posted: Thu Sep 22, 2005 9:09 am |
|
|
Great! This is the kind of information that will save me from many hours of headache.
Thanks for the info!
-Sal |
|
|
adrian
Joined: 08 Sep 2003 Posts: 92 Location: Glasgow, UK
|
|
Posted: Thu Sep 22, 2005 9:18 am |
|
|
I am running a 16F913 on Veroboard at 8Mhz. Ok so it's not that fast, but I use the internal oscillator - no external oscillators required. |
|
|
kender
Joined: 09 Aug 2004 Posts: 768 Location: Silicon Valley
|
DIP |
Posted: Thu Sep 22, 2005 9:38 am |
|
|
The standard full- and half-size oscillators will fit on the breadboard as is. There also are oscillators in 8-DIP and 14-DIP, for example SG-531P (you can find them on DigiKey). |
|
|
AK
Joined: 20 Apr 2004 Posts: 33
|
|
Posted: Thu Sep 22, 2005 11:46 am |
|
|
I develop PIC projects all the time with a breadboard with out a problem. As long as you don't have the wires sticking up like giant antenae's you shouldn't have a problem. |
|
|
kender
Joined: 09 Aug 2004 Posts: 768 Location: Silicon Valley
|
|
Posted: Thu Sep 22, 2005 12:07 pm |
|
|
AK wrote: | I develop PIC projects all the time with a breadboard with out a problem. As long as you don't have the wires sticking up like giant antenae's you shouldn't have a problem. |
Same here. I never had problems with oscillators or crystals for PICs. The highest frequency I used was 20MHz, and I always kept the traces as short as possible. The clock input would usually be the only high-frequency signal on your board.
Try it out. It's quick to try. |
|
|
asmallri
Joined: 12 Aug 2004 Posts: 1635 Location: Perth, Australia
|
|
Posted: Thu Sep 22, 2005 2:38 pm |
|
|
AK wrote: | I develop PIC projects all the time with a breadboard with out a problem. As long as you don't have the wires sticking up like giant antenae's you shouldn't have a problem. |
I have used the white breadboards with 20MHz crystal without too much problem. For a short term breadboard project spanning a few days I would consider this method viable. _________________ Regards, Andrew
http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!! |
|
|
StuartH
Joined: 19 Aug 2005 Posts: 14 Location: W. Midlands, UK
|
|
Posted: Fri Sep 23, 2005 6:03 am |
|
|
I've never had any serious problems with solderless breadboards either. In fact, they've saved me a whole heap of development time. I've run many different types of PIC, with clock rates from 1-16MHz (RC,single crystal, oscillator modules and oscillators built with discrete components) without trouble.
As has already been said, they're not intended for long term use - but to prove a circuit they're really useful. |
|
|
JimB
Joined: 25 Aug 2005 Posts: 65 Location: Huntington Beach, CA
|
Quick turnaround, inexpensive PCB |
Posted: Sat Sep 24, 2005 5:12 pm |
|
|
I have used a company called ExpressPCB. For breadboard work this is a great place to investigate. First of all you don't need any fancy PCB layout software, you can download theirs for free. The built in library is quite complete and I found that allmost all surface mount standard packages are supplied. If you just want a quick prototype board and stay under a certain size aand don't want such things as solder mask, silkscreens, etc. you can get this small board back in a couple of days after submitting your design for around $60. (Ithink that is for three copies of the board.)
I personally cannot solder the fine pitch parts myself, so I employ a lady who does this for living for a very modest cost. Order your parts from Digikey and for not a high cost you can have yoursefl a PCB for a very reasonable price. They are going to offer the ability to use Orcad netlists to do the rubberband connects so that all you have to do is draw the circuit. It's definitely worth looking into. I'll bet that Orcad is the most ubiquitous shematic capture around. |
|
|
sseidman
Joined: 14 Mar 2005 Posts: 159
|
Re: Quick turnaround, inexpensive PCB |
Posted: Mon Sep 26, 2005 7:01 am |
|
|
JimB wrote: | If you just want a quick prototype board and stay under a certain size aand don't want such things as solder mask, silkscreens, etc. you can get this small board back in a couple of days after submitting your design for around $60. (Ithink that is for three copies of the board.)
I personally cannot solder the fine pitch parts myself, ... |
There are a variety of companies that offer essestially the same service using standard Gerber files (that is, you can use your own routing software) for about the same price, and they give you all the bells and whistles that ExpressPCB doesn't. You'd have an easier time soldering the fine pitch chips with a solder mask!
That said, I usually breadboard my projects before cutting a board using a kit like the CCD ACE, but regular breadboards seem to work almost as well |
|
|
Mark
Joined: 07 Sep 2003 Posts: 2838 Location: Atlanta, GA
|
|
Posted: Mon Sep 26, 2005 7:05 am |
|
|
I've etched them in the Kitchen sink before in a glass tray of course. |
|
|
ljbeng
Joined: 10 Feb 2004 Posts: 205
|
|
Posted: Mon Sep 26, 2005 7:17 am |
|
|
I just solder the crystal right to the micro pins when I prototype with a bread-board. |
|
|
|