Crystals & Caps - Super noob question??

[mackrackit]

Simple questions are good. As long as a simple answer is "OK"

1- The internal oscillators are great for some things. Set it up in the config file *.inc and DEFINE OSC ? at the beginning of the PBP program. If you are using the external MCLR setting then the manual is the way. Some PICs can be set with in internal MCLR, if you do this then you can use that pin as an input and it makes ICSP easier.

2- External oscillators are more accurate. If you are doing critical timing such as SERIAL communication then external is needed.

3-4-5- Go with the three pin oscillators ( you are correct, everything in one package ) I use these
http://www.allelectronics.com/cgi-bi...SONATORS_.html
If the crystal is used then the correct capacitors have to be used (found in data sheet) and the part count goes up and all of that. The three pin setup will go in place of the of the crystal in the manual with the outside pins connected to OSC1 and OSC2. the middle pin goes to the ZERO rail (ground).

For good projects with good explanations look at this site. http://www.rentron.com/pic.htm

[RussMartin]

kevj, you didn't mention your general level of electronics knowledge, and it would help us to answer you if you would share that.

Something I always recommend to anyone is: Get some good, fundamental reference books. They don't have to be expensive. You might find it handy to pick up a used copy of Grob Basic Electronics (Bernard Grob) and perhaps Digital Systems (Ronald J. Tocci). If you'd like a little more "meat" (a lot more, actually), you can't go wrong with The Art of Electronics (Horowitz and Hill), harder to find used, and expensive even then, but worth it.

Also, it helps if you tell us what your application is--what you are trying to do at any given point.

All that being said--dive in and have some fun!

Russ

[kevj]

Thanks Dave - that's a big help.

kevj, you didn't mention your general level of electronics knowledge, and it would help us to answer you if you would share that.

I suppose I should have put out some more info.

I've got a pretty good basic knowledge of DC circuits and use of major components - simple stuff with transistors, caps, and simple IC's (like 555 circuits and such). I've also got a good knowledge of programing - my real pro background is in web coding to interface with database back ends - but I've got little experience programming the "tiny computer" that is the PIC. I get ideas of stuff to rig up all the time and I've always wanted to learn to program MCU's, but was always put off by the assembly knowledge - someone finally pointed me to PBP - I knew I could program a BasicSTAMP using "basic" but never realized I could actually program the much faster, smaller, cheaper PIC's using similar methods.


So now I'm just trying to clairify how to actually physically wire up the PIC's for proper operation.


My current application is using timing to read random pulses coming over a radio link. I posted it here:
http://www.picbasic.co.uk/forum/showthread.php?t=6966

That's going to require timers and interrupts. We'll take it one step at a time.


Thanks again for the help and links above - very helpful stuff. I've read the PBP manual cover to cover now and look forward to diving in once my parts arrive this week.

[Cabomba]

Here you can find some very useful information about oscillators: http://techtrain.microchip.com/x14/osc/