On Fri, 2002-09-13 at 11:37, edoc yeknom wrote: > Hi, > I'm a software engineer and have just over 10 years of experience behind me > some of it very low level (device driver and control etc). I have just > joined the list as I am about to embark on a project using a PIC as the brains > behind the thing. I guess you can all see my problem, I do not have very much > hardware knowledge. > I'm hoping to get a PIC up and running and have it flash some LEDs this > weekend and am planning on heading to Radio Shack to pick up components this > afternoon. You probably won't find PIC's there. (GRIN) > Besides the PIC itself and the components to build a programmer I was > wondering if you guys could tell me what other components I should buy > while I'm there? What would make up the perfect beginners electronics tool box? > Also does anyone have any links where I could get a basic grounding in > electronics quickly? ie. I know if I connect an LED to an output on the PIC and > to GND without a resistor I will probably burn out the PIC due to excess > current, but why? and how do I know how much resitance to put between the LED and > GND?? This is one of "those" questions that anyone here will have a difficult time relating directly to the PIC. It's really a basic electronics question. The reason the current will be too high is good old fashioned Ohm's law. The Radio Shack store may have some basic electronics books (I don't know what they carry) and I'll throw another plug in here for Myke Predko's PIC book again, which can be widely found. On the CD-ROM there's a PDF file called "Introduction to Electronics" that appears to be a section that wasn't published in the paper book, but is available digitally on the CD. There are also literally hundreds of online electronics tutorials, some free, or you can buy more "polished" ones from many many vendors. Perhaps some folks can post some of their favorite "new to electronics" websites, I've never gone looking for one really, but I know they're out there! If you just want to tinker, Radio Shack used to sell their own version of little Electronics "fun" kits that had various components all laid out on a board with spring clips and lots of little connection wires and a decent basic electronics book... the whole thing is written for and marketed to kids, but if you're a kid at heart... (GRIN)... Of course there are many other more serious "adult" oriented basic electronics learning kits out there also... and building a few of someone else's designs first and learning to see the similarities between various popular designs always is good experience too if you have no electronics background at all. Finally there are a number of good electronics magazines you can dive into at a really good bookstore or newsstand type store, depending on where you live. Many of the projects will be "over your head" at first, but eventually you'll see something you just HAVE to build and you'll fight your way through it with soldering iron and multimeter in hand... and each one of those done will lead to more knowledge. I'm NOT trying to sound "uppity" here, but going from zero electronics knowledge to having a PIC blinking LED's is going to mean it's going to be a LONG weekend. Grab some stuff and try some things first like a small battery, a resistor and the LED... get that to light... then fiddle with a seven-segment LED display or an LED bar-graph display (both available very cheap at Radio Shack) and a few pushbutton switches.... see how if you turn on all the LED's at the same time the voltage drops a bit... and they're dimmer... fiddle with putting a row of LED's on a breadboard and tying their cathodes together and then lighting them through one resistor... stuff like that. Stick a potentiometer in the circuit... see how you can vary the output of the LED's... Experiment! Have fun! When you get a bit of the math under your belt and have figured out all the various ideas you can come up with for the LED's... then find a schematic (some of the symbols and stuff may be very foreign to ya... depending on how clean the schematic is) of one of the LED blinker projects for PIC's out there and figure out how to wire it up on a breadboard... then without the PIC in the circuit... test it to see if the LED's light when you apply voltage to the pin output line where the PIC will be placed... Then grab a PIC and program it (this can be frustrating if your programmer is not happy for any reason...) and plop it in the circuit that you've copied from a schematic (you'll need on most PIC's an off-board oscillator or crystal and caps, and you'll need to feed power to the chip and to the MCLR line via a resistor... etc... etc... etc... See what happens. You'll have fun! (Oh and finally, make sure to check out the PICLIST FAQ regarding putting topic tags on your e-mails. A lot of people probably didn't see your original post because it had no subject line at all. I've added the [EE] to this, which is about as close as the PICLIST gets to basic electronics topics! (GRIN)) Nate -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu