Hi there

I am new to the forums. At age 16, just getting back into electronics after trying to do too much too soon with not enough understanding a few years earlier. One of the things I am having a go at is PIC development, something which completely stumped me 'back then' as I've been using Mac OS for years, which is pretty much devoid of PIC development tools!

Anyway, I think I've found my way around that. However, I have found that I am having to request free samples of randomly picked PICs - there are a vast amount, and the microchip website is rather unfriendly, if helpful. Is there, somewhere, a clean, friendly list of popular/useful PIC models, allowing easy comparison and filtering?

And if there is not, would it be useful to have one built? I am a fairly competent web developer — how about a community-driven, friendly, filtrable index of PIC models?

Thanks a lot, looking forward to learning from this forum (and perhaps even imparting what little knowledge I have )

Barnaby

 

Here's a couple of useful pages:
http://www.microchip.com/maps/microcontroller.aspx
http://www.microchip.com/productselector/MCUProductSelector.html

 

The big unknown is whether you know any programming languages. I didn't when I started with PIC's a few years ago, so I started with Assembly, rather then trying to learn a language like C and PIC's at the same time. There are lots of tutorials in Assembly too.

That said, for Assembly, I like the 12F5xx (e.g., 12F509) series for simplicity. The 12F6xx (e.g., 12F683) series is very similar, but adds analog input functions. The 12Fxxx's are small and cheap too. The 16F628a was a good learner, but I believe it has been supplanted by a newer 16Fxxx chip, like the 16F88 or 16F87x (not sure on that).

John

 

Hi, Barnaby; welcome to the forum!

I too just got started using some PIC processors. I was fortunate in that a friend from across the country visited last week and he ordered a bunch of PIC stuff for us to play with.

Based on my experiences last week, the easiest way for you to get going is to purchase the PICkit 2 Starter Kit for $50. Now that may sound like too much money for a starving student, but consider it an expense like a textbook.

Once you have that, you'll also need a Windows XP or later machine to run the software on; the software is called MPLAB and is an IDE (integrated development environment) that lets you assemble/compile your code and download it to the processor. If you can't work on a Windows system, then I doubt any of this stuff is usable, although you might be able to find some suitable cross compiler.

The attached picture shows the PICkit 2 and the small PC board that comes in the package. It includes a PIC16F690 18-pin processor. This is a mid-range processor that costs a few dollars and is suitable for a number of simpler applications. Most importantly, a CD includes lessons that will get you up to speed on programming these chips. You learn how to blink the LEDs, debounce the switch, and use analog inputs to measure the voltage on the pot wiper.

You can also get a PICkit 3 and a development board, but I suspect most hobbyists would want to start off learning to use the smaller processors first. If you had $125 to spend, I'd strongly recommend the PICDEM Lab, as it has more sockets for processors and a nice prototyping area, along with a number of parts to help you experiment. While this sounds expensive, you literally dump the stuff out of the box, connect things up, install the software, and start working. This saves a lot of time over collecting everything yourself.

Once you have digested the lessons in these kits, you'll be in a much better position to decide what chips you want. Basically, the problem you're trying to solve (i.e., its design constraints) will determine which chips are suitable.

 

I would recommend a good PIC emulator to start with.
You can then play to your hearts content without having to plug/unplug pics from circuits.

I used to work for a PIC consultancy for 13 years and we used emulators to speed up development.

These days I just use a PICSTART Plus as i have loads of old PIC programs to draw on.

The PIC16F510 is a great little start pic. I have used it for SMPS.

 

I agree with Someonesdad--the PIC16F690 is a very nice chip. Doesn't cost much, loads of features.

 

First of all what is your budget. In any cases I would recommend a PICKIT 3 debug express. And for development use MPLAB. I would also recommend jumping direct to PIC18F series and using a Compiler. You can find free versions of C compilers that will integrate well into MPLAB. And also invest in a proper breadboard.
The reason for recommending a 18F series chips. Is mostly the fact that all 18F series support hardware debugging directly from the PICKIT 3. No need for anything extra.
I suggest you find some options that fit your budget. Then present them here for comments. I am sure we can find something.
But a PICKIT 2 or 3 is imperative for your success

 

I'd recommend the 18F1320, it's the advanced 16F84 of the modern age. It's actually easier to program than the 16 series and inexpensive. I designed the Junebug PIC tutor kit around it.

 

Lots of good suggestions and ideas. There are many routes to success. I agree with Nigel that the emulator is a good thing to help you test out programs. Still, us hobbyists like to see blinkin' lights on the board. That's why I recommended the PICkit 2 starter kit or the PICDEM Lab kit -- you'll be up and running in no time.

I also agree with the suggestion of using a C compiler, as I prefer to use C over assembly because assembly knowledge isn't portable. However, when you're starting to learn the PIC, you'll want to run through the basic lessons in assembly because learning the mnemonics helps you learn the chip's architecture. This is important, especially when you want to look at the assembly the compiler dumped out later and make sense of it.

I second t06afre's advice about needing a PICkit 2 or 3. I think it's important not to waste your time on building such things yourself (the EEVblog has similar advice) even if you can. I also recommended the PICkit 2 Starter Kit or PICDEM Lab because they come with sockets for DIP chips. That suits me better than trying to muck around with surface mount stuff with my geezer eyes and palsied brain...

 

Woah! Lots of replies. Thank you very much!

I'm familiar with several programming languages, and I'll be working in assembly to begin with, at least. I've run a few tutorial programs in the MPLAB simulator, watching how they work, and I've got a decent understanding now. Also been learning about binary arithmetic!

I'm going to be doing the development in MPLAB, running under Wine on Mac OS X. I'll then be using a usbpicprog (€20, In circuit programmer, supports tonnes of pics and works with OS X) to load the hex onto the PICs. So far, I've been choosing the PICs to get free samples of from the list of supported models! I may try out a microchip programmer/debugger/emulator, but at the moment I have no guarantee that would work (with MPLab running under an emulator), so I'll only give that a go when I need advanced emulation abilities, I think.

Someone mentioned investing in a quality breadboard — what type would you recommend? I currently have a cheap one, and the low cost is starting to show. Some holes are becoming unreliable.

Just thought I'd mention — the PICs I have requested free samples of are the 18F452 (Big, lots of confusing features and config options!), the 12F615 and 16F684 — so I have a range of sizes and abilities.

Thanks a lot for your help,
Barnaby

 

Should have asked for the 18F4620 as the 452 needs an external oscillator.

 

Should have asked for the 18F4620 as the 452 needs an external oscillator.

Oops, my bad — I did order the 18F4620. I made sure it had an internal oscillator, I didn't want to faff around with crystals on my first try.

Thanks,
Barnaby

 

Good idea. Now never neglect your 0.1uF bypass caps.

 

Also take a look at Swordfish BASIC SE (limited free edition) an excellent PIC 18 compiler.

 

Ok, showing my ignorance now — what are bypass caps and where should I be putting them? Are they across the power lines?

 

Yes, they should be across the power pins of all digital ICs.
http://hackaday.com/2008/09/29/parts-01uf-decoupling-capacitors/

 

Ok, showing my ignorance now — what are bypass caps and where should I be putting them? Are they across the power lines?

Have you read this?
http://forum.allaboutcircuits.com/showthread.php?t=45583

 

So true, they are neglected often by students that did all their work in software simulators. They build the PCB just to find it wont work because they didn't sprinkle a few 0.1uF or power supply caps (the larger ones) on their layout.

 

Woah! Lots of replies.
I'm going to be doing the development in MPLAB, running under Wine on Mac OS X. I'll then be using a usbpicprog (€20, In circuit programmer, supports tonnes of pics and works with OS X)

NO NO NO Get a PICKIT. You can NOT do hardware debug with programmer. If you are a on a budget pick up PICKIT 2. If not put in the extra money and get a PICKIT 3. You will sooner or later regret that you first wasted money on the usbpicprog in the first place
Also a new version of MPLAB with support for several OS will soon be released. It is named MPLAB X. http://ww1.microchip.com/downloads/mplab/X_Beta/index.html

 

NO NO NO Get a PICKIT. You can NOT do hardware debug with programmer. If you are a on a budget pick up PICKIT 2. If not put in the extra money and get a PICKIT 3. You will sooner or later regret that you first wasted money on the usbpicprog in the first place
Also a new version of MPLAB with support for several OS will soon be released. It is named MPLAB X. http://ww1.microchip.com/downloads/mplab/X_Beta/index.html

Thanks for the advice, I haven't bought anything yet, and am still considering a PICKIT of some form. The problem is, I really have no way of telling whether it will work or not! Wine is a great emulator, but I'm not sure how well it handles communication with proprietary USB devices. Is hardware debugging as useful as it sounds?

I have tried out the beta of MPLab X and was quite unimpressed… as far as I am concerned it's pretty nasty . I really don't like the way it works — and it works very badly on my computer, at least. Then again, it is still in beta, so it may have improved before it launches.

Thanks a lot,
Barnaby