Learning PIC - where to start?

First, I'd like to thank everyone for their advice and comments.

For now, I'll get the PICkit2 starter kit. As for more involved demo boards, I'll cross that bridge when I get to it.

want

Well, the MAX can do everything including clean out the kitchen sink, but try to *get* one! Availability of Maxim parts in general has been zilch or less; many disties dropped the Maxim line because they found it impossible to satisfy their customers. Due to that continuing history, i do not even bother to look at the blah blah numbers; i am tuned out at the mention of Maxim (SPAM filter full on). Mention *any* other brand, *please* !

most havs a max-232 or other 5v to RS232 interface chip in them but the +10V these chips produice is not enough for programming the pic.

want

max-232 unlike other maxim parts asily had, and also avalable from TI.

Not necessarily. The native USB programmer needs some sort of processor on-board to handle the USB comms. In principle, this controller can be simpler and cheaper on the RS-232 version, since RS-232 is *much* simpler to handle than USB.

The Wisp648 does work with a USB to serial adapter and it is quite reasonably priced. You can even order it as a kit if economy is a concern. Are there any native USB programmers in the same price segment?

Or at least make sure you buy a programmer *will* work with a USB adapter.

Exactly. The very simplest programmers use bit-banging to implement the programming protocol. Most, if not all, USB adapters don't work with these programmers. I can see three major reasons for this:

1. The voltage output of the adapter may be too low. This probably varies between different makes and models.
2. The drivers for the adapter may be unable to support the low-level bit-banging that the programming software uses.
3. The timing overhead caused by the USB conversion may cause the programming to fail. It may be possible to overcome this by programming extremely slowly, but I have never tried.

--
RoRo

You are happy with breadboarding stuff?

If so add a few DIL packaged PICs that support using the PICKIT2 as a debugger to your order.

PIC16F88 - fits in a PIC16F84 socket and once you've turned off the new ADC converter inputs, its fairly close to being code compatible (You need to set two config words instead of one, User RAM starts at 0x20 not

0x0C and the internal data EEPROM is accessed via different port addresses.) Its got a pretty comprehensive set of mid-range peripherals built in. Better than a PIC16F628A because it has debug support!

PIC16F886 - 28 pin 0.3" DIL package available. Pretty much the same as the PIC16F887 but fewer pins so more breadboard friendly. Debug support.

PIC16F887 40 pin 0.6" DIL package. Same chip as the SMD one on the Debug Express board, but breadboardable.

If you have *any* interest in RS232 stuff make up a converter module with a MAX232 or equivalent with a 9 pin D connector PC side and a 6 pin header to plug into the breadboard. Pin 2 of the MAX232 outputs about

+10V and 'spare' handshake output lines like DSR should be tied high to that via a 4.7K resistor. the MAX232 will convert RxD, TxD, RTS and CTS to/from TTL inverted levels as required by the PIC UART. I've got bicolour LEDs with 8.2K series resistors on those lines on the PC side so that RED is line idle (SPACE) or handshake blocking and GREEN is active data or handshake good (MARK). For testing, loop the TTL level signals till you get successful echo. You can always leave the RTS and CTS looped for no handshaking until you have basic success with the PIC UART.

You will also need a 6 pin header, 6 individual wirewrap pins, some thin heatshrink and 9" of 6 core small stranded cable preferably with a simple primary colour code that gives you a black and a red wire and has all the others easily distinguishable. An offcut of alarm cable is perfect. These bits are to make up an ICSP cable to go from the breadboard to the PICKIT 2. Don't make it longer than 9" or you may get trouble with noise pickup.

Lastly, if using external power, be ****ing careful of ground loops and power sequencing or you risk frying the PICKIT 2. The 'brains' are a PIC18F2550-I/SO so if you are really accident prone, get one, temporarily patch it to a 6 pin ICSP header 'dead bug' fashion using some kynar or magnet wire and flash it with the PICKIT 2 firmware (PK2V0nnnnn.hex from your PICKIT 2 program directory) so you have a spare *before* you blow it up!

--
Ian Malcolm.   London, ENGLAND.  (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
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Snip

Good point Stephen.

Subject: "Learning PIC - where to start?"

Here:

Hope This Helps! Rich

The PIC is made by Arizona Microchip not Atmel - never mind, have another bottle of whiskey.

Rich is a stone-sober pothead ;-)

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

| 1962 | With all this hope and change, all you need is a dab of mayonaisse and you'll have a tasty lunch on which you will choke to death.

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

It must be true what they say about skunk-weed.

No, the point is that the best way to learn about pic is to forget about the PIC and learn about a proper processor, at which point you'll know better.

Cheers! Rich

No, I'm a pot-sober stonehead! ;-P

I see that both of you have been totally overflown by my sardinic tone here, and leapt to ad hominem, as is your wont.

Thanks for once again showing your true stripe, Rich

Odd for an improper processor it seems to be pretty popular. Comparing stock and availability at distributors PIC's blow all of them away. So this must mean your view is in the minority, albeit vocal which is typical.

If you are heading to Atmel anyway, why 8051 instead of Avr?

should be: "no longer even sold at the time"

(spell checker and my too-quick acceptance.)

Jon

A real craftsman uses tools appropriate for the application and works to expand the scope/range of those tools and necessary experiences with them, so as to be better able to bring more options to the table for clients.

To be proud of being limited is what struck me funny about your comment above It reminded me of an phrase I once heard -- "To a man with a chainsaw, everything looks like a tree."

Jon

Wow! Tons of truisms, irrelevant BS and personal insults. This is how zealots defend their beliefs. I used to think we talk about the technology.

"It is dangerous to separate tiger cub from his mother, and a man from his delusions" (c) LaRochefocault (or Kipling ?)

OK, I have to return back to work now. Just another ~20k lines project. For AVR, BTW. Enjoy your Sunday :)

Vladimir Vassilevsky DSP and Mixed Signal Design Consultant

And to a man with a hammer, everything looks like a thumb :)

I'll just throw in my own opinion that the Microchip family seems a good place for someone like the OP to start. My earliest projects were with the

8085 and then the Z80, which I really liked, and then we made a product with a Z-world SmartCore which uses a Z180. The earliest projects were all assembly language, and the newer ones used various amounts of C.

I also used some Signetics PLDs for fairly simple applications, but for some more recent projects a microcontroller seemed more appropriate. At that time (about 10 years ago) I looked at such things as the Basic Stamp, and eventually decided to try the Microchip PIC16C63. It was difficult to learn, especially with respect to bank switching and Read/Modify/Write problems, but I found their tech support very helpful, and their parts suited my needs at the time. I invested a lot of time and money learning their products, and that is probably the main reason I did not really consider using other parts. My projects are very low volume, so the development effort is a major part of the cost, and the cost of the ICs are just about insignificant.

It would be helpful for anyone considering the Microchip products to read their forums at

where you can learn from the experiences of others, as well as receive timely advice from many experts. I'm sure other companies have similar discussions, and each product family has its own quirks, which are often disclosed more candidly in forums than on corporate data sheets and errata.

Also I would like to praise Microchip for their lifetime support of their development tools, which they have replaced even when damaged by my own fault. They have been good about samples, too, but recently they are charging about $8.00 per order for handling and shipping, so sometimes it is more expedient to just order a few parts from Mouser or Digi-Key. I also have enjoyed two of the Microchip MASTERs conferences in Arizona, where you get intensive hands-on training in classes that are tailored to your specific needs or interests.

Paul