robotics newbie: PIC microcontrollers

Do you have any design tools? Search for compilers, assemblers, programmers,debuggers; some of them will not work with all PIC controllers.

Search for code. Reading other peoples code will give you an idea of what you can do with various chips. Even if you don't reuse their code, it's a starting point for ideas.

is a good start.

What is selling? Check out

and others. They don't sell a large variety, so maybe what they do sell is something that most people can use.

Search the robot sites for PICs; see what robot builders are using.

Search microchip.com for "nanowatt" microcontrollers. They are extreme lowpower chips. You might want to look at these chips for battery-powered use. While you are there, search for low power application notes.

Have fun!

Do not forget Atmel's AVR

Pic is an older thinking of processors architecture. 70's. Avr's newer 90's.

All with flash memory, all with 32 accumulators (great for C or Basic), allmost same set of instructions from the smallest to the bigest one. So when working in assembler u do not have to learn something new.( pic line changes)

And most of it: Working in assembler u do not have to change memory banks.(like pic is) Very easy to learn.

Programmer is cheap (0-10$)

Free evaluation C or Basic compilers (Codevision, Bascom (2 K of Code)). If u want to buy them they are in a range of 100-200$.

1 cycle/instruction (so 1 MHz =1 mip). For microchip is 4 cycles per instruction.. so 4 Mhz=1 mips

Check:

(all kind of AVR or Microchip - very good site) (support) (for cheap programmers AVR or Pic) they are makeing also PCB's very cheap. I've done it and it is working very well

Good luck Eugen

I've gotten samples from AVR reps.

DLC

:> Do not forget Atmel's AVR :>

:> Pic is an older thinking of processors architecture. 70's. :> Avr's newer 90's. :>

: Yeah, of course. I'm agree with you, but.... They don't send samples??.

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Nitron wrote: Well,

I do have a business that uses embedded processors, I do consulting.

DLC

: Maybe, but you must be good lying(or be a lawyer) and have 10.000 units : waiting for that samples.

:> I've gotten samples from AVR reps. :>

:> DLC :>

:> :> Do not forget Atmel's AVR :> :>

:> :> Pic is an older thinking of processors architecture. 70's. :> :> Avr's newer 90's. :> :>

:> : Yeah, of course. I'm agree with you, but.... They don't send samples??. :>

:>

:>

:>

:> -- :>

: ============================================================================ :> * Dennis Clark snipped-for-privacy@frii.com

: * :> * "Programming and Customizing the OOPic Microcontroller" Mcgraw-Hill 2003 : * :>

: ============================================================================

Dennis,

Well, me too, I'm expert on robotic, ITS applications and intelligent control, but I live in Chile, southamerica.

All Semiconductors Company send samples to Chile, but Atmel. Nope. Not even having an address in Miami.

They first call you and ask you: Why do you want our chips?. Are you a terrorist?. Did you build a bomb?. Are you a human being?.

That kind of questions makes you forget Atmel until they have a better commercial policy, like Microchip.

Microchip uC are poor, an inefficient and old arquitecture, but they send you samples for free, development kits, low cost C compilers, almost free programmers.

Well, bye bye Atmel, or until they send samples, or when I apply on Circuit Cellar-Atmel contest. I'm sure they send a little sample for the contest.

Best regards, Rodrigo Arriagada - Nitr> Well,

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"Refik Hadzialic" wrote in message news:...

Heck yeah! Free Samples! I just got some PIC16F88's for free! I love you Microchip! Too bad I'm just learning so I'm gonna stick with the PIC16F84/84A to get my feet wet, because that's what I can find lots of info on on the web. You're kind of left on your own with the PIC16F88 because it's so new (July 2003.)

So, if you wanna get started, for cheap, and don't mind soldering a kit together - me I love soldering kits! - then in the USA I recommend either Carl Electronic Kits (electronicskits.com) or Amazon Electronics (electronics123.com) kit #81. It's 15.95 for the kit, but they get you on the 4.95 shipping = 21 bux. This kit is actually produced by kitsrus.com in Hong Kong and sold all over the world by kit resellers, so you pretty much get the same thing from all of them. The nice thing about this kit is that it also has a test circuit already for you, to move the chip over to the test socket and flash leds. It's ideal for learning. Read about it here:

you add up all the cost - a $5 PIC16F84A from digikey+shipping, 3 dollars for a perforated protoboard from radio shack, if they stock it at all, plus resistors, diode bridge, capacitors, the correct voltage regulators, plus the time you put into making the board and in the end you might end up with something that doesn't even work and wonder. So the nice part is, that if you don't want to spend 200 bux for a professional programmer just yet but you still want something that's guaranteed to work to get your feet wet now, and then you want to either get bolder later and construct programmers on your own, or shell out the big bux once you know what you really want, then this is the one for you for now. The downsides are that this kit 81 is a parallel port programmer (so you have to unplug your printer each time), plus it is meant to do only the PIC16F84 chip by the manufacturer - but you can download the PICALLW software and run it in p16pro shareware mode (25 bux registration fee), and it's supposed to program other 18 pin chips too. But there is no PIC16F88 yet showing in the PICALLW options - does anyone have a custom device.ini that enables the PIC16F88 in the PICALLW software? I'd rather learn on the F88 chip, cuz it has A/D plus serial UART, so I could play with pot-meters and issue commands into a test circuit right from the serial port via VB programs using MSCOMM32.ocx to make it flash leds and stuff. Hey kitsrus.com, how about such a toy? But there is soo much info on the web on the PIC16F84, and almost none on the 88, so I think the 84 is the one to choose to get started with for now, and then move over to other microchip chips. Atmel is losing out big because they aren't nice to the customer even if they have a superior chip according to some gurus. And that also means less hobby info on AVR's on the web. I mean, how much does it cost Microchip to send people a few samples? It surely costs them less than a full blown ad campaign, and it's more effective at getting people hooked. It's just like drug dealers, you get free samples at start, but Microchip does it for a good cause. It's just good business practice to keep the hobbyists well fed with your scrap material. Plus MPLAB IDE is niiiice, and FREE. It's my first time dealing with assembler programming, I've only done C/C++/Java/Javascript/Basic/VB/Perl/PHP/SQL stuff in the past, all high level languages, and the actual workings of the cpu have been sort of a mystery to me. Now I get to manipulate the registers! There is an awesome Mike's Cybot the_pic_tutorial.pdf file floating on the web to get you started with assembler. Plus assembler is the kewlest thing anyway when you're dealing with 2KB of memory plus really simple apps. Atmel does provide a free IDE too, plus, unlike for the PIC's, I think even the C or Basic compilers are free for the AVR's - but no chip samples. That's why Microchip is the top microcontroller seller, rumor is they even topped Motorola just recently. The impression I've got is that Motorola's stuff is really high tech, and better for special applications, but also very expensive, so who needs it? We love these 3 bux mini-computers that can fit inside a box. For a hobbyist the other option is to tie up an old laptop if you wanna do home automation things - what a waste of a laptop and energy resources spinning that harddrive up and down. Talk about nanowatt instead with PIC's! (The F88 chip is nanowatt.) But please don't abuse the sample programs. Order what you need, to get started, and preferably order many chips at once, then don't bother them for a long while. I think they let you have an order every

3 months anyway. It probably costs more to pick and ship the orders than the chips themselves. So don't abuse the sample program or they might suspend it. Glitchbusters.com has PIC's very cheap, so once you're done learning, it's best to buy the chips. Come on it's a few bucks only! I feel it's honest to request samples when you're about to learn - since you're allowing them to get you hooked on their stuff. BTW microchip isn't the only free sample provider - Maxim Dallas has an awesome 12 bit thermometer on a chip 1 wire device - DS18B20, that's quite accurate (0.5C), and can be calibrated to 0.1C accuracy if you have platinum temperature standards - don't we all have one? Just kidding, 0.5C accuracy is good enough for me as long as long as I get that 0.0625C relative resolution - i.e. it tells mewhether the temp is going up or down, it just might be off by 0.5C for all the values, but oh well. The DS18B20 is like 3.50 a piece + 1.25 S/H on the web, so you could sprinkle a few dozen of these sensors all over the place and collect data, on the cheap :). For info, search the web on DS1820 or DS18S20 - 9 bit because there might be more stuff on those. I haven't got far yet, I just started with this microcontrollin' thing a few weeks ago too, got my programmer assembled, and these day's I'm absorbing the tutorials on things like interrupts and watchdog timers. The temperature stuff is for later. But from what I gather the multiwire DS1621/DS1631 can be directly driven from the computer ports via VB, while the 1 wire DS18B20 has critical timing issues, so it needs a PIC16F84 "arbiter" with a crystal oscillator to get the timings right, or a real time OS like DOS. But Maxim-Dallas provides a 1-wire API that works almost straight to the chip, through a com-port, so it seems it's still possible to do the timings okay straight from the computer, as long as you use the 1-wire api dll's that also have some com-port calibrating thingie. And there is a finnish site giving you instructions how to built an extremely simple DS9097E adapter that allows you to work with the dallas software alone, in parasitic mode - no external power needed, stealing power from the serial ports. Search for MLOG TLOG on the web that are DOS only programs, then click on windows thermometer, then adapter schematics. By the way phanderson.com has some nice temperature kits all done for you. I also bought some sensors from them, because I thought maxim-dallas would take 3 months to deliver a sample, but it got here in less than a week. The more DS18B20 sensors the better!

-> heheheh this one was a good :)

-> > > Do not forget Atmel's AVR

-> > >

-> > > Pic is an older thinking of processors architecture. 70's.

-> > > Avr's newer 90's.

-> > >

-> > Yeah, of course. I'm agree with you, but.... They don't send samples¡¡.

-> >

-> >

-> >

-Heck yeah! Free Samples! I just got some PIC16F88's for free! I love

-you Microchip! Too bad I'm just learning so I'm gonna stick with the

-PIC16F84/84A to get my feet wet, because that's what I can find lots

-of info on on the web. You're kind of left on your own with the

-PIC16F88 because it's so new (July 2003.)

I would advise against that idea. Here's the issue: the 16F84 is not only limited in its memory capacity, it's also limited in the periperals that come with it. So what ends up happening is that in lots of the posted projects, the authors end up having to have somewhat convoluted workarounds. Just a couple of simple examples: the 16F84 has only 1 8 bit timer. That means that code that is required to time more than one thing will be more complex because there's only 1 timer. The 16F88, like all the upper range pics, has 3 timers, including a 16 bit timer1. It'll simplify the code.

Software UARTS vs. hardware UARTS is another example. With a 16F84, you have to do a software UART because there's no other choice. However with the upper range chips, the hardware USART is standard.

The list goes on and on. PWM, I2C, self programmable memory, and the like.

Also there is a bunch of code for all of these items though the 16F88 is new. Microchip reuses the same periperals with the same register sets. That means that older 16F877 code for the timers, USART, PWM, CCP, I2C, and the like work fine for the newer chips. The 16F88 is only sightly more that a 16F877 in a

18 pin package. So all of the code geared for that midrange set of chips will transport very easily. Just have a copy of the PIC midrange manual handy and it goes into great detail (along with code examples) of all of the hardware.

While I not saying that a novice is obligated to use everything from the jump, I just think that it's better to start with the chip with everything because as you progress the tools you need will already be there and the mindset to use them will grow with that progress. Plus the newer parts are always cheaper.

BAJ

The 'F84 is a good device for learning to program PICs, but you'll find that you rapidly run out of code space - however, the code you wrote will later be usable on the 'F88. In addition, the 'F88 has a lot of peripherals [timers, A/D, etc] that don't exist on the 'F84, but which are compatible with those on all the other 2nd generation PIC chips, like the 'F76 and 'F77. So, it will be easy to migrate to an even larger chip later on. One step at a time.

- dan michaels

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