On Sat, Mar 23, 2002 at 02:50:38PM -0700, Shawn Mulligan wrote: > I agree that the 16F84 is an excellent chip to begin with. I disagree. > It comes in a > small package which fits nicely on a prototype board. The 16F628 comes in exactly the same package. >It is very well supported and easy to use. The 16F628 runs everything the 16F84 does with very minor modifications. > Programmers can be built easily by a beginner, > using very few components. By utilizing low voltage programming, even simpler programmers with even fewer components can be built for the 16F628. Other than the fact that the existing 16F84 codebase obviously runs unmodified on 16F84s, there is absolutely no advantage to using a 16F84 over a 16F628. A lot of times begenners tend to focus on the starting line because that's all they've seen. However anyone that sticks with it won't stay a beginner and will start to tackle more challenging projects. The additional hardware support of the 16F628 (USART, PWM, capture/compare, multiple timers, more all around memory) will assist anyone who proceed beyond the basic blinky LED type projects. And it cost less. $6 for the 16F84A-20/P, $3.88 for the 16F628-20/P on Digikey. Can anyone explain to me any advantage of the 16F84 over the 16F628 for a beginner who hasn't purchased parts yet? Other than the sole reason I listed above? I truly think it's a disservice to advocate beginners starting in a smaller box simply due to inertia. Simply put a beginner will have to learn more on a 16F84 to get over the initial hump. Hardware generally simplifies code. Less hardware requires more complex code. Hardware can asyncronously handle tasks without constant code intervention. Software often requires syncrony and polling to keep track. Then it gets complicated by the fact that the 16F84 only has one timer, one puny 8 bit timer. I advocate the better part. BAJ > Realistically, for $50 - $100 you could purchase > a couple of PICs, an LCD, keypad, LED's, support components and a few good > books. I would recommend Easy PIC'n and PIC'n Up the Pace. After you gain > some experience you might try Myke Predko book -- it's excellent to, yet it > may be too advanced for the absolute beginner. With a degree in computer > science, I find some of Myke's algorithms and approaches quite clever, yet > certainly not intuitive. The Easy PIC'n series doesn't attempt to optimize > code size or efficiency at the expense of clarity -- however successfully > manages to present many interesting projects and tutorials. That's my two > cents worth. > Shawn > > > >From: Pic Dude > >Reply-To: pic microcontroller discussion list > >To: PICLIST@MITVMA.MIT.EDU > >Subject: Re: [PIC]: Please help rookie with these two questions > >Date: Sat, 23 Mar 2002 15:31:31 -0600 > > > >A slightly different perspective... > > > >As a rookie myself, I believe that the 16F84 is a great chip to > >start with, because there are lots of sample projects/code out on > >the web to pick things up quickly. You can just copy, compile > >and test, then experiment with the code. At a few bucks each, > >cost isn't much of a factor. > > > >And if they're becoming obsolete, then perhaps they're less > >than a few bucks now? > > > >Get a very simple 16F84 programmer or get one that will handle > >16F84 + others you think you will need. I built a simple Tait > >programmer and there was a simple wiring difference to handle > >the 16F872's when I started playing with those. > > > >Good beginning info and books... > > http://www.piclist.com/techref/piclist/begin.htm > > > >Cheers, > >-Neil. > > > > > >----- Original Message ----- > >From: "Byron A Jeff" > >To: > >Sent: Saturday, March 23, 2002 2:23 PM > >Subject: Re: [PIC]: Please help rookie with these two questions > > > > > > > On Sat, Mar 23, 2002 at 02:01:45PM -0500, Jim Martin wrote: > > > > First: What beginner's book do you recommend for entry level PIC > > > > programming for the 16F84? > > > > > > It's best to skip the 16F84. Microchip has pretty much succeeded in > >obsoleting > > > it with the features and price of the 16F627 and 16F628 chips. It's > >better > > > to start there. > > > > > > I don't have a book recommendation for you unfortunately. There are any > >number > > > of online tutorials that'll get you started. I'm partial to Myke > >Predko's > > > online stuff. You can find a couple of introductory articles here: > > > > > > http://www.rentron.com/Myke3.htm > > > http://www.rentron.com/Myke5.htm > > > > > > There are also several dozen other PIC related articles on the site > >here: > > > > > > http://www.rentron.com/pic.htm > > > > > > I'd like to add a couple of comments related to the 16F84 to 16F627/8 > >upgrade. > > > First is that if the application isn't time sensitive (such as an > >asyncronous > > > serial interface) that the internal RC oscillator of the 16F627/8 > >preludes > > > having to use an external oscillator or resonator. Next is that one must > >be > > > acutely aware that one of the best new features of the 16F627/8 is the > >onboard > > > hardware USART. This means that one doesn't have to implement software > >UARTs > > > by hand. I find that a lot of 16F84 tutorials spend a lot of time > >discussing > > > how to build software serial routines for RS-232. The next thing is that > > > the 16F627/8 family along with the 16F87X family are low voltage > >programmable > > > so very cheap and simple programmers can be utilized to get started > >quickly. > > > My Trivial Low Voltage Programmer (TLVP) is a $10, afternoon project > >that'll > > > get you in the game quickly. Last on my list is that for programming > >hardware > > > USART the best software/tutorial going is Fr. Thomas McGahee's PICUART > >code. > > > I've seen problems dowloading it from his site > >(http://mcgahee.freeservers.com) > > > so I've made a copy available from my PIC site where the TLVP lives: > > > > > > http://www.finitesite.com/d3jsys > > > > > > Also you can find a description os Myke's book "Programming and > >Customizing > > > PICmicro Microcontrollers" on his site at http://www.myke.com where he > >has > > > a online chapter for your perusal. > > > > > > > > > > > Second: Is the 16F876 code-compatible with the 16F84? Just wondering > >if I > > > > should start with the '876 instead of the F84. > > > > > > I think you can pretty much get a consensus not to start with the 16F84. > >Yes > > > the 16F87X series is code compatible with the 16F84 and will port over > >with > > > a very few caveats such as variable starting address and that PORTA > >starts > > > in analog mode instead of digital mode. > > > > > > But starting with the 16F84 means playing catchup later. There's much > >less > >of > > > a jump from the 16F62X family to the 16F87X chips. > > > > > > Hope this gives you some insight. > > > > > > BAJ > > > > > > -- > > > http://www.piclist.com hint: PICList Posts must start with ONE topic: > > > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > > > > > > > > > > > >-- > >http://www.piclist.com hint: PICList Posts must start with ONE topic: > >[PIC]:,[SX]:,[AVR]: ->uP ONLY! 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