why all these 16F84As?

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philba

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This chip is ancient, costs a lot more than the 628A (around twice) and is a lot slower. So why is it that there seem to be so many students using it? I presume they are students as the projects all seem to be student type. Is it because ciriculums set up 10 years ago haven't been changed?
 
It's not just students... When I stumbled onto PIC examples on the Internet for the first time a couple years ago, guess what PIC was used in so many of those examples? Yep, the venerable old 16F84...

If I had just stumbled upon Nigel's site befor purchasing that 16F84 from Digikey I guess I could have saved a dollar or so (grin)...

Regards, Mike
 
Why NOT the 16F84?

Because it is:

1. still relevant as a teaching aid. Lots of training courses use it as an example of the typical embedded microprocessor.

2. there is truck loads of code out there for it.

3. still readilly available.

4. more than capable of handling simple processor jobs.

5. is familiar and comfortable to work with for a LOT of designers.

After taking a shower standing on two legs for 47 years, I have no hankering to try it standing on my head. The 16F84 still does the job. A lot of junk boxes have one or more waiting to go into service again.

Of course, if you're talking commercial concerns, it stinks. Too expensive, too limited. There's lots better chips out now that are cheaper.

End two cents.
kenjj
 
My guess is that it had so much going for it in the past that it became the
best place for beginners to start. With this said there must have been
thousands and thousands of people writing beginner subjects and
examples dedaced to this one PIC. Maybe more than any other in the
past.


Gordon
 
I would agree with you on all counts, except as you know, there are DIRECT DROP IN replacements, such as the '628 which are more capable, faster, and cheaper. Any code changes are hardly worth mentioning. I think the reason Microchip charges more for them is that they are trying to discourage the use of the '84 - they dislike making them as much as we dislike using them! I confess that I have a couple of 'em though...

I suspect its because there are so many OLD websites, books, and projects that use them, and beginners dont know that there are newer, better, cheaper replacements.

The shower reference was a scary mental image!
 
reyandy said:
where i can find the best tutorials for pic16f628?

On my website :lol:

But all the 84 code out there is still relevent to the 628 (and all the other 14 bit PIC's), it only requires extremely small changes - mainly disabling the 628's comparators.

Originally almost all experimentors used the 16C84, this was the ONLY EEPROM PIC there was, this was later replaced by the 16F84 (a later silicon revision, with better security), then later still (but still last century) the 84 was replaced entirely by the 16F628.
 
I know I was jumped on when I mentioned the 16F84 awhile back.

But I bought tubes of them years ago for projects, then found the ATMEL AVR line and dropped the PIC (at that time, PICs had no internal OSC, then were cheaper, and there was a free rvkbasic compiler for them). But sometimes I see something already written for the 16f84, and I pull out a tube and burn one.

So that is why I did not know about the newer 628. And why I still have them.
 
Re: Why NOT the 16F84?


this does a good job of summing the various responses. However, as has been noted, the 628 (which has been obsoleted by the 628A!) is a mind numbingly easy drop in replacement. Literally, the 628A is 1/2 the cost of the 84.

as a teaching aid, why use a two generations old micro when with trivial changes, the 628A is usable. Frankly, I think the 16F88 is an even better chip to teach on since it also has ADCs and is boot loadable.

The other arguments seem to center on comfort. Frankly, I'm well older than you and love to learn new things. Getting my hands on a new chip to play with is just plain fun. Guess its a mind-set thing.
 
Same here, actually...

but never the less, people do stick with what they know. There's a story of the little old lady who, upon hearing that Ford was going to stop producing model Ts, went straight to her local dealer and bought five. The delighted salesman eventually asked her why she didn't buy a newer car, which came with the new easier shifting transmission. She replied,"because it took my husband three years to teach me how to shift that monster, and now that he's dead, there's no one left to teach me something better!"

I originally cottoned to the PIC several years ago because it only needed four clocks per instruction, unlike the 12 clocks per instruction used by the 'antiquated' 80C51s at work. However, we are now upgrading to processors from either Dallas or Philips. They use half or less the clocks, with a few enhancements that make life easier, while running the tens of thousands of lines of code we wrote, with a few quick mods.

Hey, don't look at me! I recently read a thread where the author quit after his department told him to continue teaching assembler for the IBM 360, a model he hadn't seen anyone write code for for many years!

And Parallax still thrives selling Stamps to the educational world at large. Every other supplier that has a processor with a bootloader claims to be the next logical step in the evolution to a processor better than the Stamp, but yuh gotta start somewhere.

I am now interested in the Cypress CY8... series because of the graphic programming environment they claim to offer. You drag and drop input, output and logic manipulation symbols into the window and it generates the code for you! We'll see how true that is when the kit gets here...

And progress marches (and shuffles, hobbles and staggers) on.
kenjj
 
well its funny the 16F88 being such a great susbstitute and good candidate as the new "16F84" as I find so little info and having got 6 of them am starting to wounder who will teach me to use em because the is nothing around about them.
 
Thunderchild said:
well its funny the 16F88 being such a great susbstitute and good candidate as the new "16F84" as I find so little info and having got 6 of them am starting to wounder who will teach me to use em because the is nothing around about them.

Try reading the datasheet, the 16F88 uses the same 14 bit core as the 16C84, 16F84, 16F628 etc.

You need VERY little changing from any other 14 bit PIC for the code to run on a 16F88 - obviously this is only downwards compatible - you can't expect code for a 40 pin PIC to run on an 18 pin one (unless it doesn't use anything that isn't available on the 16F88).

So check my tutorials, but you WILL have to change the config fuse values, but this is also dependent on your hardware configuration as well.
 
Thunderchild said:
well its funny the 16F88 being such a great susbstitute and good candidate as the new "16F84" as I find so little info and having got 6 of them am starting to wounder who will teach me to use em because the is nothing around about them.
Many of us learn by reading the Data Sheet, working through tutorials, experimenting, and studying examples.

Good luck. Regards, Mike
 

Attachments

  • 16F88 Boot Loader.txt
    13.9 KB · Views: 235
  • 16F88 PWM.txt
    2.3 KB · Views: 140
I am interested in the pwm program thanks but that is not taking an input is it? just making a fixed 10 % output. Am I correct ?
 
Thunderchild said:
I am interested in the pwm program thanks but that is not taking an input is it? just making a fixed 10 % output. Am I correct ?

The PWM output can be set between 0% and 100%, there's a tutorial on my site that shows how to use it - actually the two PWM channels on the 16F876/7, but there's very little difference.

If you wanted to control the PWM from an input you need to write the code to do so, the 16F88 has analogue inputs which you could use for feedback.

You might try examining the PICKIT1 source code, available on the MicroChip site, which uses this technique to generate and regulate the programming voltage.
 
I will go check all that out. I am trying to get started on mikroelektroniika's picbasic.

Nigel I don't think your program will do the 16F88 will it ? I couldn't find it on the list of pics or is it perhaps the same as another
 
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Thunderchild said:
I will go check all that out. I am trying to get started on mikroelektroniika's picbasic.

Nigel I don't think your program will do the 16F88 will it ? I couldn't find it on the list of pics or is it perhaps the same as another

It's in the latest beta version, you can download it from a link in the Announcements forum.
 
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