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18f2620

2020-10-02
2020-10-05
  • stan cartwright

    stan cartwright - 2020-10-02

    I wanted to try using pics again and the best I got is 18f25k22 from picaxe days.
    a comparison with a 328p ?
    anyway found a 18f2620 which looks pin compatable but more ram.
    it looks pin compatable.
    I see many problems using this chip on the forum.
    should I use it? does it need pps to set pins? that will be technical.
    or should I stick with 18f25k22 with only 1.5 kram.

    what's the bonus of using a 18f2620.
    what's needed pk2 or 3?

    where did the sticky connect pickit 2 to pic pins go?

     
  • stan cartwright

    stan cartwright - 2020-10-02

    ps...if using pps chips then they must have a default setup ?? like in the diagram,
    so why is a default definition not in pps tool for the device...
    so I don't need to use it.

    as I said I want to start using pics again but after avr they look complicated.
    one thing is they stay within spec at 3,3V supply and so 3.3V logic...or maybe don't.

     
  • Christos

    Christos - 2020-10-03

    pic's are good too ;-)

    programmings in pics goes to PGC/PGD pin (along with reset and gnd offcourse)
    both pk2 nad 3 supports

    the main diffirence most people have who used to useAVR and try pic's its the extended use of configuration fuses/ for almost anythink
    for example in most chips you have to select pins to be digital and yes this is not a universal selected constant.. its diffirent and diffirent behaviur in each chip

     
  • David Stephenson

    Stan the 2620 is a very old device . The voltage range is extremely limited. I would go with the 25k22 (or preferably a 16F equivalent).
    It is an interesting thought that maybe GCB should set PPS to default if the PPS has not been set in the program.

     
    • Anobium

      Anobium - 2020-10-03

      The PPS for RX is set be default per the datasheet for all PPS chips. The TX needs to have the PPS set and at the lowest level (assumming you had no Great Cow BASIC libraries) the ANSEL set.

      I think that setting a default for any PPS setting would be a bad a idea.

       

      Last edit: Anobium 2020-10-03
      • stan cartwright

        stan cartwright - 2020-10-03

        Anobium- pps is excellent gcb addition but using it needs data sheet know how which makes gcb seem complicated...and we don't want to make gcb seem complicated..I hope.
        My point is that pics have diagrams showing their pin functions...not fun.
        If a pic has configurable pins then it's data would show default values not can be anything..
        or maybe not and have to be set up.
        I only got a dev board that uses configurable pins and it had 500k ram and was a pain so didn't use it but it was usb programmable and you could use the terminal without rs232 to ttl converter.

        So what pic to use with gcb? talking about dil 28 or maybe 40 pin.?
        the 2560 I found is looking interesting with loads of ram and io pins.

        most gcb effort seems to be pics so go for pics or stay with avr which until I posted
        328p code seems to have been thought of not important but know evan Evan posts 328p code as quick answers.

        I've looking for/at your videos. I wish I had the gear to do a gcb pic avr comparison video.

         
    • stan cartwright

      stan cartwright - 2020-10-03

      Stan the 2620 is a very old device . The voltage range is extremely limited. I would go with the 25k22 (or preferably a 16F equivalent).
      I thought the point was 18f more better than 16f...but I'm thick

       
  • stan cartwright

    stan cartwright - 2020-10-03

    David "Stan the 2620 is a very old device". ta.
    18f25k22 was a picaxe chip before.
    I find pics messy compared to neat tidy 328p on an arduino board.
    I had this working at 3V but now rebuilding for 5v logic and still not working.
    a birds nest. and this pics pins are set as data so not even messed with pin setting tool...
    which looks very technical...very technical.
    pics...?? gcb avr for hobbyists..it seems easier as only a 328p...not the new atiny stuff.
    pics,so many,which one better than a 328p..which could be a 2560 board

     
  • stan cartwright

    stan cartwright - 2020-10-03

    I hope gcb a future, What users will it attract,
    pic users or avr users
    what would pic and avr users been using before...unless a complete beginner?

     
  • stan cartwright

    stan cartwright - 2020-10-03

    Why can't there be anothr gcb new users in stickys with lots of youtube links and maybe code?
    a thought. I would think that gcb developers to have as wide a subject subdirectory as possible.
    My only moan is looking for arduino solutions to hardware that is so popular
    it's in modules fron china for a few £ and there's years old support on arduino
    but gcb have to start from data sheets or seach for alternatives.
    the spi help is comprehensive but sill complicated or I'd right my own drivers.
    more gcb users needed more pr.
    more feedback about possible errors and sycophantic compliments :)

     
  • Christos

    Christos - 2020-10-03

    dont see why it should fail at 3volt both devices you mention are safe working at 3v

    btw i also think 18f are a bit more "structrucal" inside than 16f devices

     
  • stan cartwright

    stan cartwright - 2020-10-04

    I used 18f25k22 at 3.3V to get device logic to work at 3.3vn with displays.
    328p drops clock at 3.3v. don't know if 18f25k22 drops from 64mhz at 3.3v.
    I'm just a hobbyist.
    in picaxe days the 18f was "enhanced" and called X2.
    seems less spec than 328p but used it before. wiring is prone to errors

     
  • Christos

    Christos - 2020-10-04

    328 dont drop at 3.3 3.3 is stable
    you can use external oscillator to be sure of frequency, but better create an output that flash per second
    you will understand if you wrong frequency at significant values
    i.e. accidedantly selct 1mhz instead of 8,, oscilloscope is even beter offcourse

     
    • stan cartwright

      stan cartwright - 2020-10-05

      thanks Christos. I read it dropped frequency and went out of spec
      photo of nano at vin 3.3V driving 3.3v logic glcd

       

      Last edit: stan cartwright 2020-10-05

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