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Topic: atmega 1284 help with pinnout (Read 12344 times) previous topic - next topic


i cant imagine massimos group can ignore this chip any longer. huge loss in profit once people wake up to the cost benefit of the m1284. i suspect before the end of the year this core will be part of the standard distribution. thanks again.

I doubt it. Have you seen support for *any* other board not made by "Arduino Inc" in a Arduino s/w release?

That is why you are already seeing forks.
the guy that forked the ide to get lots of fixes and really nice feature updates into the windows IDE.
Paul with his teensy3.
(I have several personal updates I do to the "standard" core code to make the code smaller and faster for my builds)

While the source may be open, and it is possible to extend an Arduino s/w release with new core support,
the process of getting things into the official release is still very closed.

--- bill


While the source may be open, and it is possible to extend an Arduino s/w release with new core support,
the process of getting things into the official release is still very closed.

Yes it is frustrating at times. Several years back I got a 644p based board and installed the files needed to make the IDE work with it (around version 11 or 12 I think), but every time there was a new IDE release I would have to redo the mods and after a while I just stopped bothering. I understand the newer versions of the IDE make that effort easier but I keep misplacing the links for the detailed information steps required for actually adding a new board to the IDE.

But I can also kind of see their position too. If they indeed provided direct support to any and all 3rd party 'arduino' boards using different processors or clock speeds with their 'official' offerings, would they then not end up 'owning' all the support issues, bug reports, request for minor changes, etc, they included with the official release including the bootloaders? Sounds like a support headache they would probably like to avoid.



what i meant was massimo should come out with an m1284 board himself. this would establish a standard pinout which, from browsing the "end to end" thread, seems to account for 2/3rd of the difficulties with this chip. the current thread being another example. the remaining 3rd may be a result of arduino deciding to abandon atmel pin designations in favor of arbitirary numbers but not much to be done about that at this point. however producing a new "official" 1284duino might force some of these wild and crazy innovators (present company excepted of course lol! ) to use more reasonable pinouts.


Nov 24, 2012, 06:03 am Last Edit: Nov 24, 2012, 06:09 am by CrossRoads Reason: 1
What  would you consider a reasonable pinout?
For my '1284P designs, I tried to select the pins for  shield compatability:
D0, D1 for serail(0),
D13-12-11-10 for SPI,
A4/A5-D18/D19 for I2C
The rest just followed from what was open.
That seemed reasonable to me, vs having to hunt around for Serial tie-ing up these pins, SPI tie-ing up those, and I2C yet somewhere else.
So more Uno like than Mega like.

Everything is a tradeoff.
The "standard pinouts" do not take full advantage of available pins. The Leonardo for instance, a few more IO pins could hve been made availabe in my opinion.
Fortunately the open source nature allows one to come up with a form factor & pinout, and if catches on, great, and if not, other things are always possible.

Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.


with only a few hours experience imo the bobuino has reasonable pinout and if adruino company does produce a board hopefully they will adopt it. ive read the whole "end-to-end" thread now and the process for choosing pins made a lot of sense but it wasnt always like that. for example some designs had the led on pd7 instead of pd5 which caused me some confusion ruunning the official blink demo. and as mentioned using uart1 instead of uart0 prevents use of 2 very useful direct ints on those pins. the uart0 pins do not have any more useful function and make a better boot interface. i realize there were rare and early problems with uart0 but this is now. and the story behind the extra adc pin selection was interesting too. as a hardware engineer i understand picking and choosing pinouts can be the secret to success and glad your board turned out so well. anyway thanks again to you guys and maniac bugs effort for helping me get this running.


Nov 24, 2012, 01:14 pm Last Edit: Nov 24, 2012, 01:51 pm by LittleJ Reason: 1
hey john no problem for the hijack ;) i solved my problem burning the original-mighty 1284p 16mhz bootloader and got the jtag fuses disabled the pinnout changed a bit but not much. im down to etching some pcb today ;) hope all goes ok ;)


glad to hear your problem was solved as easy as mine. these guys are great.  i also ran into the same jtag lockout a while back but on a different chip. im curious, did you fix the jtag issue by changing fuses or from within the program like in florincs post?

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