Uuh, swell! With all the software challenges I did not care for hardware restrictions. Now I got about 21kB to squeeze into the Mini's memory... even without the sensor comunication.
Did anybody ever change the 168 for a 328 on an Arduino Mini board and it worked? I do have a USBtinyISP and spare chips, so the bootloader might not be the problem. I only find that it is "irreplaceable", well, how irreplaceable exactly?
Thanks
Sebastian
_ _ _ UPDATE _ _ _
Irreplaceable my ...! HA! It IS possible to change the chip! OK, it is not a walk in the park, but it is definitely possible:
I cut of the chip, because I didn't want to temper with the other components by heating the entire circuit board up. I used my swiss army knife after rejecting the idea do dremel it of - there are lots of vias under the chip, so I think it is safer to cut the pins. Then I cleaned the pads from the pin rests and checked for connections between the pads and also if the pads still were connected to the outbreak pins. Soldering the new chip onto it was quite challenging. Started with a corner pin, then adjusted neatly and attached the opposite corner. Then one pin by one, using a desktop lamp and a magnifying lens to see when the tin got liquid and sucked under the pins. Next time I use one of our stereo microscopes for that. Anyway, afterwards I checked again for shortcuts and corrected. Then I burned the bootloader with my USBtinyISP. And then I used my Duemilanove to upload sketches; this worked with "Duemila or Nano w/ ATmega 328" selected as board, not with the "Mini with ATmega 328". Happy happy, joy joy!
Some additional remarks:
- I didn't use extra tin but only the rest on the pads. I do not have SMD soldering paste yet.
- I know there is a Mini with a 328 available, but I have no possibility to get one here (within a week or two. Besides: everybody could buy one
).
OK; the basic problem remains, though, but we will try something about it next week.