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Topic: Is it possible to use a different pin for MISO? (Read 798 times) previous topic - next topic

TheClam

Hi, all.

I'm trying to use an Arduino Nano as an ArduinoISP so that I can burn a plain ATmega168 chip. The only hitch is that pin 12 is fried on my nano...

It seems unlikely but is it possible to use a different pin for MISO? I can't find any reference to relocating any SPI pins other than SS.

Thanks,

Foeh

retrolefty

No, the SPI signals are "hardwired" to internal hardware that performs the SPI functions. However I guess someone proficient enough could write a software SPI functions using different pins and then rewrite the ArduinoISP sketch to utilize that software SPI function. Sounds like a lot of work, better to find a way to buy a new Arduino board. A 'clone' arduino board can often be found on E-bay for around $20 if money is tight.

Lefty

magagna

I agree with retrolefty on replacing your board, but if you want to try it in software here's some code from someone who's done it:

http://little-scale.blogspot.com/2007/07/spi-by-hand.html

Good luck,

Chris
http://en.wiktionary.org/wiki/magagna <-- My last name.  Pretty apt.

TheClam

Thanks, both - really helpful info.

It's just typical that the one pin I blew happens to have a key purpose!

Foeh

retrolefty

Quote
It's just typical that the one pin I blew happens to have a key purpose!


It comes under the same law of physics that states a dropped peice of toast will always fall buttered side down. ;)

Most the I/O pins on a Arduino have secondary functions, so it's never nice to have a non-functional I/O pin.

Lefty



Constantin

Another option is to unsolder the fried CPU and solder on a new one. Not too expensive when ordered from Digikey, et al and it'll teach you drag soldering in the process! It's something I'll be doing with my mini-pro after applying a bit of too much voltage to one of the analog pins...

jwatte

I think the Ruggeduino sounds like a good idea, given the experiences you describe.
http://ruggedcircuits.com/html/ruggeduino.html

Constantin

Yeah, the Ruggeduino is one fantastic little unit that is a terrific value. All the benefits of a Uno plus voltage protection with minimal additional cost.

robtillaart

FWIW For "moving" pins this shield is sometimes an option - http://mayhewlabs.com/products/go-between-shield -
Rob Tillaart

Nederlandse sectie - http://arduino.cc/forum/index.php/board,77.0.html -
(Please do not PM for private consultancy)

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