Arduino Forum upgrade scheduled for Monday, October 20th, 11am-4pm (CEST). Sorry for the inconvenience!
Pages: [1]   Go Down
Author Topic: Is it possible to use a different pin for MISO?  (Read 786 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 2
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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
Logged

Left Coast, CA (USA)
Offline Offline
Brattain Member
*****
Karma: 362
Posts: 17320
Measurement changes behavior
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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
Logged

Southern California
Offline Offline
God Member
*****
Karma: 5
Posts: 539
I like blinky lights
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

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
Logged

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

Offline Offline
Newbie
*
Karma: 0
Posts: 2
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Thanks, both - really helpful info.

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

Foeh
Logged

Left Coast, CA (USA)
Offline Offline
Brattain Member
*****
Karma: 362
Posts: 17320
Measurement changes behavior
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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. smiley-wink

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

 
Logged

Peoples Republic of Cantabrigia
Offline Offline
God Member
*****
Karma: 6
Posts: 722
Arduino happiness
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

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...
Logged

Offline Offline
God Member
*****
Karma: 4
Posts: 813
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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

Peoples Republic of Cantabrigia
Offline Offline
God Member
*****
Karma: 6
Posts: 722
Arduino happiness
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

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.
Logged

Global Moderator
Netherlands
Offline Offline
Shannon Member
*****
Karma: 234
Posts: 14296
In theory there is no difference between theory and practice, however in practice there are many...
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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

Rob Tillaart

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

Pages: [1]   Go Up
Arduino Forum upgrade scheduled for Monday, October 20th, 11am-4pm (CEST). Sorry for the inconvenience!
Jump to: