Running programs from external storage

Hello!
I am currently in the process of developing an Arduino-powered wristband. The device will be able to run different tools, or apps, that do different things. The issue is one of storage and convenience. I don’t think that I could fit all of the programs within the Arduino’s storage area, and would prefer the programs to be on something like an SD card that could be modified from my laptop. This would also mean that I wouldn’t have to re-flash(?) the Arduino every time I make a change to a program, and would just have to re-compile a separate sketch and replace it with the copy on the SD card.
Is there a way to do this?

Thanks in advance,
Mercury

No, not really. You could maybe write a custom boot loader to get code from the SD card.

Have you seen this? http://hackaday.com/2012/02/21/flash-an-arduino-from-an-sd-card/ Best regards Jantje

and there is a thread on this forum http://arduino.cc/forum/index.php/topic,16812.30.html

bitlash is a command interpreter that can be converted to something reading from disk...

Thanks, Rob. Here's a link to the "bitlashsd" example, which will run Bitlash script off the SD card:

https://github.com/billroy/bitlash/blob/master/examples/bitlashsd/bitlashsd.pde

It's in the File->Examples->bitlash menu once you've installed Bitlash. Do read the doc, there is a minor code change to the Bitlash core to enable file script support.

Good luck with your project,

-br

Thanks for the ideas, but I would prefer a way to use only one Arduino. I'm not quite sure that I'll be able to fit all the support electronics into the wristband as it is, but it I have to I'll give it a shot.

Mercury1964 If you have a size problem take a teensy2 (100% Arduino compatible) and your physical size drops. As far as I understand together with the Bitlash the solution should be physically smaller than an Arduino. Best regards Jantje

Note: The power consumption of the teensy2 is smaller than for a standard Arduino which I guess is important for your project as well