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Topic: Self-ISP on an Uno (Read 7 times) previous topic - next topic


Here's something fun: it's an Arduino Uno doing ISP on itself!

The 8U2 USB chip is running modified software - essentially the standard USBserial code, merged with a heavily modified version of the ArduinoISP sketch.  The nice thing is that it can switch between normal operation and ISP just by adding or removing a jumper.

If anybody is interested in trying out this code, let me know and I'll tidy it up and write some instructions.  You'll need an Uno R2 (R1 will not work; R3 is probably ok but I don't have one to test) and either an ISP programmer or another Arduino.  Some soldering is required (to add the extra header pins).  You'll also need to be fairly confident about reprogramming the 8U2 - as always with ISP, there's potential for bricking the device if anything goes wrong.


That's pretty glorious, I love it.


Looks like a slick mod to the Arduino - What ISP do you tell AVRDude you are using?

I could see making a cable that when plugged in puts the 8U2 in ISP mode and when removed it works in normal Arduino mode.A 10 pin connector on the one end witht he 2 pins shorted. A six pin connector on the other end.

This might be a good addition to the Arduino design. And it could be used without having to load a sketch in your Arduino chip.

Will you post your code and the procedure for loading it in the 8U2?


This is comparable to what you could do with a duemilanove.


Early rev Uno's did not support, it is nice that the later ones finally broke out the pins to support this.

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.


Kick ass!  Dunno if I'd use it, since I tend to use ICSP only for naked chips, but that gets +10 clever points for sure.

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