I was restructuring a quite large app with soft-reset/watchdog (avr/wdg.h) methods and accidently called these inside the setup() routine. Now my Arduino is coniously resetting and doesn't seem to accept attempts to upload new code.
Does anybody know how to get new code up to the Arduino or did I broke it?
The watchdog doesn't get stopped by a system reset, but it will by a power cycle.
You can try uploaded a fixed sketch using power-on instead of reset button to get into the bootloader, which MIGHT work depending on exactly which bootloader you have.
It describes how to use the arduino diecimila-board itself as a simple programmer (with only a four-pin socked soldered to it and a few wires added)! If you have a windows-pc at hand, this is the easiest and cheapest way to burn a new boodloader!