I never used it with external power until one day I wanted to do an autonomous robot. I programmed some test code, removed it from the USB port, powered the auxiliary power supply (a.k.a 9v battery) and nothing...
The usual debugging technique followed:
- test program with USB, it worked.
- remove from USB, change switch to external, power external and wait...wait..nothing.
- check the web... I found here that the problem existed and already had a solution.
- while browsing "problem Arduino NG" I also found here that the "autoreset" feature of the diecimila had been implemented.
So I picked up the soldering iron, my pack of SMD components and went on to hack the board. So I changed the 3rd resistor from the top and I placed the capacitor just below the RX Led (a reader told me it was very clear what I had really done to the board...)
Here is the final result:
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