- Be sure to erase the device before you load a different program into the micro-controller
- Make sure your 9v battery is full and properly soldered
I used to have this exact same problem and it took me 2 days to figure it out. I just got myself a new 9v alkaline battery as the rechargeable battery I was using was empty upon delivery and I didn't have a charger at the time. Boom - everything worked.
However, I understand there could be multiple factors involved. Prior to the battery problem, I had multiple short circuits at the programmer header due to my messy soldering. Post a picture of your circuit from underneath where the soldering was done. Try to use Macro settings on your digital camera . . if you own one . . and take pictures from different angles.
Debugging can be very frustrating but in my experience it helps to use the 'elimination method' which goes something like this:
- Is the Battery out? Let's unplug the battery and try that again. See what changes and what doesn't.
- Is this ground cable broken? Let's unsolder it. See what changes and what doesn't.
I managed to build the robot alright. I just screwed up the LED - and one of the servos is wearing out, often running slower than the other one, then all of the sudden speeding up. Really frustrating, but it's a great learning experience. That's the whole point of the journey - Not just so you can follow the instructions and be Done with it.