Hi: Me and 2 friends started building the 50$ robot separately, I got it to work and they could not. Now, when I was checking their board against mine I noticed that they had the AVcc pin connected to the VCC pin on the board which according to the pdf schematic is correct. I had not connected this pin and my board was working correctly(controlling servos, receiving input from sensors and led), my friend's boards were not being recognized by the programmer, so I told them to eliminate that connection and it worked for both of them.
Why is that? The schematic says that you are suppose to connect those pins and when I tried just to see what would happened to mine, the controller got really hot as well as the regulator.
Is the schematic wrong? I have the atmega168. Like I said everything works fine without that connection.