DIY Arduino technical difficulties I followed this ArduinoToBreadboard and I just added a 5V regulator just to be on the safe side. 

So my questions are:


When I connect a Nokia LCD 5110 to the DIY arduino, nothing really happens but when I take out the AtMega328P-PU chip and place it to the official arduino board the screen works normally, why does this happen? (The pins are connected on the same way, it is not this kind of problem)
How can I make this DIY arduino to work with a 3.7V Li-op battery? Because the DIY board works only when I power it up with 5 or more Voltage it works perfect, so any ideas?
So. You say you have build an Arduino on a breadboard, is that right?


Have you checked all the pins, so they are all connected up properly? Can you post some pictures of the protoboard? Maybe you missed something, didn't connect all GND pins to each other if there are more on the arduino or something.
You can power the Arduino using a 3.7 Lion or Lipol battery using a boost-converter, here is a great video explaining how you can build your own (https://www.youtube.com/watch?v=QnUhjnbZ0T8), or you can just order one from Ebay.


Great Scott (the author of the video) also made a video on how to create a standalone Arduino: https://www.youtube.com/watch?v=J3DYgzRvLT8 . Check the videos out! Hope I helped you.