Perfboard Hackduino (Arduino-compatible circuit)

Step 4 Finishing the Power

I would never do this when actually building this circuit, but for tutorial purposes I felt it to be the clearest way to show you how I am taking power from the 7805 and sharing it with the board.  In fact i recommend that you do not put any wires on top of the 7805 as it can heat up quite a bit, particularly if you are inputting more than 9v. Go around the 7805 on either side. Down the center of the perfboard you can see two rails that go down the center of board, which I am using as power rails (similar to the outer rails of a breadboard). I have chosen one to be ground, the other to be power  (+5v).

From behind the 'chair' (7805) you can see I have taken the input voltage pin and ground to two terminals which is where our battery will plug in.

Lastly, install the 22uF capacitor across your power lines somewhere after the ATMega chip.  In this case I am putting it at the end of my power rails. Be aware of polarity when using electrolytic capacitors - match the ground of the cap to the ground rail.  This is important!

**if you haven't noticed by now, I ran out of red wire and am using blue for positive and the standard black for ground.

Comments

[eboily]

If I properly read your pictures, both capacitors are between GND and OUTPUT. I thought that 7805 also needed a capacitor between INPUT and GND...

Am I reading correctly?

Thanks