Perfboard Hackduino (Arduino-compatible circuit)

Step 10 Power Terminal : Battery/supply connection

We are very close to finishing the circuit!

I have chosen to install female header pins to the input power supply terminals.  This so that I can easily pop in and out any supply I want.  However, for a board that will be going in to a specific project, it is a good idea to just permanently solder in your power supply.  Perhaps it is a 9v battery clip. Or a DC wall adapter.

Now that we have finished soldering everything, use your multimeter to check continuity between the power rails.  There should be no connection between the two.  If the multimeter says there is go through and check for where there is a short.  This could be harmful to the chip if we power it up and there is a short.

This is also a great time to check that your voltage regulator circuit is functional. Plug in your power supply and turn it on without the chip inserted into the socket. Use your multimeter to check that exactly 5v are running between the power rails.  Because all of our power pins are connected to the rails, we know the chip will only receive 5v - just like we want.

Comments

[jderque]

 If you intend to keep those headers as power terminals, I strongly suggest to add a diode (such as 1N400X) to your circuit so that your chip won't be damaged if your battery is plugged in the wrong way. Those headers are error prone, and diodes are cheap as hell...

Otherwise, that's a nice little board :-)