Nuts and Volts

then pasting the blocks to the indicated files.

Open these files in a text editor such as Programmer's Notepad. You will copy a block of code to each of these files and then save them back to their original location. Just to be safe, make a copy of the originals of both files before changing them in case you mess something up.

You can get the two blocks of text from a zip file that you can find at the article link. The file name is 'ArduinoISP Atmega328 files.zip' and it has two text files in it: 'Add to Arduino Conf File.txt' and 'Add to boards dot text.txt.' Open these in your text editor and do like the name says — add them to the indicated files arduino.conf and boards.txt.

One final caveat: This design works for the Atemga328. It may work for other 28-pin ATmegas, but you are going to have to figure that out yourself. There is a bit of Internet chatter on how to modify the original ArduinoISP design and associated files to do this, but since I'm only interested in rolling my own Arduino with the Fritzingduino concept, I'm not interested in pursuing other ATmegas at the moment.

ARDUINO + SHIELD = SINGLE PCB

We've discussed the economies of rolling our own Arduino with the Fritzingduino, and we can extend those economies by adding our shield designs to our Fritzingduino so that we have a single PCB and don't need those male/female shield connectors. For example, we've learned to design an alarm clock for an Arduino shield. We could add that shield design to our Fritzingduino and have the whole thing on a single PCB, thus saving us the cost of the Arduino, the shield, and all those headers.

Since we want to get this all on a single PCB, we don't need standard Arduino headers to accommodate a shield — there is no shield. First, we want to create a Fritzingduino base design that has no headers. Figure 10 shows a schematic view for such a design; Figure 11 shows the PCB view.

We call this the Fritzingduino_No_Shield and as you can see, it isn't much use as-is. However, it provides the minimal Arduino clone circuit for our 'Arduino + Shield = Single PCB' equation, so let's save it as Fritzingduino_ No_Shield.fzz so that we can reuse it in the '+ Shield' designs. You’ll find this project at the article link.

FRITZINGDUINO + ALARM CLOCK SHIELD = FRAC

Battlestar Galactica fans will like our new acronym: FrAC. You'll want to open the Fritzingduino_No_Shield.fzz file and then save it as FrAC.fzz. Next, open the Alarm Clock.fzz file (at the article link) shown in Figure 12.