Let's say you just finished building a really 
neat circuit like this LED color organ I showed you in my very first video
It works well
But the construction on a breadboard like this is more or less a temporary solution
if you want to let the Arduino Uno stay intact
you can always build a shield like I did right here
and it also works without problems,
but this time I want to build inside this gadget box.
Soldering those components to a PCB is an easy task
But there's one component which doesn't really fit inside my gadget box: the Arduino Uno.
So today, I will show you how to break your
ATmega328p Microcontroller
free from its Arduino prison
and embed it into a circuit.
My first advice is to always test your circuit on a breadboard and as you can see it works for me
So we can move on.
We only need four external components:
one 16 Megahertz clock crystal and
two 22 Picofarad capacitors to generate the external clock signal and
one 10 Kiloohm resistor which connects between the reset pin of the ATmega and 5 Volts.
This way on my controller does not reset itself.
The crystal connects to pin 9 and 10 and one capacitor between each pin and ground
If you only need a clock of 8 Megahertz you could also scrape those parts and use the internal oscillator
But you would need to upload another bootloader
Check out the Arduino site for more information about that.
Pin 7, 20 and 21 connects to 5 volts and
pin 8 and 22 connects to ground
That is basically an Arduino on a breadboard
But there are some downsides in comparison to an Arduino board like:
No reset Switch
Only 5 volt input
No built-in usb to serial conversion
No short-circuit protection
and no overvoltage protection
But if you know what you are doing you don't really need those features
This is the pinout for the microcontroller.
If you used for example the digital pin 9 in your Arduino sketch
you have to hook it up to pin 15, and so on.
After I rewired the circuit on the breadboard
everything still work fine,
but now I want to change the code.
Here are three ways to do this
First way:
you just get your ATmega out of there and plug it in your Arduino and reprogram it.
This is the laziest and most annoying way
Second way:
you connect Tx of your Arduino board to Pin 3
Rx to pin 2 and reset to pin 1
and now you upload like always
The wires are just a bit longer this time
But make sure that no microcontroller is plugged in the Arduino
Third way:
you throw away the Arduino board
and get yourself an FTDI chip
which does USB to serial conversion.
You power it up and connect RX to TX and TX to RX and
Reset to Reset and it is done.
Now you can also use the Arduino IDE to upload your sketch like usual.
There's also another way which involves in-circuit serial programming or
ICSP for short
But it is messy and requires a special programmer and another software
If you want to be really advanced, you can take a closer look at this principle... somewhere else.
That is basically all you need to know to make your own Arduino on a breadboard.
Of course I also finished the gadget once I was sure everything worked on the breadboard
I also added female headers on the Rx and Tx line in case I need to reprogram it
I hope you learned something today
Like always stay creative, and I will see you next time
