Breadboard Arduino: Fast, Cheap and Fun
If you’ve been enjoying making stuff with the Arduino, but don’t want to buy more Arduino boards just to make a new project, fear not—you don’t need them!
- ATmega328 (with Arduino bootloader)
- 5V regulator (i.e. L7805)
- .1µF capacitor (the little yellowish disc kind that says “104” on it)
- 16mhz resonator
- 10kΩ resistor
- >5V power supply (can be any power supply you have, such as wall-warts, since we’re using our own regulator)
- Optional: FTDI USB breakout board (for programming from a computer)
The bootloader is what makes the microprocessor easy to program with the Arduino environment. You can also buy ATmegas without the bootloader for about a dollar cheaper, but they must have the bootloader manually loaded on to use Arduino.
If you have an ATmega that’s already loaded with your program, you can just build this board as-is without the capacitor and leave pin 1 (RESET) connected to +5V via the 10k “pull-up” resistor. You can even program a chip on an Arduino, remove it and plug it into your breadboard setup.
The one part remaining that I haven’t mentioned is the programming header I made, on the top right of the top photo (fully visible in the second photo). This connects to the FTDI USB board I describe in my easy breadboard Arduino programming tutorial. The pins are, from top to bottom: Ground (Black), RX (White), TX (Green), DTR (Yellow).
Lastly, though not pictured here, it is good practice to use decoupling capacitors on your power supply to protect your microcontroller from any irregularities, as described in this tutorial (a few pages down).