No-USB Small-Cheap-n-Excellent Arduino
Several times we set-up our standalone atmega on a bread boad, but this takes a lot of space on our bread board leaving almost no room for other components. So I decided to create the same on a stripboard/veroboard to save some space on the bread board. Plus this is sturdy and has a small footprint. Parts will not be loose on vibration as they are soldered. Cheap. Parts are common and easily available at local market.
This type of projects are available on the internet, but none of them were suitable for my requirement, so decided my own and easy to build version. It works perfectly and it can be used with a USB-TTL board also.
Modification: I used a 100nF Ceramic Capacitor between AREF and GND, and left two headers (single line IC Base/Bus Strip/Machine PIN Female Break Away Header) between AREF and Vcc (+5V). If you are using board's own voltage as analog voltage reference then use a RED jumper wire between them. If you are using a sensor which operates at 3.3V and you need its voltage as Analog Reference then pull out the jumper and use the sensors voltage (Vcc).
Here are some good descriptions about Arduino/ATMEGA piout and AREF pin function.
I use my UNO R3 as ISP to upload sketches.
Using a regular ATMEGA328P-PU (pico power) is quite straightforward, you can follow the steps shown here. Just see the last picture.
I powered this little board with an old computer SMPS. I bought this junk PSU from a repairer who repairs all kind of SMPS. I paid him just Rs. 200/- (Indian Rupees) (nearly
NOTE: Do not connect the Voltage line of one device to another, this can fry your circuits. But you must connect the all the Grounds from all the devices together.
Rather than using a Regular pico pwer chip I used An ATMEGA328-PU (non-pico power) instead which has a different fuse bit. Otherwise its same as the regular one.
If you want to use the same controller as mine, here is the way:
Assuming you are using Arduino IDE 1.6.4, put the following lines into boards.txt and restart Arduino IDE. Then use my codes (BAT files) to set a proper fuse-bit. Select the right board from the Tools menu then burn the boot-loader. Now you can directly upload via IDE or if you want, you can compile the code with a batch file and then upload via command-line avrdude (just skip the boot-loader burning step if you planned to use command-line avrdude only).
PS: Cutting the tracks on a Veroboard is described here. A good isntructable.