This time I went about building my own low cost Arduino clone. To make sure that my design was consistent with arduino boards, I used Sparkfuns RedBoard design as a reference.
At first I wanted to attempt a single layer layout. As you can see, I ended up using lots of jumpers 😦 Also, I customized the board to use SOT223 packages for the voltage regulators (bottom layer). I had to use male header pins for the IO’s as my component stash was void of female headers.
Downloads: Eagle Schematic and Layout
The board makes use of an atmega328 with an UNO bootloader. You can either purchase a bootloaded chip or load the bootloader using a programmer. Here’s a list of sites that sell a pre-bootloaded Atmega328:
You can also use an existing bootloaded chip to dump the bootloader on the chip you want to program.
The jumper near the LED can be used to choose whether the chip should operate at 3.3V or 5V.
Lastly, To connect the board to a computer you will require an external USB to TTL serial converter. I had a tough time trying to solder a CP2102 MLP-28 package and so decided to design my UNO board without direct USB support 😦 But this has led to some cost savings 😀 The overall expense came to about 300 – 350 INR.