Designing the Board
I designed my own version of the Echo Hello World board on Eagle. It took me a while to realize/remember that there was a specialty library with all the correct pieces for the board. I placed the existing pieces on the board and used the same connections to the attiny44 for easier programming. I also added a button as well as a led and resistor off the power line that could be used as a power indicator. Setting up the schematic wasn't difficult. Routing the board was extremely difficult. After many attempts and moving around the pieces I managed to create a board design. I exported the board at 500 dpi and went to mill it.
![](../images/schematic3-56.png)
![](../images/schematic3-53.png)
Milling the board
On my first attempt to mill the board, I set the resolution to 500 dpi which ended up huge. After a couple of Google searches, I realized there was a bug in Eagle on the Mac which doubled the size of the board.
On the secound attempt to mill the board I increased to 1000 dpi which fixed the sizing issue. While the traces were milling I noticed that there was shiny parts still on the board and that the bit wasn't zeroed properly. I also noticed that the traces were extremely thin. I stopped the job, rezeroed the bit, increased the width of the traces in Eagle and started again.
On the third attempt milling the board worked!
![](../images/schematic3-3.png)
Sautering and Programming
Sautering the board was very straight forward.
![](../images/schematic3-20.png)
Because I didn't changed the connections to the attiny44, I used the same code that was provided to code the board. My power light successfully lit up when connected to FTDI. While I had added a button to the design, I did not change the code to incorporate the button because input devices and programming were on a later week. The code ran and the hello world executed properly.