Gabriella Perry


Assignment: Redraw an echo hello-world board, add (at least) a button and LED (with current-limiting resistor). Check the design rules, make it, and test that it can communicate—extra credit: simulate its operation.

For this week's assignment, I started by reviewing past year's board designs. I found Julia Ebert's page from 2017 super helpful, and it helped me get started. I selected the ATtiny 1614 to redraw. Rob Hart recommended this as the ATtiny microcontrollers did not require a bootloader. I decided to use KiCad since Zach demoed it in the recitation, and I have a personal vendetta against fusion.

Board Design + Fabrication:

The biggest struggle within KiCad was getting the footprint library to download. It would import as a project library but would not show up as a global library. Another issue I found with KiCad was that I could draw traces that were closer together than the machine could mill. This lead to my first board having unintentionally connected trace paths. I rerouted some of the trace paths to fix this issue and then re-milled the board. Soldering all of the components was reasonably straightforward, besides a small mistake because I did not realize LEDs have to be oriented in a specific way.

Testing the Board:

In the previous electronics week I did not make an ATtiny board so I did not know how to program the board using UPDI. Rob Hart walked me through the process which requires programs to be loaded using another board. For this we tested different methods of communication. First we used the CH340 board rigged with jumper wires and a diode on the UPDI wire to program the board LED to blink. We had to download the driver for the CH340 and the ATtiny library, but otherwise it was an easy process. We also programmed the board using the hello.D11C.serial.5V.1.1 board and the hello.serial-UPDI adapter board found in week 3's documentation. We used an FTDI 5 volt serial communication cord for the echo test to communicate with the board after it was programmed.

The testing verified that the board could successfully echo and blink!

Check out Board Testing Here!