Assignment - Electronics design
- I -- group assignment:
- - use the test equipment in your lab to observe the operation of a microcontroller circuit board
- II -- individual 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 it extra credit: simulate its operation
To solve the task assignment I followed the instructions on the page: Kicad Electronics design
I installed the program from the site: Kicad
Then I made new project - Atiny45.pro
Next step was to create schematics with Eeschema
Then I had to import libreries - fab.lib - with FabLab electronic parts symbols
After that, I started drawing the scheme by placing and connecting - wiring the symbols
After I inserted the symbols it was necessary to connect them. I made the connection using the wire command.
After drawing the symbols and adjusting their settings I generate a netlist and after that I was ready to make PCB
After trying to place the symbols my PCB had the following look
It was time to make .png from .svg that I made in KiCad.
For making png I used Inkscape
Each layer of the scheme - traces, outline and background is placed on its own layer, so that new layers are made and transfer each part to the appropriate layer.
I made export of outline.png and traces.png adjusting properties
The end result is
I made import of outline.png and traces.png into fabmodules
and make calculate
However, while we were doing this task - since we are not in FabLab itself, but working remotely, I was not able to work on a CNC machine. For that reason, I made this tile in a slightly different way. I took a photo sensitive tile and cut a piece.
To make a PCB this time I used an etching method. After the PCB is exposed to the UV light it goes into the developer and then in a etching solution. Whole process can be seen in Electronic production week. The results can be seen in the following image.
For etching I used hydrochloric acid with hydrogen peroxide in a ratio of 2: 1. With gentle stirring after 3 minutes the pcb was removed from the acid and washed with water.
After washing and sanding it was time to solder.
And the result is ...
I followed the instructions on the page: Programming ATtiny85 with Arduino Uno I programmed a simple sketch. When the button is pressed, the LED lights up.
Sketch code in arduino
For the group assignment we had to use the test equipment in our lab to observe the operation of a microcontroller circuit board. I used digital multimeter to read voltages.
I measured the voltage when the led is on and off. You can see in a picture measured voltages.