7. Electronics design¶
INTRODUCTION¶
This week I had to take some hello world board, redraw it, add an LED and a button to it, then mill and solder the components. After that I had to program it. My instructors advised me to choose AtTiny45 board.
Modeling¶
At first I had to choose with which software I am going to model the board. I decided to go with KiCad, because it’s an open source software and there are lots of good tutorials online. This one is a very short and informative
So I installed, opened a project, and started adding components. For the board I needed AtTiny45 2x 1K Ohm resistors 1x 10K Ohm resistor 1x button 1x LED 1x 1uF capacitor 1x 2x3 pin header 1x 1x6 pin header
Adding component is an easy task in KiCad
I added all the components in the schematics and connected with each other as needed, as shown below.
After that I generated a net from the scheme and opened it in PCBnew workbench. In this workbench I had to draw the traces in such a way, that they don’t cross. After playing with traces, using original design, I finally made it. I set the thickness of the traces 4mm. A very helpful thing is that you can change the grid size and be more precise with traces ()from the top bar). The clearance between traces would be at least equal to the diameter of mill bit (which is 1/64” = 0.4 mm)
At this point I had to export traces as an svg file. To do that, you just click File >> Export >> SVG
You need to export with these settings. If you check these boxes, you will have the outline in you svg as well.
I had some problems with sizes while exporting outline from KiCad, so instead of doing that, I opened traces with inkscape
I drew a outline using pen tool
Then filled the outline with black color and exported it as an svg file.
MILLING AND CUTTING¶
To mill and cut the board, we need to generate G code from .svg files. For that I used fabmodules.
Choose corresponding settings for each of them, and click calculate.
And then save, and send to the machine to do its job.
SOLDERING¶
I collected the components and headed home to solder them on the board. Instead of 10K Ohm resistor I took 5K Ohm resistor. I found a 10K Ohm resistor in a local store and used it instead. After soldering it looks like this
Conclusion¶
This week I used KiCad for the first time, learned how to design a board. I wasn’t very comfortable with designing and it was quite a torture for me, but totally worth it. I didn’t have time to do the programming, but I continued, programmed and finished this board in embadded programming week.
