Class 2 Office Hours Q&A:

Here are the Questions (and answers) from the Class 2 Office Hours Q&A

• What exactly is this project that we’re designing? What might it be able to do?
  • Functionally, not very specific. I had to choose something where I could demonstrate as many features as possible. Having said that, this drives the RGB LED’s, so it can be used as a Badge, or a trinket. I’m not covering the programming, but loading the Arduino bootloader, and then running the NeoPixel demos should get it to light up
  • Doing some Googling, I found these couple of projects (there’s likely many more) that use the ATtiny85/WS2812B combo.
  • https://www.instructables.com/id/Use-a-1-ATTiny-to-drive-addressable-RGB-LEDs/
  • https://www.electromaker.io/blog/article/programming-ws2812b-leds-with-attiny85-23

• Was there a reason to place the Neopixels closer to the edge of the board instead of the mounting holes? I would think that placing the mounting holes closer to the corners would be preferable.
  • The plan is that when we make the enclosure in FreeCAD, the main circuit board (area within the mounting holes) can be enclosed, while the part with the RGB LED’s can stick out / be exposed.

• If in-case, my logo size or the layer is wrong, how do I change those parameters?
  • There’s no easy way, other than going back to Bitmap to Component converter, and regenerating the symbol / footprint all over again.

• I’m pretty bad with electronics. I notice that between the end of Class 1 and the start of Class 2, the schematic has changed, which is throwing me off, because I don’t know the missing steps that got from version 1 to version 2. Specifically, I now see a box around the connectors at the end of the LED chain. But, more importantly, when I was watching you assign footprints, you have a “5V” (J4) that I do not have…
• UPDATED: I’m guessing you customized the connectors to add boxes around them. And changed the power supply, changing the female connector to male, and adding a female connector between the end of the Class 1 and the beginning of Class 2.

• Yes, sorry about that confusion. Anyhow, I’m posting my project files on Github, so you can clone that repo, and compare.
• https://github.com/wyolum/HackadayU_KiCad_FreeCAD

• My default in Board setup is quite different from yours. (I’ve never used it before, so this is what it installed with):

UPDATED: I did not know mil as an imperial unit. I see now that the above values are the metric equivalents -- or close to -- the mils shown in your defaults.

• Try changing the project “Units” to INCH instead of MM. In Schematic/PCBnew, the second and third toolbar icons toggle between these two.
• Then, in PCBnew > BOARD SETUP > DESIGN RULES > NET CLASSES , you can set it up.  I’m posting my project files on Github, so you can clone that repo, and compare.
• https://github.com/wyolum/HackadayU_KiCad_FreeCAD

• In Board Setup, when you are changing the widths of the routing, I see you have /A1, /A2, /A3, /D1, and /D2. Mine does not have those labeled that way. When / how did that happen?
  • I wanted to show how the BUS function works, so I made some changes to make that clear and renamed the nets. Actually, I made some more changes, so best to clone my version from the repo (see link above) and let me know if you need help to replicate my version.

• My SPI PROG footprint is “backwards” with pins 1, 3, and 5 at the top. I hope the right thing to do was to mirror it in the Footprint Editor, save as tiny_blinky, update the Symbol Fields in Eeschema, and change the footprint in Pcbnew… It now looks like yours…
  • Ummm, Prolly. Did you try ROTATE / MIRROR / FLIP (X/Y) options within Schematic itself ? Maybe if you share a screenshot, we can sort it out.