Week 6 - Electronics Design

group page // repo source files // objectives


objectives >

hero shots >


Altium >

I use Altium at work, but I am also familiar with KiCad. I started out on Eagle when I began using ECAD tools, back in the day when they were still independently owned by CadSoft (honestly not that long ago).

design rules >

For designing PCBs to be machined on the MDX-20, the only really important rule is clearance. All other rules can be somewhat derived from that one rule. Trace width depends on benchmark results.

Clearance for the 1-64 endmill. (mm)


Clearance for the 10mil endmill. (mm)


Trace width (copied from below for ease of reference):


attempt 1 - attiny44a >

oshpark >

I know others have done this, but I originally intended to benchmark oshpark turnaround vs cnc fabbing circuits.


I’ll fill in more details here later, but the short version is:

mods/fab - fabtinyisp >

I was on vacation for ~a week, and given how many bits I broke for the efab unit, I focused on making sure I could fab another fabtinyisp successfully.

mods montage


I succeeded, so I proceeded onto the actual board for this assignment.

efab - attiny >

efab efab

learned that I sent negative through mods, need to invert for mods to work properly. However, didn’t understand that at first. Assumed I had ignored design rules and made features too small. efab


should have done this during the efab week, but better late than never! feature benchmark to see if that was the cause of my bug. efab results are really good, so ruled that out. efab

fixed (inverted) artwork results. efab

the issue >

I thought I got components from Dan for the attiny44a, but we may have had a mixup… turns out I had all the parts for the samd11c. It took me a bit, but I implemented a new board using the libraries I built for the attiny for the samd11c.

attempt 2 - samd11c >

ecad >

another design montage! (I swear I’ll document this better later, it’s late and I need to function tomorrow).


some notes:

exporting gerbers. learned quite a few lessons during this process (described along with cam stuff below).


cam >

unfortunately didn’t capture the appropriate media here. a few lessons that I learned:

efab >


learned about another wonderful bug… seems like I should run at least one aircut before running any actual jobs with the mdx-20 (could just be a mods problem). some of the settings don’t “set” properly until after at least one run.

in this case, the origin is 10,10 by default, while I’ve been running jobs at 3,2. This explains the misalignment shown. efab

efab efab

unfortunately, I was doing this prior to work in the morning. Ran out of time, and learned that you should never rush when working with CNC… broke 2x 1/32” bits.

after I came back from work, did things properly and got a great result. efab efab

should’ve done some more homework before designing my usb footprint. pads line up fine, but definitely lacks the material required to align the usb in receptacle. efab

solder >

soldering mOnTaGe efab

snags I had to resolve:

ran out of 1uF caps and went searching for a switch part way through my solderwork, ended up reorganizing some of my inventory. efab

egads. turning a through hole switch into an SMT switch.

before: efab after: efab

hero shots >


breakout samd11c board >


after multiple spirals iterating on urumbu boards, I made a further spiral of the samd11c as a breakout board since I found myself exposing different pins quite a bit after successive iterations.

to easily program the samd11c later without a programmer, a bootloader must be flashed. I document this further in week 8.

programming >

with the bootloader flashed, I upload blinky to demonstrate programming. I follow Quentin’s directions as specified here.


samd11c board w/ blinky flashing.

© 2023 Alan Han   •  Powered by Soopr   •  Theme  Moonwalk