Eagle SCH and BRD


^ (Project using Beetle board instead of custom PCB)

Custom PCM Eagle files and PDF: https://github.com/hellonun/homemade_hardware/tree/master/slide_pcb


  • Do we need to connect GND and VDD on each side of the chip together?
  • How much warning is allowed regarding the wire touching (the pins on the chip already has warning)
  • What are the 5×2 pads on the sides of the micro USB? Are they to lock the cable? Or should they be connected to something?

NOTE: the 3 headers are to connect to the slide // I tried to model the slide but doing it this way saves space because the USB connector is at the same spot as the pins on the slide

Screen Shot 2563-04-18 at 18.49.56.png

(Maybe I want to make cut-corner edges to make them fitted to the wood/acrylic underneath)

This is the sketch of each layer of the device. The PCB in this case will replace the Beetle board (at the bottom).


Once assembled, the device will look like this







Homemade Hardware Update

Prototyping board

Beetle - The Smallest Arduino Board with bluetooth 4.0


Chip ATMega32U4 (big pins)

ATMEGA32U4RC-AUR Microchip Technology | ATMEGA32U4RC-AURCT-ND DigiKey Electronics



WMYCONGCONG 10 PCS 10K Ohm Slide Potentiometer Single Linear 10K Electronic Potentiometer, 88mm


I had a problem with the slides because they turned out to be logarithmic instead of linear. I am still trying to figure out the algorithm to fix this.

What it looks like …

Screen Shot 2563-04-03 at 10.01.53

What it’s supposed to look like …

Screen Shot 2563-04-03 at 10.00.15



Other than fabricating the board. I’ll also be working on the synchronous web instrument next week.

Notes for parts

ATSAMD11C14 vs ATMega32U4?

Both native USB

ATSAMD11C14 (32 bit): less pins, low memory, faster, easier to solder, need J-link to program
J-link https://www.digikey.com/product-detail/en/segger-microcontroller-systems/8-08-91-J-LINK-EDU-MINI/899-1061-ND/7387472

ATMega32U4: more pins, higher memory, slower, difficult to solder, directly program
Bigger pins ATMega https://www.digikey.com/product-detail/en/microchip-technology/ATMEGA32U4RC-AUR/ATMEGA32U4RC-AURCT-ND/2774248

Other parts and lead free solder @digikey

Idea: Final Project

Presentation slide https://docs.google.com/presentation/d/1i4MryEniZhbAhFP9ErM981HA3PtvgBQy70oJrNSaqNk/edit?usp=sharing


About the MIDI controller:
It’ll actually be 12-14 separate MIDI controllers for 12-14 people. Each one is just one slide potentiometer. Each one has its own channel. This will then be played through a synchronous web platform.

The idea is to have 12-14 people controlling different slides from different physical spaces but same digital space.

About variable clock:


Let ‘i’ PCB – Finished

This week we put the Eagle file to work!

Bantam setup: http://homemadehardware.com/guides/bantam-setup/

Bantam milling: http://homemadehardware.com/guides/bantam-milling-1/

CUTTING – Cutting my first Tiny PCB – this went quite smoothly with the help of Arnab. I only had to change the bit once as the design did not require the engraving bit (I’d made the cuts as thick as possible to ease the milling and the electrical flow).

CLEANING – After cleaning with Scotch Brite, the PCB was ready to be soldered on. I made sure the copper crumbs were not blocking any of the cuts.


SOLDERING – I made a huge mistake here when putting solder paste on to the board. I put on too much solder connecting most of the LED and resistors all together! (mistake!) Of course this was cleaned once I realized.


POWER TESTING – 2 of the LEDs did not come on (top left hand corner) and I had to re-solder those.

IMG_8879 2.jpg

CODING – Finally time to upload the code. At first I had used the jig and a separate power and ground source while trying to upload code on to the PCB. This caused issues because there wasn’t a common ground. (mistake!) After changing to powering by the same Arduino board as the one uploading the code, everything worked fine.

Sensor making – I sculpted another atTiny shaped sensor using a wire to use as the capacitive sensor (hanging off the bottom of the board). ***There are 3 atTiny’s here… can you spot all of them?***

Final output – after Andy placed all of them together …


I hope my PCB works as an ‘i’!

Tiny Bugs (ATtiny Programming Jig)

ATtiny: http://homemadehardware.com/guides/programming-an-attiny85/


  • ATtiny and components attached in link
  • Neopixel
  • Pushbutton
  • 3V coin battery
  • Lego pieces

I’ve always wanted to make small electronic bugs – and surprised by how tiny the ATtiny was, I aimed to make the circuit as small as possible!

I started off by designing the characters with lego pieces I had on hand then designed the rest of the components around them.



I then started preparing for each part (unfortunately had to cut out the silicone plan due to limited time)


The jig from class works perfectly.

Again, due to limited time I was only be able to finish one. The soldering and layout on the perfboard took much longer than I’d imagined (most likely because I was very focused on making it tiny!).


Also, the pushbutton of the finished piece broke last minute and I was unable to debug it!

My lessons:

  • Plan the wirings well, test everything!
  • Design and measure everything!

Through the assignment I believe I have a much better sense of the prototyping process and will try to manage the time better next time.