Energy Wk 6: Budget + MVP

1.) Energy Budget

Google sheets of energy budget: here

Screenshot 2019-03-14 00.59.05

2.) Solar Panel:
I measured open circuit voltage, short circuit current

I also charged my lithium ion battery with the solar panel.


3.) MVP: Power temperature sensor with solar panel


4.) Try Feather RF:
still figuring it out


Helpful resources for energy budget:—part-ii-the-art-of-the-power-budget

Helpful resources for Temperature Sensor:

Helpful resources for Feather RF:

Light Wk 6: Observation

chelsea market light observation

03/03/19, Sunday @ 11:35AM
Chelsea Market, Manhattan, NY

From the color, the form, the light that is cast, it is clear that there are over 3 different types of light sources from this point of view. On the right, the warm light is coming from the timeless incandescent bulbs. In the middle of the roof there are rows of LED (I’m pretty sure?) lamps hanging from the ceiling. These larger lamps are slightly cooler than the incandescent bulbs, but they might not be cool white? Perhaps just in comparison, the LED lamps look as though they are a cool white. The colors on the glossy but banged-up wood panels make this color distinction especially obvious. From the candle project, I know that the black floor boards make for an especially reflective surface.

On the left there is natural light shining through. I remember the day being sunny, but sometimes overcast. Therefore, the bright blue is definitely coming from the sky. Hiding underneath the lower roof of the shops on the right are what looks like christmas-type lights being strung.

This scene is lovely for it’s various light sources. The beams and pipes on the roof make such beautiful shadows on the roof.

Light Wk 6: Key Sconce



Key Sconce Interaction Test from Emily L on Vimeo.

Final code: here

Final interaction: 

1. if key is on handle: fade light on, play on melody
2. if key is not on handle: turn light off immediately, play off melody
3. if key is on handle, but room is dark: turn off light


This has been a bumpier week with sensors and the Arduino boards. My Arduino uno stopped working for some reason, so I switched over to the Mega. I then realized the Mega was too big for my sconce enclosure so I then switched over to the Uno.

I also changed between 3 different type of sensors (and at some point even tried copper plates/tape) before finally sticking with the force sensing resistor. I switched around so much because I realized the touch sensors wouldn’t work with my wood on wood, wood on metal mechanism – it only reacts to touch. In hindsight, it is obvious that the capacitive touch sensor (both the one with the button on the sensor and the breakout version) would not work for a non-human touch. See my (sort of) step-by-step process to figure this out.

a.) First I narrowed down my light choice to be a chip on board, instead of Phillips Hue light bulb or high watt led.


b.) I tried out my circuit with a breakout capacitive touch sensor. A whole day was spent figuring this new sensor out because I needed to review the I2C information from Intro to Pcomp. There was a learning curve with this “smarter” sensor. I didn’t end up using it because I realized it doesn’t work for keys. *The capacitive touch sensor will only register as a “touch” if a person’s is holding the key.


It works with hand touch, but not with metal touch.


c.) All the while I have been fabricating the box using the CNC. See the full fabrication process in my subtraction blog post.

Photo here of the final box, sanded and waxed.

only box with holes

I then assembled the light fixture together. And eventually assembled all the parts. For the light fixture I ended up not using the socket I had bought because the COB was too far up in the globe. This caused only half of the fixture to be illuminated.

Switch mechanism was also assembled and full documentation can be seen in subtraction blog.


d.) After realizing that both touch sensors would work, even with the switch mechanism. I switched over to a Force Sensor Resistor. Circuit with that below.


After finalizing the circuit, I soldered it.

e.) I then put all the parts together: mechanical key hook switch, the pcb, the arduino. From doing this I realized how little space I had in the enclosure. The force sensor is a difficult sensor to fix properly and solder other wires to. I ended up giving it it’s own breadboard close to the switch so the little pins it has doesn’t constantly fall off.

f.) The dc adapter also had to be cut and soldered for multiple reasons. One of them being I wanted to use the white wire so that when it hangs on my white wall, it would not be too noticeable. Secondly, I didn’t want my arudino usb connected to my laptop. So, there needed to be a way to charge both the arduino and the 12V light with the adapter.

The power of the adapter was cut and connected to both the power of the dc jack plug and the power of the COB.


g.) Last thing was putting it all together and adding the back panel for the hooks.



Helpful resources I encountered for specifically the capacitive touch sensor portion:





Subtraction Wk 6: CNC Final

See final with all the interaction and light fixture in the light blog.

For my second attempt at joinery, I needed to redesign the dimensions so that the joints fit well. This took 3 separate attempts to get right!


1.) First attempt using new dimensions of just a rabbet joint.


b.) The CNC worked well enough but the rabbet joints were off. The pocket size was not enough for the front panel, so the pieces didn’t fit well. Below are all the parts of version 1 of the sconce enclosure.



c.) An issue midway through cutting was that the bit would fall off. I think this must have something to do with the depth at which it was cutting. Another reason is that the colette is potentially getting loose.


d.) Round 2 begins! Each round I changed the pocket depth cut slightly to see what would work best for the rabbet joint.


e.) A version 3 set was made. I think between all the sets version 2 and 3 were okay. None were perfect, but after 3 versions I needed to choose.


f.) The handle for the key was made by hand because the parts were too small for the CNC. When using the CNC for something this small, the vacuum would accidentally suck up the piece.


g.) Parts were glued together. Clamps were used.


h.) Sconce enclosure is glued and sanded! Yay!


i.) Next, I worked on the key handle mechanism and it’s enclosure. These parts were all hand cut with the band saw and sand blaster.


j.) I used the drill bit to make a pocket for these tiny 3/8″ ball bearings for the rod to go in. The ball bearing is helpful for smoothly rotating the rod that the key handle sits on.




k.) My sconce also includes a photo resistor so that when all the lights in the apartment are turned off the light would also turn off. This small hole was made with a drill press then expanded slightly with a chisel.



l.) I waxed the enclosure.


m.) I put all the light and electrical components into the enclosure.


n.) Last touch, I glued the screw piece to the back of the enclosure for easy mounting.




Final in this post. 


Energy Wk 5: Solar

Measure the power used when the platform running different operations. They will be the basis for an energy budget for your project.

  • So, I ran into issues with using the 6V solar panel, I didn’t have screw terminals nor the right jack on hand.


  • As an alternative, I decided to solder my own small solar panel into the dc power and ground pins.


  • Soldering time! This is not my own capacitor so I didn’t want to cut the pins off.



Helpful resources I stumbled upon as I was figuring this out:

Subtraction Wk 5: Joinery

CNC fun continues! The joinery I worked on this week is for a sconce lighting fixture. I tried out the rabbet joint to fit my pieces together. As usual, I ran into some issues. This time most of my issues were because I only have a 1/4″ bit but many of the joints required a smaller bit size. The joints became too rounded to properly fit together. This all requires some redesign. Nonetheless, I do think I’m getting better at the CAD – CAM – CNC process! Hope I didn’t just jinx it.

  1. First phase was doing a cardboard mockup. Then I did more accurate drawings for the dimensions.



2. I used Vectorworks to make the 2D files first. Then brought it into the CAM software.


3. Screwed down the wood to the spoil board.


4. Brought the files into the CNC software. Started cutting after zeroing.


After cutting, I realized that the joints that I had designed for the side panels were way to small for my bit. This means all the joints were rounded. So I need to figure out a way to create the joints without having rounded corners.

Back to the drawing board!

Light Wk 5: Sconce (wip)

I’ve decided to execute the key sconce idea! This also includes finalizing the interaction:

a.) if key is on handle:

  • turn light on
  • play tune on speaker
  • animate light brightness to match with tune

b.) if key is not on handle:

  • turn light off

c.) if key is on handle, but room is dark:

  • dim light so it is a night light


Steps I took: 

a.) Touch sensor with lights turned on. Code here.


b.) Melody combined with touch sensor and lights. Code here.


c.) Trying out ATtiny chip: Ran into issues with burning it.

d.) Fabrication side of things can be seen here:

* Writing a note because I always get stuck with timing in arduino:
– To have the beep last only 2 seconds even when touch sensor is pressed, use a counter.
– Example psuedo code:
// if button is on
// counter ++
// if counter < x time
// perform function
// else stop function
// else counter = 0

Helpful Resources: