Paper Lamp by Yulia Besplemennova(z3406397)
SDES-3107 Arduino Assignment
Concept Background As a product designer I am interested in adding some interactivity to the objects surrounding us. Unfortunately now people perceive electronic technologies in a strange way. “Normal users” are sure that it’s not easy to understand and they could never learn how some objects work. I also don’t like the contraposition of technology and crafts which people have in minds now, when they think of electronic objects as sleek futuristic ones and crafted as made by hands with love. I would like electronics to be more “homemade” and understandable for others, so I’m very inspired by the projects like Instructables and MIT High-Low Tech group. And having some experience with Arduino I wanted to try also Attiny controller as it gives additional compactness and increases the application possibilities.
So generally I took from two ideas: the paper piano from High-Low Tech http://hlt.media.mit.edu/?p=1376 and a mood-lamp from Instructables http://www.instructables.com/id/Color-Changing-Night-Light/#step1, both using Attiny.
Process
The initial idea was to create a pop-up lamp in size of the postcard with the sliders to change the color and brightness, but then I simplified it a bit.
I started with programming the Attiny-85 with Arduino board. Following the instructions from tutorial http://hlt.media.mit.edu/?p=1229 After getting sure that it works I had to change the sketch to make it work with potentiometer which was made later from resistive paint. What I had to change was adding the correlation between the delay in microseconds for which each of the LEDs was on and the sensor value.
For this was introduced the “balance” variable which changes depending on the voltage from the analogue input and affects the outputs. The initial sketch can be found here http://www.instructables.com/id/Color-Changing-NightLight/step2/Programing/ and the final is in the project folder. After testing it on the breadboard I had to start assembling the paper circuit.
The working principle here is the same as in the paper piano tutorial. The “potentiometer” is made of one stripe of conductive material (which is the copper tape in my case) and another is from resistive paint made of graphite and PVA glue. The only difference is that instead of making the “keys” I use the slider.
On the left is the “sensor�, the power and ground are connected to the resistive part and the value is read from the conductive stripe and goes to the pin of Attiny. The sliding paper has the copper tape from the inside. Two RGB LEDs have the common cathode so it goes to the ground and other three pins are wired with the microcontroller. Unfortunately copper tape can’t give the normal contact even from the sticky side, so I had to solder the components to it. The small 3V battery is used for the power.
Schematically the circuit is the following:
After all I decided to make the look of the postcard more handmade and decided to put the writings with the watercolors instead of just the printed gradient of the rainbow.