Seeing how simple it is to tap into a smartphone's power supply was really inspiring to me.
Idit Barak and I decided to work together on this project. The simple prompt, "create an absurd phone add-on" (not an accessory) was very thought-provoking, and we wanted to design something that had the right balance between absurdity and criticality, and of course, something that adhered to the essence of a Chindogu.
Brainstorm
We both came up with different ideas. Some of them were simple; a fork that plugs into your phone so you never miss an instagram post while you eat, an ambulance light to move people away, or even an inflatable bubble to separate from the outside world to be with your phone alone.
These were all fun but none really clicked with us, until Idit had a great idea.
This immediately resonated with me and we decided to do it.
Build Process
We started by identifying the main design and technical specs:
Compact
Had to spin slowly
Light enough to be held from the phone connector
Sleek and modern - Apple style
Simple to power
Had to play a lullaby song
To determine how slow has slow enough, we manually spun a piece of paper to the speed we were expecting and counted the seconds it took to do a full revolution. From this simple but effective exercise we determined that somewhere around 7 to 12 RPMs was going to work nicely. We found a nice 9 RPM that was small and worked under the 5Volt USB output.
We knew that to power the whole thing we decided to gut an existing device instead of building a custom board. We looked around and bought these USB-C fans for the phone, and thankfully were simple enough to disassemble. Once taken apart, we desoldered the motor and kept the PCB, which had a simple RC circuit.
In order to keep everything in place, we built a little support board for the motor and designed and 3D printed a custom hub using Fusion360. I used very low tolerances to keep everything nice and snug without using glue or screws.
Aesthetics are extremely important to us, so we had to make sure everything felt like it belonged. The shaft was made using a repurposed spring shaft, and we used brass 3mm-5mm couplers to put everything together.
For the mobile itself was built using one we bought at a dollar store. We cut the arms to be more compact, added a few touches and spray painted it. Idit made beautiful ornaments using a sewing machine.
Since the beginning of the process we knew that playing audio on a small IC was going to make everything complicated, so to solve that issue, I wrote a very simple website that plays a song when the add-on is connected to the phone. The code lives here.
Result
We are very happy with the way this turned out. We feel like we made something cohesive and polished, critical and well engineered.
I really liked working with Idit. Our skills, style and obsessiveness complemented each other very well.
You can see it in action below.
Introducing.... the iNap Pro
Thanks for reading