In the Beginning

1. Shared interest in the idea of a Library on principal.
2. concern for grid-independent, preserved and personally accessable information.
3. Wikipedia not a bad place to start.

Overview of Modules

1. Module A : Bicycle & Generator
2. Module B : Battery & Charge controller
3. Module C : Voltage Regulator
4. Module D : Raspi, Kindle, Keyboard

System as a Whole

OG WiKiPi: Off Grid Wikipedia + Kindle + Raspberry Pi

1. Discuss & Demonstrate power flow – inputs & outputs, starting with the food a cyclist ate that day.
2. losses, power output, time required to charge battery
3. hHow long power can be provided to the system.

Technical Disection

1. Anne-Marie on schematics : build and functions of both charge controller & voltage regulator
2. Jay on Raspi & kindle.
3. Shared discussion about bicycle generator > outputs & inputs.

Design Decisions

1. Custom VR vs Inverter: Inverter is awfully inefficient and fails when battery drops under 12v.
2. Also: a. We want to learn how to do it ourselves.
   b. Cost.
3. Kindle Screen – no refresh. very low power draw.
4. Raspi – obvious. Low, low power, flexibility of full OS with linux world.
5. Bicycle vs. Solar / Wind – Control. Power input not abstracted away. The system functions both indoors / and outdoors which can’t reliably be said for solar / winds.
6. Small Battery – Sufficiently proves the Concept. and helps to keep the whole project semi-mobile.

Cost Overview

1. What it cost

Discussion on Versatility & Next Steps

1. Voltage Regulator could power phones, etc
2. Broadcasting via Pi
3. Different Pi SD’s could contain software for different communcation systems – BBS, Phone, Web, Etc

Here is the .pdf version of my in class presentation. Energy Presentation

[Generating energy]
DC motor: Voltage 24 volts. Power 250 watts. Rated speed 2750 rpm. Rated current 13.5a

In order to have the wheel-roller spinning as evenly as possible, we ran a positive current through the motor, using it as a lathe.

We then measured the voltage we could produce without any load. Bicycling lazily, Jay could produce 15 volts.

[Powering the Raspberry Pi]

We bought a 12 volts rechargeable battery that will eventually be recharged by the bike-powered DC motor. Here are the battery specifications:

Battery: enercell sealed lead-acid. 12 VC. 7.ah. Normal charge 14.4-15 OV. Stand by 13.5-13.8 V.

We built a circuit that could regulate the voltage down to 5 V using the following:

Battery -> 100uF -> 7805 regulator -> 100uF -> 1uF -> Raspberry Pi

WE used this circuit to power the Raspberry Pi

Raspberry Pi draws .500a to .700a to boot.

It took Cycling for 1:52 to fully charge three 2.5VDC Capacitors in Parallel.

A Project by Jay and me. Illustration by Jay Zehngebot.

The Context
When the tsunami hit Japan in 2011, we recalled reading  news about a hand-written newspaper.

“Unable to operate its 20th-century printing press — never mind its computers, Web site or 3G mobile phones — the town’s only newspaper, the Ishinomaki Hibi Shimbun, wrote its articles by hand with black felt-tip pens on big sheets of white paper.”

Late October 2012, Hurricane Sandy hit New York City. We were in Manhattan when the city shut down the subway the Sunday before the storm. For the whole of Monday we managed to work – with power and access to the Internet. The power went off in the evening, around 8pm.

At first it was nice; being disconnected from the entire world. We connected to another one: life without access to information. For the 4 days we stayed in the Manhattan blackout, I realized how dependent on power and the Internet we are. We had no paper dictionaries, no encyclopedia, basically no resources to learn/verify/read.

“When I was a kid, we had blackouts, and we didn’t have internet then, but it was the first time I had to face how dependent I am on the internet. Since i’ve moved to the city, I don’t have any books”
- Anne-Marie

The Project
We like bikes. We bike anyways. Post-Sandy, stated simply, we want a bicycle-powered computer.

furthermore, as we proceed towards a cloud-based network structure, we loose localized access to information, files, resources, and applications

We’re not aiming to build a gridless-internet with this project – but instead, maintain a link to knowledge. If the power goes out, we want to arm ourselves with information.

to this end, the Raspberry Pi is an exciting platform. Low-power Linux offers a number of options.

Some diy bike-powered battery projects have been put out there already. Like this one, or this other one.There is also this bike-powered cellphone charger.

We will build on those previous experiences and will try to set up a system that can power the Raspberry Pi with the lowest COH (cost for harvesting) and for the longest time.

Calculate the energy stored (in joules) in our pendulum

Here are the measurements for the pendulum David, Xuedi and I did (from a great drawing of David):

1 pound * 9.8 / s / s * (24 inch) = 2.70979711 joules

2.7 joules/10sec = 0.27098 watts

Out pendulum worked for 2 minutes, so:

2.71 joules/120sec = 0.2258 watts.

Measuring the voltage of a stepper motor using an Oscilloscope 

This DC motor has a voltage of around 3V.

Kinetic powered circuit

Rios and I built a weird thing that uses wheels to power 2 LEDs.

We used two DC motors of this type:

Kinetic powered LED Wheels