Purpose: To explore alternative networks and engage in current discourse by creating a project for raspberry pi + mesh network.

Concept: Build a mesh-capable, mobile Raspberry Pi with an accompanying should strap/holster for easy portability of the pi as well as a simple chat application.

Target:

• People who are already aware of network infrastructure.
• People who are code literate.
• People who want greater online privacy.
• People interested in exploring alternative communication.
• People who care about preserving democracy.
• Urban explorers.
• Tech hobbyists/enthusiasts.

Research: Lots and lots of research.

• Mesh networks/communities/software

  • http://subnodes.org/ (mesh)

  • https://github.com/WachterJud/qaul.net (mesh)

  • http://www.open-mesh.org/projects/batman-adv/wiki/Quick-start-guide (mesh)

  • https://nycmesh.net/ (mesh)

  • https://code.google.com/p/fabfi/ (mesh)

  • http://www.backslash.cc/ (mesh)

  • http://radicalnetworks.org/ (community)

  • http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man8/hostapd.8?query=hostapd&arch=i386 (software)
  • http://www.thekelleys.org.uk/dnsmasq/doc.html (software).
•  Tutorials:
  • http://elinux.org/RPi_USB_Wi-Fi_Adapters (list of all raspi supported dongles)
  • http://raspberry-at-home.com/hotspot-wifi-access-point/ (tutorial on raspi as AP)
  • https://learn.adafruit.com/setting-up-a-raspberry-pi-as-a-wifi-access-point/overview (another tutorial on setting up raspi as AP)

  • https://bogeskov.dk/UsbAccessPoint.html (for rtl8192cu drivers)

  • https://nims11.wordpress.com/2012/04/27/hostapd-the-linux-way-to-create-virtual-wifi-access-point/ (hostapd tutorial)
  • https://nims11.wordpress.com/2013/05/22/using-hostapd-with-dnsmasq-to-create-virtual-wifi-access-point-in-linux/ (dnsmasq tutorial)
  • http://hackaday.com/2012/11/14/mesh-networking-with-multiple-raspberry-pi-boards/
• dongles used/tested

  • TP-LINK WN725N (did not work)

  • OLIMEX rtl5370 (produced SSID, no connection)
  • LB-Link 802.lln wifi usb (produced SSID, no connection)
  • TP-LINK WR702n (purchased, did not test)
• Database used:
  • http://redis.io/ (for raspberry pi) because it runs locally, requires no connection to the cloud or star network service.

Design Process:

• Iteration 1 – http://portfolio.newschool.edu/demcg318/2015/11/02/portable-meshpi-prototype-1/
  • 
• Iteration 2 – http://portfolio.newschool.edu/demcg318/2015/11/02/portable-meshpi-prototype-2/
  • 

• Iteration 3
  • Moved away from building arm-mounted raspberry pi holders towards something more like a detectives gun holster. The shoulder strap also comes with an attachable 21w solar panel and a small satchel/backpack to carry various accessories (dongles, batteries, hard drives, replacement parts, etc…)
  • 
  • 
  • Benefits include:
    • Greater distribution of weight
    • concealable/not as conspicuous
    • modular. other items/accessories can be attached as necessary.
  • Some problems:
    • weight issues. The more components you attach to the back of the holster, the heavier it gets and the more it sags in the back.
    • cardboard construction. weak, prone to breakage.
    • usb power cord attached to raspi is a tad awkward/prone to tangles.
    • case for raspberry pi needs more thought/design
  • Future iteration:
    • leather or synthetic strap construction
    • work with fashion designer to sew and work out sagging issue
    • construct a better satchel. Experiment with weather proof materials
    • experiment with raspberry pi case design. Move beyond cardboard.

Challenges:

• Setting up mesh on raspberry pi. Kernel drivers aren’t fully supportive of ad-hoc mode.
• wifi dongles get very hot.
• creating chat history with Redis database and pulling history in order to populate the webpage whenever a new user joins.
• sewing – I am by no means skilled in any way at sewing. I have minimal experience and definitely need to find tutorials or seek assistance.

Conclusion/next step:

• This project required lots and lots of research on the the topic of networks before I was able to start engaging with the topic through a project. Researching all of this stuff confirmed my ignorance on the topic, but also generated lots of interest. When asking People about my engagement with mesh networks,  they saw lots of value in the project, however, many weren’t entirely sure what kind of project could be made, other than instantiating a mesh node. Perhaps a future project might involve questions like: “how can I bring awareness and adoption of mesh networks to more average internet users?” or “What sort of applications could I build that would be exclusive to mesh networks? How could such applications be used to generate interest and adoption?” According to my ethnographic research, people were hesitant to join because it only works if many people are on it. People also weren’t absolutely sure that mesh networks are the solution to their privacy problems. So there are lots of questions for future engagement and I think next steps would be to dive into the communities already established around mesh networking to see what’s going on and how I can help.

Google slides presentation:

• https://docs.google.com/presentation/d/1CGuNh5DNDDObzshei2RHpZrjphAnT8JmWWBQhe7ZH8s/edit?usp=sharing

Link to Github repo:

• https://github.com/deevolutionism/meshChat

edit: pictures.

Prototype 2 is also constructed form cardboard. This time, I attempted to solve some of the problems of the initial prototype. This model features a removable/attachable case that houses the raspberry pi. The case can be lock into place. On the bottom, a 10k mAh battery is housed in order to balance the weight of the arm.Here you can see that the lid is now unobstructed and can be fully opened. The lid is also closed and sealed with velcro as apposed to a simple cardboard slit. The raspberry pi has its own independent case which allows greater mobility, portability, and protection for the pi. The case can be locked into place on the main arm construction via a pulling/hook mechanism. The mechanism is simple and effective. This prototype is far from the end product. Even though this one was properly balanced, it was cumbersome to wear. Additionally, if I moved my arm down to my side, it would easily slip off despite using buckles for tightening. The practicality of this gauntlet-like construction has been severely hindered by the size and weight. Though the location makes it easily accessible you are still limited to interacting with the pi using the opposite arm. In a future prototype I may experiment with a clip-on attachment so that you can place it on a back pack or wear it on any sort of strap, similar to how police wear radios on their chest. This will free up both hands and be far less encumbering. Future material construction might be leather, tarp, or 3D printed material  in order to make it waterproof/resistant to weather.

Prototype 1:

The first physical cardboard prototype of the raspberry pi portable mesh networking device. This one sits on the arm for easy and immediate accessibility. The Raspberry pi is housed within this case. A TP-Link WR702N sits on top of the lid. A batter is placed on the back. Finally, the whole compartment is strapped to my arm.

The lid can be lifted up to reveal the raspberry pi. A touch screen eliminates the need for a keyboard. At the moment, opening the lid requires quite a bit of effort – though it is quite secure. When opened, the raspberry pi is loosely seated and is prone to falling out of the case. No ledge, screws, or adhesives hold it in place. A battery pack is also located on the hind portion of the case. This prevents the lid from opening all the way which can be annoying when trying to use the touch screen. Additionally, the extra weight of the battery made the entire configuration top heavy, which frequently caused it to roll around my arm. Accessing the HDMI port and mini-usb charging port was also difficult because they were blocked by another wall of cardboard.

 

Ultimately, this initial prototype construction had many flaws. Perhaps the most severe flaw was its tendency to roll around on the arm. This made it practically unusable unless you constantly held it in place.

In order to fix this, I propose straps be used to tighten the container to the arm. Additionally, the battery will need to be either removed or placed below the forarm, as if hanging, in order to serve as a counter balance to the weight of the pi.