Open Data Cam the visual data creator

Here’s an example of the Open Data Cam in action.

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Open Data Cam is currently in Alpha Testing

About Open Data Cam

'Open Data Cam' is a tool that helps to quantify the world. The best thing about it: You can make it yourself! With computer vision 'Open Data Cam' understands and quantifies what it sees. The simple setup allows everybody to become an urban data miner.

Why do we need this?

'Open Data Cam' can help cities become smarter. One way of understanding smart cities is the combination of urban areas and emerging technology. 'Open Data Cam' can help cities (via its citizens, institutions, scientists and decision makers) to make more sense of its surroundings, by using data points created by 'Open Data Cam'.

Examples

The idea behind 'Open Data Cam' was to create a free, easy to use platform for detecting objects in urban settings. Creating data through real time detections can change the way we make decisions and perceive our urban surroundings. With these tools at hand, it’s up to you what you want to quantify. 'Open Data Cam' might help you automatically turning traffic into data or might even turn mobility into a game. Check out our use cases.

Automated Traffic Survey

The obvious use case of 'Open Data Cam' is to count vehicles at any given location. The gathered data can be used in traffic engineering. For example for validating traffic models, learning about traffic composition by vehicle type or validating other counting methods. But we’re also more than curious about what you will do with your 'Open Data Cam' — shoot us a line with your idea!



GitHub Repository

Traffic Game

‘Beat the Traffic’ is our version of traffic counting. Based on the technology we use in 'Open Data Cam', you can create a mobility wonderland in cities around the world. Players can magically turn traffic into unicorns, rainbows and driving trees. Your highscore will be converted into how many busses would have been needed to transport the cars you have clicked, addressing mobility challenges of our time.



Beat the Traffic

How does it work?

'Open Data Cam' is a video camera attached to a mini computer running an interface and counting detections of the video stream. A peek under the hood shows the heart of 'Open Data Cam'. A Jetson TX2 board running on a graphical processing unit (GPU). The GPU allows it to process many parallel threads at once, perfect for image analysis and video processing.

While the heart is pumping data, the brain of 'Open Data Cam' is running YOLO — an object detection library. YOLO is based on machine learning and is trained to detect objects in pictures and videos. The attached camera feeds YOLO with a video, YOLO then outputs all objects in every frame.

By accessing the interface of 'Open Data Cam' users can reach the honey pot of data, created by the system. It lets users specify which areas of the picture YOLO should count objects in. Finally the export function allows users to access the detected data points and use it in any thinkable way.

All material and tools you will need to assmble 'Open Data Cam'

How do I make my own?

The best thing about 'Open Data Cam' is that it’s designed to be a DIY project! Giving everybody the chance to create data, where they think it’s needed. A shopping spree and DIY-afternoon later, you’ll be all set to quantify the world around you.

Materials needed

One sheet Polypropylen (250×70cm)
One sheet of cardboard (23×27cm)
Small zip-ties, kind of a lot
Scotch tape
Duct tape
E27 lamp socket (with removable top)
Nut 1/4” (for tripod)
Strap
Some foil or plastic sheet (approx. Ø 5cm)

If you want to use a battery

Battery Li-Po 3C (11,1V) (choose the mAh you need)
D/C Plug 5 mm
Thick cable (2 wires)
Connector for battery
Stripboard
Battery alarm buzzer
Diode or 10Ω resistor
100µF capacitor
Latching relay
Push button
PCP header strip
Battery Charger

Tools needed

Cutter knife
Cutting mat
Ruler
A hole punch or perforator
Some glue (we used hot glue)
Pliers
if you want to use a battery
Soldering iron and stuff
Fiber tester
Li-Po battery charger
Tools, equipment and material you'll need for the next steps of assembly.

Hardware Instructions

1

Download folding map
Download instructions

General instructions

Print the folding map onto regular A4 paper (or letter size) sheets and tape them together along the marks to get the actual folding map. Make sure you clicked on „actual size“ while printing. You should end up with five folding plans, one consisting of six sheets, one of two and three of one each. Tape the instructions onto the materials and start cutting them out. The solid lines are cut lines while the dashed lines are folding lines. Cut them as well, but be careful not to cut them fully through, otherwise the case will not be splash proof or even hold. While folding, do it slowly and carefully to not break the material. It should become solid white on the edges, then you know it went well.

For the holes use a hole perforator or simply cut them out to fit a strap holding together at the end.

Tape the printed sheets together along these marks

Folding Map
Print and align the folding map.

Cut out the materials along the solid lines

Slice me nice.
Cut out the materials along the solid lines

You can use a hole perforator for the holes

Holes for holds
You can use a hole perforator for the holes to strap everything together at the end

2

If you want to use a battery

Battery Safety

Since Li-Po batteries are likely to break if over or undercharged, it is necessary to keep the battery from doing so. For loading there are already perfect chargers to buy. To prevent it from being undercharged, a low voltage battery cut-off does the job. This tutorial explains it really well how to build one yourself: Battery Protection Curcuit Cut.

We made some small adjustments by adding plugs to either cable to make it easier to change the battery later. Put your built PCB in a bag to keep it isolated from the rest and to prevent a short circuit on either boards (e.g. you could use one of the wire zip-bags of the Jetson TX2).

3

Cardboard Inner

The inner element on cardboard as well as the bottom element for the polypropylene have marks for holes for the ports of the Jetson TX2, just cut the ones out you need to keep it as closed as possible. In my our this was the DC, USB and Antenna ports.

Cut the camera element depending on the webcam you use. The spot is marked, where the lens center should be, just cut parallel to the dotted lines wherever your webcam holder is located.

Glue the tripod nut in place (we used hot glue, not really beautiful, but does the job). The hole has the size of the outer nut elements so it should not be able to turn.

On folding up, the hatched areas should overlap. This is where you should glue/tape/zip-tie them together. Put the webcam onto the socket so that the lens is horizontally centered to the axis mark and put the wire around the wire-holder (keep in mind to leave enough wire to still plug it in later). Fixate the camera using some zip-ties.

Cut up the card board and attachment holes.

Board & Cam mount
Cut up the card board and attachment holes to mount the Jetson board

Once it's strapped up and cam is attached you cardbopard should look like this

Camera mounted
The camera is mounted on the card board, also the Jetson board will go in here.

This is how we attached the 1/4'' nut for the tripod

Tripod Nut
This is how we attached the 1/4'' nut for the tripod

This is what your battery-overcharge device should look like (Step 2)

Battery Overcharge-Device
This is what your battery-overcharge device should look like (Step 2)

4

Assembly

Once plastic and cardboard is cut, it comes to putting everything together. The labels at the holes should help you to locate where everything belongs.

Start with the lid, to understand the concept. Simply fold the sides so the holes lie on top of each other, then put a zip-tie through the holes and pull them tight.

Now the tricky part. Fold the big outer piece like a bag or box of cereals. Fold it up where you made the cuts, the paper folding plan should resemble the inside of the case. Two parts should overlap now, one slightly shorter than the other. Keep in mind to leave the bigger part (the one with the four holes at the top) on the outer side.

Put the bottom part into the main part, having the holes on top of each other. Then, again, pull the zip-ties through and tighten them. On some holes there should be up to four layers of polypropylene.

On one of the upper corners lie also two holes on top of each other. Tighten them as well.

If the two polypropylene layers are assembled, insert the previously built cardboard inner element. Same here, put a zip-tie through the two double holes and pull them tight.

Finally put the handle with the four holes on the outside of the four holes of the main case and combine them. To be safer regarding the splash proof aspect, put some duct tape on the holes from the inside.

The lid after it's been folded and zipped

Start with the lid
To get a hang of how assembly works, start with the the lid. It should look like this after it's been folded and zipped.

The bottom and the sides assembled and zipped

Fold and zip the box
The bottom and the sides assembled and zipped should look a little like this.

The top and and the bottom parts zipped together

Close up of zip connectors
The box should fit together like this to protect it's content.

Put the lamp socket through the hole in the case and fix it with the lampshade holders

Peek-a-Boo
Put the lamp socket through the hole in the case and fix it with the lampshade holders. This is where the camera should peek out.

Take the lamp socket and put away the inner elements, since you will not need it. Put it through the hole and use the lampshade holders to fix it onto the case. Adjust the distance to the camera as close as possible. If you see in the later picture some vignettes you do not want to have, simply cut, saw or sand the socket down a bit, but it will probably not affect your traffic tracking.

For splash safety reasons you could also cut out some plastic and insert it in the socket (e.g. from the packaging of your webcam). You could also take some kitchen foil and a rubber band and put it around.

Insert your battery cut-off element. Put the D/C wire through the battery wire hole and just place the rest inside the case.

Put in the Jetson TX2 into the case. The metal distance-holders on the PCB should fit in the cardboard slots on the back to hold it tight in place. Plug in the wires and antennas from the outside.

Finally take the lid and place it on top. The handle should go through the slot in the lid. It will hold in place when you insert the little notch into the slot in the handle.

Bonus: Insert a strap through the vertical slots in the handle to hang it on poles.

An additional element will allow to hang the box on poles

Bonus: The Hanger
An additional element will allow to hang the box on poles.

The Jetson TX2 inside the cardboard case

Snuggle the Jetson in
The Jetson TX2 inside the cardboard case should fit like this.

Place the lid on top, the handle goes through the slot

Top it off.
Place the lid on top, the handle goes through the slot

This is how the bottom of the device should look like with all elements fixed

All fixed and ready to go
This is how the bottom of the device should look like with all elements fixed

Software instructions

1

General instructions

Once you’ve built your traffic cam you’ll want to start counting traffic right away. That’s why we’ve created an open source version of what we built to make the cam work. You can find the installation guide on GitHub

The software running on the jetson board will allow you to draw lines into the video stream. As objects cross this line, they will be counted, no matter in which direction. Add more lines to count on multiple spots. After finished you can export the data by hitting the export button. All data processing happens locally on your Jetson board.

Draw lines
As objects cross this line, they will be counted

Export data
Export your collected data as csv

2

Step by step

In the repository you'll find everything you need to create a bootable Jetson board running the 'Open Data Cam' interface.

To get your Jetson up and running you need to connect it to you computer and get into the Dev mode by using JetPack, which will install linux and all dependencies. You can find a detailled guid on how this workes in the README of our repository



GitHub Repository

Credits and People

Concept & Idea
Benedikt Groß, Markus Kreutzer, Raphael Reimann

Software Engineering
Thibault Durant, Thomas Derleth, Marco Biedermann, Joey Lee, MESO Digital Interiors

Product Design
Olivier Brückner

Video Documentation
Raphael Reimann, Thomas Thöne, Olivier Brückner