a bicycle-mounted roving detective kit for urban investigation

designer:  Ryan Lewandowski

Fastened to a bike via a shock mount,  Sherloc is a battery operated urban sensor device that records the temperature, humidity, light, and airborne particulate matter that is then geolocated with the onboard GPS device. This information is stored as a Comma Separated Value (CSV) file that can be easily mapped within Grasshopper to create parametrically driven data landscapes or surfaces for a city or site.

The device  will take readings once every 2-4 seconds. Once your trip has been completed, just press the power switch to end the recording. To retrieve the recording, unscrew the top of the box and remove the MicroSD card from the shield on the Arduino. Plug it into your computer and you have a formatted CSV file that can be opened in Excel or read directly through Grasshopper!

Sherloc also has o-ring mounts for an iPhone.  This is specifically for apps that record decibel levels and topography, but app-space contains many as-yet-unexplored regions…

iPhone attachment

inside the box


There is a constant two-way conversation between the developer, David Rutten, and Grasshopper users through the grasshopper forum, providing Rutten with first hand knowledge of the interests of people who work with this software. This special relationship with users has extended to outside developers who are encouraged to create plug-ins that expand the reach of the grasshopper platform. Expansions into territories outside mainstream architecture now include connections with database spreadsheets and tabular data available through the internet, ability to link with real-time data flows, connections to mapping platforms, connections to data resulting from energy simulations, the ability to  interface with sensors and motors to create active physical prototypes, etc.

We have used many plug-ins in this work.  Some of them, such as  hoopsnake, kangaroo physics, mesh edit, paneling tools, and tree8, add to the general functionality of grasshopper.  The plug-ins that pertain to the specific needs of this research are:

tabular data:  gHowl and LunchBox

internet connections:  gHowl, Slingshot!

real time data and active physical prototypes:  Firefly

maps and Geo:  Elk, gHowl

simulations:  DIVA, Geco

See also the Data Study and Solar Study file tree PDFs.  These reveal the plug-ins used for particular downloadable definitions.

Walk Log

Sherloc is a bicycle-mounted roving detective kit for urban investigation.  Taking transects through a city, it records GPS coordinates, light, humidity, sound levels, and airborne particulate concentrations.  This data is brought into Grasshopper through gHowl or LunchBox components where it  provides a means to visualize these wild urban energies as a medium for constructing weather. This building scale data is a key addition to the context provided by the NOAA and Weather Underground.

Here is Sherloc’s maiden voyage through some not-so-urban lawns and pastures near Batesville, Virginia.

The white framed extrusions show light level readings.  The black extrusion captures an instant of the frame-by-frame reading of the data.

sherloc’s path definition

sherloc files

local weather feeds

The Weather Underground has many associated personal stations that provide streaming weather data.  These report temperature, humidity, barometric pressure, conditions, wind direction, and wind speed.  In some areas there are enough stations to reveal local microclimates. You can create your own array of weather stations by adding to Weather Underground’s network.

weather underground rss files

Weather stations coordinates are mapped to XYZ space with a gHowl component.  The yellow cones are proportional to the wind speed reported at each station.

albemarle wind from lp on Vimeo

Wind speeds were recorded for several  Albemarle County stations on July 28, 2012 between noon and 1:00 PM.  Readings were taken about twice per minute from the weather underground RSS feed using the gHowl plug-in for GrassHopper.  Wind speeds ranged from 0 to 7 mph during this interval.  Note that these summer breezes could not be described as having a prevailing direction!

US wind

This is a simple definition that parses live wind data for Eastern US from the boy genius weather feed list.

Wind is represented as a vector extending from each weather station.  Wind is also shown as a delaunay topography. Note the sharp wind peak in Michigan! (This definition is based on a temperature map by Arthur Mamou-Mani.)

US wind definition

stockticker tutorial

Sometimes you might need a value on a website that is continually updated. This example will show how to pull a live Stock Market value into Grasshopper using the HTTP read component in Slingshot! to isolate and continually update the Apple stock value.

stockticker tutorial pdf

vacant buildings

all Baltimore vacant buildings files

grasshopper definition

This definition coordinates a jpeg image of Baltimore, OpenStreetMap geometry, and vacancy data with a grasshopper file.  Vacant buildings, with address tags, are located within the urban geometry.  Other features, such as parking surfaces, garages, bridges, tunnels and public buildings are included in this geometry.