19 May

Smart Green Roof Project: Chapter 3

The roof has grown—SLA Beeber students wrapped up version 1.0 of their Smart Green Roof model at the Fairmount Water Works this month, completing the project by creating the storage layer and planting sedum. The storage layer—made of brightly colored plastic pieces beneath the soil (constructed from Locktagon toys)—is designed to hold water as it seeps through the soil and through a filter fabric.

What makes this a “smart” model are the sensors designed to monitor how this miniature green roof uses and stores water. Soil moisture sensors and a temperature sensor can inform us about plant health; and an ultrasonic distance sensor looks down an observation well to gauge the level of water in the storage portion of the model. The data can be seen on an LCD display, and all of it is powered by a solar panel. The empty compartment in the lower right part of the model will someday house a pump that can irrigate the plants on demand. (That’s version 2.0 of the model.)

In April, the Smart Green Roof team brought the model to the Philadelphia Science Festival, where we demonstrated how green roofs work and what they do: capture stormwater, reduce the urban heat island effect, and save energy by insulating buildings.

This week, we finished with a trip to Villanova University to check out the green roof on top of the college’s CEER building. Because Villanova researchers have also outfitted their green roof with a variety of sensors and irrigation devices, it is very much like a scaled-up version of the Smart Green Roof model.

22 Mar

Smart Green Roof Project: Chapter 2


This spring, greenSTEM is delighted to have guest bloggers! We’re working with the Fairmount Water Works and high school students from SLA Beeber to create a smart green roof model using microcontrollers and sensors.

After researching green roofs and getting some exposure to Arduino programming, we are beginning to build the model. Kevin Magerr, an engineer with the Environmental Protection Agency (EPA), delivered the skeleton of the model: an acrylic box with different compartments for the soil/plants, electronics, and a water pump. Also joining us was Cara Albright, a PhD candidate with the Villanova Urban Stormwater Partnership. These experts helped guide the model’s development.

  • “We got our green roof model and it looks amazing. Kevin, an EPA engineer, and Cara, a student at Villanova University, helped us make plans for our green roof model.”—Tyheim


One way to monitor the effectiveness of a green roof is to look at how much water it can hold. Above, we plan to install a tube that acts as a well in the system. It will fill up with water and we can use an ultrasonic distance sensor to capture the level of water in the well. We talked about how the sensor works—it uses sound signals that bounce off the surface of the water, operating much the same way a bat uses echolocation to detect its surroundings—and experimented with different sizes of tubes to determine the most accurate measurements.

Terrance and Tyheim also began to wire an LCD display that will create a readout of the water level in real time. All of our prototyping is done with breadboards and jumper wires; once all the elements are in place, we will solder these circuits together to be able to look at multiple sensors and displays: water level, temperature, and soil moisture, for example.
Helpful links:
Ultrasonic (ping) sensor tutorial and code
LCD display tutorial and code
05 Feb

SIM City: Philly Students Debut Sewer Inlet Monitor at STEM Competition

MBACS_2016

Move over, Ninja Turtles—there’s a new hard-shelled, talkative superhero in the city sewer system. Meet SIM (Sewer Inlet Monitor), defender of our rivers and streams, guardian against street flooding, and unrepentant tattletale. SIM texts or emails when sewer inlets become clogged with trash, alerting the public when cleaning is needed.

Yesterday, five 10th-grade students from Mariana Bracetti Academy Charter School presented SIM at the regional portion of the 2016 Governor’s STEM Competition. At the School District of Philadelphia, judges from the Mayor’s Office of Education and Drexel University awarded the students first prize; they will advance to the statewide competition in May to represent Philadelphia. (Full disclosure: They faced no competition from other teams. Full disclosure, Part II: These students worked after school, they came into school on days off, they worked after full days of standardized testing, so … they won and they earned it.)

MBACS_SIM

The photo above shows SIM on the outside; it’s camouflaged, waterproof, and rugged enough for, well, a sewer inlet. The device’s inner workings are, for now, a trade secret. (We’ll open-source the project shortly after the state competition.) The Mariana Bracetti students worked with Philadelphia Water‘s greenSTEM project to research a community problem (excessive trash near the school, right across the street from Frankford Creek), learn basic coding and circuit-building, develop a prototype, test, and revise the final product.

In addition to presenting SIM to the judges and conducting a succesful live demo, the students were issued a Project in a Box challenge: given 30 minutes and a mystery box of materials, they had to work as a team to solve a problem. The challenge? Build a paper airplane to fly a raw egg into the center of a target, using a short list of materials (tape, tissue paper, glue, etc.). Here’s how it went:

MBACS_eggplane

Submit your egg jokes/puns in the comments section.

Thanks to the School District and the judges, as well as Mariana Bracetti teacher Lauren DeHart and Drexel/greenSTEM coding mentor Sean Force.

20 Jan

TechGirlz Tackle Arduino

LED_smiley

On Saturday, more than 20 middle-school girls gave up an unseasonably sunny afternoon to hack with Arduinos. Philadelphia Water’s greenSTEM project hosted a free TechGirlz workshop at Moore College of Art to explain how low-cost electronics and sensors can be used to help the environment, improve our cities and neighborhoods, and connect the real world to the virtual world.

We hit the ground running by setting up with Codebender, a browser-based Arduino programmer that takes much of the pain out of installing software, drivers and libraries on two dozen different computers. We quickly moved to a modified version of the Arduino blink activity and then tackled an art project: programming designs onto a 16×32 LED matrix sign using an x,y grid, geometric shape codes and color codes. This was hard work—many lines of code were written with intense focus.

LED_desert

Thanks to the girls for attending, to our TechGirlz volunteers, and to Moore College for providing the space.

27 Apr

Thinking Outside of the (Cardboard) Box

Ninth grade students at Science Leadership Academy’s Beeber campus began the challenge this week of creating their own solar-powered, video-capturing, soil-moisture monitoring bird houses—and maybe even a few bat boxes. Each unit will be equipped with its own Arduino/Raspberry Pi  device that will harness the solar power and use WiFi to transmit soil-moisture data and a live “peep show” (get it, because they’re birds?) courtesy of the infrared camera, allowing students to observe the birds inside. As if all of the technical aspects weren’t enough to consider, the students also have to be aware of what kind of birds they’re building for, and choose their houses’ specifications accordingly.

So this week, in becoming aware of their tenants, the students crafted cardboard to scale models of their birds of choice with the help of Alex Gilliam, director of the organization Public Workshop (which collaborates with youths and their communities to help them shape the design of their cities through workshops and leadership programs). And check out the results!

Photo credit: Matthew Fritch

Here we have a few American Robins, a few House Sparrows, and one American Chickadee. Some students also scaled cardboard models of starlings, bluebirds, and bats.

Gilliam encouraged the students to account for both the size of their birds with their wings at their sides and fully spread. They’re each taped to a cardboard sheet inscribed with pertinent information—things like diet, preferred habitat, and how they prefer to nest.

Next week the students will start modeling cardboard prototypes of their birdhouses/bat boxes for their cardboard creatures in order to get the designs perfect for the final products.

16 Apr

Welcome to the Matrix

SLA_LED_plant

In our last post, we detailed how soil moisture sensors and datalogging are not exactly the cure for dead plants (or neglectful students). The next step at SLA Beeber was to give students blindingly bright visual cues as to when their plants required watering. Along with taking soil moisture readings and determining a wet or dry state, students programmed their own designs onto an Arduino-powered LED matrix. Remember Lite-Brite? It’s kind of like that, except it’s coded in Arduino using an x-y coordinate system, geometric shape commands and color codes. Students began by sketching their designs onto a 16×32 grid, then breaking the grid into rectangles, lines, and pixels as lines of code:

Feed_LED

Adafruit has an excellent tutorial on how to wire this to the Arduino and program it. We put the display inside a Pelican case to keep it dry and set it up in the school’s hallway, where one can only hope the plants’ occasional pleas for water will catch someone’s eye.

08 Dec

Fairmount Water Works Sensor

Now on display at the Fairmount Water Works—a simple soil moisture sensor with an LCD display to keep track of a plant’s watering needs. This is just a first step in developing some really interesting ways to monitor plants and get feedback on plant health. Working with two 10th grade students at Science Leadership Academy, we’ll be investigating how to use visuals, audio, and Twitter to communicate environmental data.  (We’ll also be investigating why we didn’t put the electronics in a waterproof case, because what’s more awesome than an unprotected circuit board next to a plant that’s being watered?)

This setup uses an Arduino Uno ($25), a Grove base shield ($10), a Grove LCD display ($14) and a Vegetronix VH400 soil moisture sensor ($37, though you can find soil moisture sensors for under $10; we like the performance of the VH400). The Grove shield stacks on top of the Arduino and lets you use snap-in wires to connect sensors and displays. The Arduino code is after the jump; it’s basically modified code from the Grove website.

We did a rudimentary calibration of the soil moisture sensor and got readings for the sensor in air, in dry soil, in wet soil, and immersed in water. From those measurements, we estimated readings below 200 would probably indicate the plant needs watering. It’s not an exact science, but we’ll learn more about what the sensor output means as we go along.

Read More

15 Nov

Re-branding: “Root Kit?! Not on my network, pal!”

root kit complete

This is our physical product. We are calling it a Root Kit. The Root Kit is a do-it-yourself environmental sensor kit for schools to be able to wirelessly monitor rain gardens and other vegetation in real time on the web. On the left is the data receiving unit; it sits inside the school and receives sensor data from the object on the right, the sending unit. It is contained in waterproof case and is equipped with a temperature sensor and three soil moisture sensors. The soil sensors get buried in the ground and almost act as roots. This is the Root Kit.

Now, tech-savvy people will howl at the name, because a “rootkit” is a dirty word among IT and network security professionals. You see, a rootkit is techspeak for malicious software that invades and attacks servers and computers. Tell a school district IT person that you’d like to install a Root Kit at the local elementary school, and you’d better be prepared to run.

We still like the name. Much like the term “hacker,” we want to turn the meaning of “rootkit” on its head and have a little fun with the terminology. So who wants a Root Kit?

19 Jun

Snakes on a Playground

Snake_Sensor_partsThis summer, the playground at Nebinger Elementary School in Bella Vista will lose some impermeable asphalt and gain a rain garden and some porous play surface. It’s all part of a plan to capture stormwater and protect our rivers and streams. But after construction is finished and the vegetation is planted, students may not even realize the function of the system in place.

Thanks to an engaged principal, faculty and educators from the Fairmount Water Works Interpretive Center, however, students are already learning about water-related issues and getting ready for a greener play area (the school already has a very productive vegetable garden in raised planter beds). When teacher Rachel Odoroff was looking for a year-end project for her 7th and 8th grade science classes, we saw an opportunity to introduce some of our work with sensors into the classroom.

The challenge: In two days, work with the students to design and install some sensors to monitor the vegetable garden.

The plan: Well, it’s a bit too ambitious to try to access the school’s WiFi network and get the Solar Sunflower server to display the data, so we decided to make a datalogger to record soil moisture and temperature in the garden. We gave the students a short introduction to the electronics, and they got started with designing the housing. The result? A snake made out of a tupperware container for the head, and pieces of flexible plastic plumbing connectors (the kind you might use to connect pipes under your sink).

Below is the “head” of the snake: an Arduino, an SD card shield (data is written to an SD card, like the memory card in your phone or camera), a battery pack with 4 AAs, and red LED “eyes” that light up when the soil is too dry. The temperature sensor is a black wire that protrudes from the front of the head, like a tongue.

Snake_Sensor_head_sm

Here is the head of the snake in the garden, placed among some tomato plants:

Snake_Sensor_Installed_sm

The tail of the snake—the soil moisture sensor‘s wire threads through the tubing and the sensor is buried about four inches in the ground:

Snake_Sensor_tail_sm

Unfortunately the end of school means the students won’t have an opportunity to examine much of the data, but we’ll be back during the summer to check on the snake every once in a while. We hope to build on this project next year—add wireless communication, upload data to the web in real time, add a light display—and extend it to monitor the rain garden. Thanks to Ms. Odoroff, her students, Drexel co-op Tommy Thompson, and Fairmount Water Works education and outreach coordinator Ellen Schultz for making this project happen. Thanks to PWD engineer Stephen White for coming up with the phrase “snakes on a playground.”

22 Mar

Stroud Shout-Out

Better late than never, a large amount of inspiration for the Solar Sunflower project came from the Stroud Water Research Center, particularly this web page.

stroud_imageImage: Stroud Water Research Center

The image above from Stroud’s website illustrates just how far open-source consumer electronics have come; for a couple hundred dollars, you can build your own sensor network. This is something that was previously off-limits to most civic and non-profit groups—the commercial alternatives cost thousands of dollars. The freedom (literally) afforded by the low cost of these electronic components is important. Sometimes you only want to monitor for a short period of time. Sometimes you have no idea how a sensor will work until you try it out in the field. Sometimes you’ll need to customize your monitoring setup. Arduino and other similar microcontrollers are modular: Switch out the sensors, change the way you power them, try, fail, and try again.

Also worth shouting out is dontflush.me, another fascinating water-related project using real-time low-cost sensors. Arduino-powered sensors detect when a combined sewer overflow is occurring in New York City and lets viewers of the website know not to flush a toilet during these overflow events. (The logic is that flushing a toilet during an overflow would contribute more sewage to the overflow.)