Blog | greenSTEM Network

16 Oct

Northwest Passage

This month, greenSTEM team member Chris Nies is moving to Seattle to ~~join a grunge band 20 years too late~~ accept a job with Amazon. We’re sad to see Chris leave Philly, as he’s been an integral part of this project from our hackathon beginnings. The good news is that Chris will stay involved with greenSTEM and bring our open-source project to the Pacific Northwest. Chris was such an ambassador for Code for Philly and the local tech scene, he got his own bon voyage interview over at Technically Philly.

Chris, you will be missed here. Yes, we are still going to call our sensor kit a Root Kit despite your protests. We’ll leave you with this classic PowerPoint slide from 2013, which during the actual presentation allowed for a third-level Droste effect (Chris standing in front of Chris standing in front of Chris):

23 Jul

Summer Break

Soil moisture data in action – literally akin to watching paint dry.

If you’ve looked at the schools’ soil moisture data lately (via the tree visualization or the raw data), you may think we’re being very liberal with the term “real time.” As schools have taken their summer breaks, most sensors have been pulled from the ground and taken offline for now. Ideally, we’d leave them in all summer when plants need watering the most; volunteer gardeners or maintenance workers may find the data useful. But we’re still developing—both on the technical side and on the human side of things. The project won’t totally cease for the rest of the summer, however; here’s a partial list of items we’ll be working on to improve and expand the greenSTEM Network in spring 2015:

Streamline the installation procedure at schools by preconfiguring the Raspberry Pi to hook into the school’s wifi network. Plug and play.
Replace the temperature sensor with a barometric pressure sensor. Why? Well, the temperature data wasn’t all that useful—it would get really hot inside the plastic cases when exposed to the sun, or if the case was covered it would read too low of a temperature. Using a pressure sensor, we can do some crude weather predictions. When pressure is low, a storm may be coming, and we can increase the rate at which soil moisture readings are taken.
Find a way to securely anchor the Root Kits in the garden. Did Root Kits and their housings get dug up, tossed around, used as a football? Of course they did! They’re in schoolyards. We want them to be visible and have students check them out. We just don’t want them to get damaged.
DO IT YOURSELF INSTRUCTION MANUAL. Many have asked about this, and I swear we are working on it. We got a lot of good photos this year, and we’ll use them to create step-by-step directions on how to make your own Root Kit.
Go solar. Our three-AA battery packs are extremely efficient, but a solar panel charger is better.
Build smarter. Drexel’s ExCITe Center recently awarded greenSTEM Seed Project funding so we can buy materials for more kits and build them at their state-of-the-art facility. We are beyond excited (no pun intended) to be working with them.

Again, this is only a partial to-do list. We’re looking to expand our network of schools next year and watch that tree grow more branches. In the coming weeks, we’re hoping to complete an installation of the sensors at the Franklin Institute, so check back in August for an update.

Finally, now is probably a good time to extend a big thank you to all who helped make this project a success this spring, especially Kevin Clough, Chris Nies, Darya Drahun, Jay Cruz and Ellen Schultz.

12 Jun

Fourth Installation: SLA Beeber

Students at Science Leadership Academy’s Beeber campus installed Root Kit #4 yesterday, capping off an 8-week minicourse of designing and building the sensor housing, soldering the kit’s circuit board, testing radio signal strength, and troubleshooting along the way. Remember the waterlogged sensors from a few posts ago? We did an immersion test and found out water was leaking into the Pelican case at the base of the cable glands:

We used a combination of Rust-oleum Leak Seal spray (not that effective, smells toxic) and silicone caulk (it works, but it’s messy-looking) to waterproof the case. After connecting to the school’s network and testing signal strength from the flowerbed to the 3rd floor office, students buried the soil sensors:

The students went with the eyeball housing for their site, and designated the rocketship design for a future installation at the Franklin Institute this summer (details to come). We poked a pinhole into the eye’s center to allow the antenna to peek out:

Thank you to all the SLA students, Mr. Sokoloff, Darya Drahun and Sandy Sorlien—mission accomplished!

05 Jun

Third Installation: Greenfield Elementary

The sword in the stone now sits among other stones at Greenfield Elementary School. This stone, however, hides a Root Kit, sending soil moisture data to our growing tree. A slight modification was made to the stone when we drilled a pinhole in the top for the Root Kit’s antenna to poke out. Increasingly, we’re finding out that a line of sight between the two antennas is an important factor in keeping the radio signal alive. (For a refresher on how this set-up works, go here.)

Thanks to Mr. Bentz and his 8th grade class, who buried the sensors; and to Drexel co-op Darya Drahun for technical assistance. We noticed during our visit that Greenfield is installing a green roof directly below the science classroom; this would be a fascinating new home for the sensors next year.

03 Jun

Waterlogged

Mysteriously, the sensors at Nebinger and Cook-Wissahickon elementary schools stopped transmitting data late last week. A trip out to each school’s garden quickly revealed the problem: waterlogged Root Kits, with circuit boards and battery cases floating in water. Weren’t these things supposed to be waterproofed? Not against last week’s heavy rain, apparently. We have a hunch as to where the water is getting in; students at SLA Beeber will conduct an immersion test (i.e., put the case in a bucket of water) to see where the water is leaking in and recommend fixes. But for now, the Root Kits are sidelined and drying out, and we’ll test the circuit boards to see if they still work. Check out the futility of the dessicant pack in the photo below:

28 May

Second Installation: Cook-Wissahickon Elementary

Root Kit #2 is in the ground at Cook-Wissahickon Elementary School. This version is a futuristic, light-up LED dome. Admittedly, it’s not that impressive in daylight, but should be an interesting sight as some fiberoptic lights illuminate whenever the sensors take readings (approximately every 10 minutes). It’s situated in a planter bed and sends data to a receiving unit in Mr. Ramos’ second-floor classroom.

Above, the initial setup of the receiving unit (a Raspberry Pi with a JeeLink). It does take some patience and testing to ensure connectivity with the school’s wifi network and determine the best placement for the Raspberry Pi and JeeLink to capture the incoming radio signal from the sensors outside. In these early days of installing greenSTEM sensors at schools, we are lugging around our own monitor, keyboard and mouse to perform the setup procedure; this is something that needs improvement. We’ve attempted many solutions (from hacking an old Motorola lapdock to mirroring the Raspberry Pi on a laptop), but they often result in a system freeze or don’t allow the Pi to make the new wifi connection. Furthermore, the wifi dongle needs to be on a separate, powered USB hub—in short, the Raspberry Pi’s USB ports don’t like too much plugging/unplugging of components and will cause the unit to reboot. A streamlined setup tutorial is on the horizon, most likely this summer. But for now it’s spring—check out how the sensors are responding to rain at Nebinger and Cook-Wissahickon here.

27 May

First Installation: Nebinger Elementary School

The first greenSTEM installation took place last week at George W. Nebinger Elementary School in Bella Vista. The school not only has a new rain garden; it has a new, high-tech rain garden with sensors that allow students to monitor soil moisture in real time via the web. Students can use the data to schedule waterings, analyze meterological patterns, catalog plant species’ watering needs, and correlate environmental data. The sensor kit (called a Root Kit) is tucked inside a spider, the winning design from last month’s student design competition. Data from Nebinger’s garden can now be viewed live on this web page.

Thanks to Ms. Odoroff, her students, George Li from the Philadelphia School District for the technical assistance, and all the helpers who came out to oversee the installation. If the spider looks a little bit worse for the wear in the photo above, that’s largely due to our waterproofing efforts. We used Rust-Oleum LeakSeal (a spray-on rubber coating), and it left some residue. We also ended up poking a hole through the spider’s back for the Root Kit’s antenna; we got a better signal to the 4th floor classroom with the antenna exposed.

Up next: Cook-Wissahickon Elementary School.

08 May

Seeing Daylight

Week 3 at SLA Beeber: Some nice weather made the thought of soldering circuit boards and decorating sensor housings in the classroom unappealing. We jailbreaked to nearby Indian Creek in Morris Park. The west branch of the creek was recently daylighted—the creek had been buried in a sewer in 1928, and the Philadelphia Water Department and the U.S. Army Corps of Engineers recently completed the process of bringing the creek back aboveground. Approximately 750 feet of new stream bed was constructed, and 1,300 feet of stream channel was reconfigured. In the photo above, you can see how the new stream features riffles and pools that serve as habitat for fish and aquatic invertebrates. A blog post at phillywatersheds.org has more detail.

02 May

Eyeballs and Circuits

Week 2 at Science Leadership Academy’s Beeber campus saw the students begin constructing two aspects of the Root Kit: the circuit board (a JeeNode, which is a low-cost, low-power microcontroller with a radio transceiver) that controls the sensors, and the artistic housing that will cover the Root Kit outside in the garden. One group of students soldered while the other group painted.

We followed JeeLabs’ excellent step-by-step instructions to solder the microcontroller boards. The students are charged with creating their own do-it-yourself manual for creating Root Kits, and their main tips for soldering were 1) Keep track of how long the solder wire is—too long and you don’t have much control, too short and you increase the risk of burning yourself; and 2) Soldering gets easier as you go along. Definitely good advice.

The students also got to work on their two housing designs: an eyeball (above), and a crashed rocketship. The eyeball came together quickly: acrylic paint, some glitter glue, and a plastic bowl. It looks excellent—I hadn’t considered how these designs need to be bold and simple; they should be apparent amid garden vegetation from a third-floor classroom window 100 feet away. The eyeball achieves that. More on the rocketship design next week, as we didn’t have quite the right cutting tools for the plastic fins. Student tip for working with recycled 2-liter soda bottles: Use a base coat of white paint first, then put a color coat (in our case, silver) over top of it. The first coat doesn’t adhere well to the bottle’s plastic.

A word of advice for procuring housing materials: Dollar stores are your friend when you can’t find recycled plastics that fit your design needs. Ideally, we’d use recycled materials 100% of the time, but sometimes exceptions are made. Just make those exceptions as cheaply as possible.

24 Apr

Design Day at SLA

Yeah, that does say “duck butt” on the whiteboard. It’s a long story. At Science Leadership Academy’s Beeber campus, a 9th grade class is becoming a company. Its product is the Root Kit, and over the next 8 weeks the students will be responsible for building the kits, soldering the circuit boards, designing the housing, building the housing, installing the sensors, troubleshooting the kit, and creating a do-it-yourself construction manual for other schools. Is that too much to ask?

Yesterday, the SLA Beeber students did some rapid idea generation (I can’t stand the word “brainstorming”) to come up with concepts for the Root Kit housing. Factors to consider: This will be out in a garden, so it has to stand up to the elements; it doesn’t have to be waterproof, but it can’t be made of cardboard and paper, either. Using recycled materials whenever possible is good. And it can’t be made of metal—the radio signal from the Root Kit doesn’t carry well when the antenna is enclosed in metal.

Look back at the top picture and you can see that, based on the distribution of Post-It notes on the whiteboard (a Post-It indicates a student liked an idea), there was little consensus. None at all, in fact. Not even a hint of it. At the end of the day, we narrowed it down to two designs (an eye and a crashed rocketship) based on … I’m not sure, exactly. Buildability was one factor; the garden gnome was a great idea, for example, but we lack the sculpting skills to make it happen at the moment. Also, SLA Beeber’s mascot is a rocket, so that design seemed apt. It’s buildable, too, perhaps using two recycled 2-liter soda bottles.