Down On The (Digital) Farm

How we used sensors, actuators, code and topsoil for our natural Nerd Night

June 8, 2016
Reading Time
4 minutes

Techies, rejoice! Nerd Night is a semi-regular gathering here at IDEO in London, where the community indulges our geekiest passions, explores the edges of making, and learns about new and emerging technologies.

In past editions we’ve invented weird machines with Sam Labs’ connected blocks, drawn on iPads in 3D with Gravity Sketch, and sketched in electronics using Little Bits.

In this edition, London’s freshest face, interaction designer Tim Bouckley, uses mini indoor lettuce farms as an excuse to teach people about physical/digital making.

Ed White: The idea of growing mechatronic lettuce is… er… quite unusual! Where did the inspiration come from?

Tim Bouckley: There had been some interest in the studio about urban and tech-enabled farming following IDEO’s work with INFARM, a Berlin startup working to bring farming indoors. Growing lettuce seemed like a good project to get people into mechatronics—a fancy term for the overlap between the mechanical and electronic engineering disciplines. Since farming is pretty messy and unpredictable, it really pushes the physical side, and it’s something we can all relate to, so it makes the prospect of learning to wire up a circuit or write some code a little less daunting. Combining electronics with wet soil is a fun challenge in itself!


What hardware, software, and other stuff (seeds, soil etc.) did you use, and why?

We gave each person a growing kit of seeds and a container filled with soil, as well as a tech kit of two sensors and one actuator. So, one person might get the peppery Italian salad mix, an LDR (that senses light levels), a tilt switch (that can sense a change in orientation), and a servo motor (that can rotate precisely through 180 degrees).



In our first session, I encouraged everyone to consider how the different components in the kit might work together, and how different combinations might achieve fresh results.The next week, everyone learned to set-up their tech with Arduino: how to take readings from a sensor, then how to use them to drive an actuator—a motor, light, or display, for example. To make things easy, I prepared some ready-to-go code and circuit diagrams. I stuck to Arduino for this project, since It’s still the most versatile tool out there, and it allowed people the freedom to really build out their own ideas, rather than being constrained by templates or limited platforms.


What were the top three ideas people came up with?

Jack had an idea for a pest-controlled mini garden that uses ultrasonic distance sensors to detect and disable any unwanted guests. The sensors set up a perimeter around the lettuce and if a pest wanders in, the sensors trigger a warning buzzer; if it hangs around, it gets electrocuted. (I think Jack is worried about mice in the studio, but I haven’t seen any.)


Then there was an idea for an animated lettuce avatar that uses a simple LCD display with custom characters to bring it to life and express its health and emotions. For example, if the lettuce is wilting, the avatar’s face would be unhappy; if the plant is fit and healthy, the face would be happy.


We also had a sun tracking system that moves a tin-foil reflector into position to make sure the lettuce gets enough rays. It also comes with some mechanical scissors that will automatically harvest the plants when they’re ready.


What did people actually create, and how did they do it, technically?

Here’s one example: Al is working on a rig that will automatically water his lettuce from a reservoir if the soil becomes too dry. He put a moisture sensor probe in the soil, and ran some tests to determine the right threshold value in the code. If the soil moisture falls below that value, the system will trigger an irrigation function. That function is essentially a servo motor that tips a pitcher to water the lettuce. Al is also a bit of a software wizard, so he’s ready to implement a timer in his system so that it wakes up twice a day to check the sensor and then goes back to sleep, conserving power.


How are the plants doing now?

They’re doing pretty well. Actually, most of them are doing so well they need to be planted into bigger containers.

What’s next?

In the final session, people will build and integrate their tech into a physical working rig. Think foam-core and lots of hot-glue. After that, the lettuce should be ready to harvest. Pretty soon, we’ll be able to see whose interventions were the most successful, and eat the results!

Tim Bouckley is a designer and creative technologist in IDEO’s London studio. Ed White is a senior editor in IDEO London’s studio.