Libraries & Food Computers: PLIX Build (Public Library Innovation Exchange at MIT Media Lab)


Shout-out to @mmcneal for the great work being done in Akron, I found this video via MIT Media Lab Twitter:


So, we hit a hurdle that killed our momentum, but we are moving again.

I’ll explain the obstacle, and then I’ll talk about what is happening now.

With the raspberry pi, you need a monitor, keyboard, and mouse. We didn’t have any extras of those things at McPherson Square. But we had a group of kids working each day on the food computer. So, I borrowed the equipment for the office upstairs. However, all of our equipment at McPherson is a bit dated. None of our monitors, for example, have an HDMI port. In the end, we were unable to work with the raspberry pi with any of the equipment at McPherson Square Library.

We asked our LEAP program for help. They ordered raspberry pi mini-monitors. This delay hurt our momentum, but we still had an active group waiting for the supplies to arrive. However, upon their arrival, we discovered that the text was too small for anyone to use. This additional hurdle took us to the end of the school year, and we lost most of the kids active in the project.

One thing to keep in mind working with public institutions is that scarcity of resources can be real issue. Even something as simple as an extra keyboard presents us with a challenge. Moreover, running a drop-in program with teenagers requires maintaining momentum. If we get fortunate enough to have teenagers choosing to come to library on a project, we want to keep that motivating factor in play.

With the project temporarily stalled, I detached the raspberry pi and set out to find a functional system. Working with Leah at Lillian Marrero. we have managed to get a compatible monitor, two keyboards and two mice. Further, we were able to upload and install NOOBS onto both raspberry pis.

At McPherson Square, we have had a few teenagers coming to program this summer that self-describe themselves as interested in technology. I have taken this as an opportunity to pitch the food computer. On Thursday, we had four teenagers work together, successfully boot the pi and connect it to the internet. I had them attempt to test the sensor, but they were working with the mini-monitor and found that too difficult.

The plan for next week is to clean and redo germination process. Hopefully, I will be able to find a work around for our monitor challenge, and we will have a functional food computer in the next couple of weeks. As we make progress, I will update the forum.


There may be another solution for you that I am using. I have multiple Raspberry Pis running, but only one keyboard and monitor. If you do not have a monitor and keyboard, you can download the software on any Windows PC or laptop and use it to access the Raspberries. It takes a bit of work, but not much.
Built into the Raspberry software is a program called VNC, it allows you to access and display another Raspberry on your network (found under Menu/Internet/VNC Viewer). To use it you first need to enable it via Menu/Preferences/Raspberry Pi COnfiguration; go to the Interfaces tab and Enable VNC.
From the VNC Viewer program go to File/New Connection and enter the IP address (network id) of the other Raspberry, and give it a useful name. Then when you click that name on the screen, it will bring you up a window showing the other computer. From this, you can do anything you could do if you directly accessed the other Raspberry. VNC gives you the full windows environment, which can be easier than using something like Putty and SSH that only gives you a command line.

Get your support people through LEAP and MIT to help you with this, as it is easier to do than to explain in a forum post.


Hey Bryan - Sorry to hear about these issues with the core equipment. And glad you were able to keep going. Thanks for sharing!

This kind of feedback is super useful especially as we prepare for a roll-out to other libraries. I think we might need to think about a basic “kit” of materials and equipment beyond the core food computer that libraries need to have access to (either they have spare equipment or it has to come as part of the project).

If you run into roadblocks like this where a little bit of help (a spare keyboard) could make a huge difference please also feel free to reach out to anyone in the PLIX team by email. Since this is the prototyping phase of the library deployments we will do what we can to help! We definitely don’t want you to get stuck.


I am very sorry to hear that this roadblock caused you to lose kids who had been interested.

@ps1 Feel free to E-mail me personally as well if there is anything I can do to support: it is extremely important to me that Food Computers are a positive experience for educators who take the risk implementing them with students.

  1. @pspeth has found a 7" touch-screen monitor for less than $50 which he’s been using successfully. I will follow-up with him to get you that link.
  2. In addition, I want to second @webbhm’s comments regarding VNC/SSH access. It can seem foreign if you aren’t familiar with networks/programming, but I assure you once you’ve done this once it will really simplify things in the future:
  3. We are working to develop a more robust UI for the Food Computers. Part of this experience will include the ability to use any device with Wi-Fi and a browser to locally connect. If any developers out there would like to help us develop this feature please fork our UI repo on the FutureAg STL GitHub. My goal is something similar to the functionality of Farmbots configurator which doesn’t require mouse/keyboard/monitor:


Thanks everyone for the feedback. We are having a very positive experience overall. Part of our student driven approach is the acceptance that roadblocks happen.

Our present work around is to use a projector in place of a monitor. This has the advantage of being viewable by a group. On Monday, a teen worked a bit on the pi. However, it was a busy day and I am doing programming on my own. So, I wasn’t able to set him up to try making remote access work. Remote access will be the next thing we will try.


I’ve had good luck picking up used monitors very cheaply at second hand stores such as good will. You may need an HDMI to VGA convertor because the old monitors tend to be VGA and the RP is HDMI. You can get the convertor’s on Amazon.


Also, you can use an IOT cloud service like Cayenne ( in order to connect to and manage your Raspberry. They support VNC and automatic sensor detection on the Raspberry Pi. Their website has a wealth of documentation on how to get started.


Our teens worked on establishing VNC/SSH access. However, we are working with the library’s wifi, and the teens believed that the library’s wifi was blocking such access.

Our staff met with Jehan Luth on Friday to discuss troubleshooting. He agreed with my teen’s diagnosis of the issue. I have an old wireless router that we are going to try as a workaround.

Our teen assistants have this week off, and then the program is cancelled the following week for training. In two weeks, we will begin the back-to-school/fall schedule. My hope is that we can have viable solutions for the kids to try, when they come back.


We are dealing with two hurdles, right now. One, the library wifi blocks the networking necessary to run our pi. We have managed to get an old router and could use it as a work around, but will need instructions on how to do so. Two, our pi doesn’t recognize any of our sensors.

  1. I am not sure I know what you mean by the wifi is blocking networking. Can you do an internet search? If you can reach the internet, that should be all you need.
    Could you temporarly take the Raspberry Pi (or a second one) home or somewhere with wifi and download the software. You only need wifi while downloading the code.
    If you are trying to VNC between the Pis, then simply setting up the router as a wifi hot-spot should work, with the Raspberries connected to that wifi. I would need more details on the router to help further.
  2. If the python code is running, then I would check out the wiring (especially the pin positions). Start with the relay and do some low level tests to see that it is getting the signals (you will see the leds turn on and off). For the temperature (SI7021) there are some low level tests I could walk you through to check out your I2C bus.


I think he is thinking the library’s network firewall is blocking SSH, VNC, etc. Protocols. I would assume that may be the case. VNC is more likely to be open than SSH. Hard to know unless you can ask the library IT people.


Hi there,
Just wanted to let you know about the results of our most recent FC experiment:
We grew the same lettuce variety in the FC and in a garden over the same time frame and invited our staff and customers to do a blind taste test. Unfortunately there was a definite preference for the garden grown lettuce, but there were also a good number of tasters who felt there was no difference.




Did you get any feedback as to why they preferred the garden lettuce? Was it taste, texture of something else?
That is a great experiment, and the sort of information that is good to collect.


The general comment was that the hydroponically grown lettuce had a slightly more bitter flavor compared to that grown in the garden.


@mmcneal This can be due to a number of things related to pH, nutrients, as well as the age of the plant.

I can personally say I’ve grown a lot of bitter lettuce. That being said when my plants aren’t looking very good, I ALWAYS have bitter lettuce. I’ve also had some of the sweetest lettuce of my life which was grown hydroponically.

There’s quite a few topics on this subject, here’s a good starting point if you’re curious in digging deeper into the “Why” behind your findings: Growing Veggies packed w/ Flavor & Nutrition


Hello I’m Brayant i’m 13 I live in philly some of you might of remember me for the library I’m the kid who help with the food computer.

We have did the all the step for the 300 hundred dollar food computer. We did the germination step and we had some stuff growing.

We need instructions for the next step. thank you


Hey Brayant! Great to hear! We met while OpenAg was there and chatted a little bit about your favorite parts of growing.

The next step is to make sure your Food Computer is ready to grow. If everything’s working right, then it’s time to see if your seedlings are ready. If you ask Mr Belknap (@belknapb) about the Growing Guide from the PLIX project, there’s some good things to check in there before you put your seedlings into the Food Computer.

Mostly, you’re looking for “true leaves” on your plants. If you’ve got those, you’re ready to move over your baby plants and let them grow in the Food Computer.

Maybe @mmcneal and the Akron Library folks can tell you what they did to transplant, or Ms. Shimano (@melanieshimano) has some tips for what’s next.

Can’t wait to hear how it goes!
-hildreth & team from openag


Hi Brayant! Congratulations!

As Hildreth suggested, you will want to test out the Food Computer before putting your seedings in (you want to be sure the temperature and humidity is remaining at a nice constant level and that the lights are turning on and off as expected.)

Once that’s done, the transplanting was pretty straightforward. Simply position your growing media (rockwool) in the basket and fill in around the edges with the aquarium gravel. Some of the small pieces will fall through, but just set them aside and use the larger ones.

Once the baskets are filled, you can place them into the prepared lids on the bins and you’re ready to roll.

Keep us posted on your progress!!


Bryan Belknap, here, thanks Hildreth and Michele for the response. Hildreth, you referred us to the Growth Guide. I am not familiar with that. Is there a link? Thanks.