$300 Food Computer - MVP


Hello, #nerdfarmers! I’m extremely excited to announce the completion of our $300 Food Computer project!

For nearly three months a core team in St. Louis, Missouri has been working on developing a Food Computer that is designed to be built on a budget, with limited experience. We understand that many of us can’t afford a Food Computer, or have access to the equipment required to make it. We also believe that without complete documentation and help, the learning curve of developing your own system is too great for most to overcome. This makes it very hard for new members of our community to jump right in and start to participate in our learning. We hope that this project breaks down some of those barriers and allows all of us to spend more time being farmers, and get started growing right away! We recommend you approach the project chronologically.

Check out our 2 minute promo video for a quick summary of how to get started.

  1. Assemble supplies
    Order parts from the Bill of Materials (BOM)
    Verify you have all required tools on second tab of BOM, if you are missing any, order them.

  2. Machine parts into ready to assemble Prepared Parts
    Edit 12/17 - New Version: Prepared Parts Documentation

Be aware there are some inconsistencies between video and written documentation.
When in doubt: Follow the written documentation as it is updated to current BOM.

  1. Build Enclosure.
    Edit 12/17 - Old Version: Watch Enclosure Subassembly Video
    Edit 12/17 - New Version: Enclosure Documentation

  2. Build Top Panel or “Brain” assembly.
    Edit 12/17 - Old Version: Watch “Brain” Subassembly Video
    Edit 12/17 - New Version: Brain Documentation

  3. Build MVP Software Stack on SD card & Raspberry Pi
    Edit 1/18 - New Version: Software Documentation
    Edit 12/17 - New Version: Software Installation Guide on GitHub

  4. Complete Final Assembly
    Edit 12/17 - New Version: Final Assembly Documentation

  5. Germinate seeds in Rockwool, balance your PH, and get growing!
    Edit 12/17 - New Document: Operational Documentation

  6. Get involved on the forums, show us your bulid and ask questions.
    Edit 12/17 - New Document: Frequently Asked Questions
    Edit 2/18 - New Link: MVP Wiki - Additional Help
    Edit 2/18 - New Link: MVP Wiki - Guide to Hacking the Software

A huge thank you to the following for their contributions to this project. Just so everyone is clear, we have received no funding or support from an organization or third party, this is entirely an open source product developed for the community, by the community.

@webbhm for writing all of the software and countless phone calls
@drewthomas89 for building our Alpha and Final prototypes and sourcing the BOM
@ceav2b for filming/editing build videos
@pspeth, @jimbell, Ashley Longreigh for their help with the documentation and taking pictures
@ferguman, @wsnook for technical advice and guidance
@melanieshimano, @iancollmceachern for being early adopter beta testers and helping us work out some of the kinks!

ACTUAL costs of computer from experience
Tomato home Greenhouse
MVP - Product Design
Troubleshooting MVP Build
Cloud platform for openAg
$300 MVP Food Computer Variant - My Build
$300 MVP Food Computer Variant - My Build
Aeroponic System Categorization (flex/vertical/horizontal trays)
Pi GPIO pin-out to TD relay and power switch
Climate Computer - Brain Box
Growing rice, mustard, cotton etc
Complete design of the personal food computer (and possible alternatives of some components)
$300 MVP Food Computer Variant - My Build
Libraries & Food Computers: PLIX Build (Public Library Innovation Exchange at MIT Media Lab)
My experience building the MVP food computer
Proposal: Collect MVP code & docs into one github repo
How to get access to personal Food Computer for Education?
Do PFCs dehumidify air?
Proposal: Collect MVP code & docs into one github repo
Vertical Hydroponics Farm in Our Science Lab
Peter Webb Backround & AMA
MVP - Community Development
Growing Plants in Space - MARSfarm Curriculum
Libraries & Food Computers: PLIX Build (Public Library Innovation Exchange at MIT Media Lab)
MVP Food Computer at Akron-Summit County Public Library
COB LED Lighting
Difficulty with MVP system Test: si7021 failure
Difficulty with MVP system Test: si7021 failure
OpenAg for High Schoolers
Need help starting all this
Can I help you with anything — cloud based data gathering, analysis, product development?
OpenAg for Outreachy and Google Summer of Code (GSoC) projects

Very Impressive Peter!

Quick question tho, are the fans, light and pump connected to different relays?

16 years old kid from Czech Republic is trying to build Food Computer

One fan is set to be always on (circulation fan) just because there really isn’t ever a need to shut it off.

The air pump is also set to be always on, also because there really isn’t a need to actuate.

Relay 1 - Exhaust fan (software acts as a thermostat to drop temp when lights are on)
Relay 2-3 - Empty (I plan to add aeroponics and use these, we left them for hacking!)
Relay 4 - Lights on a set photoperiod based on the Cron scheduler (I believe 18-6 is the default)


and what sensors are you using?


SI7021. We have about 6-7 others though we’ve connected if you’re interested. We will be updating wiki completely soon.

Check out the BOM, only takes a minute!


nice work - we at AstroPlant will be sharing our setup soon as well - which will have a similar price tag but geared towards research (we’ll have one plant in it which will be monitored throughout the entire growth cycle). Some info here: www.esa.int/spaceinimages/Images/2017/07/Cosmic_farming


Very cool! Can you tell me a bit more about your program? The work/collaboration you’re doing sounds fascinating.

I’m curious when you say more geared towards research, what type of research do you mean? I find it’s very difficult to create a fully controlled environment for under $1000 or are you focusing on one particular environmental variable?


hey Peter, soon more as we’re working on documentation and website, but for
now: it’s not going to be a controlled environment. The idea is to
distribute these kits (1000 is the goal) across classrooms, urban farms and
homes and to retrieve lots of data from a variety of environments/contexts

  • this is modeled/ put into plant models by the scientists involved. The
    seeds are going to be selected and supplied by ESA. The project is both
    scientific and educational, so slowly but steadily we’re starting to work
    on a educational experience. I’ll be updating here once we have documented
    our prototype. You can also keep up by sending us an email at
    AstroPlant@esa.int - thanks for your interest!



Fabulous core ideas, build, documentation and videos!! Really very impressive.

Thank you for making this for the world!


@thiemehennis please keep us updated, I’m very interested to hear that you are approaching this from a plant modeling point of view. Do you have a goal crop in mind? Also, when do you expect to have your prototype finished?

Thanks, @iancollmceachern, I’m excited to see your kits! (just the “brain” right?) When do you plan to make them available?

Just transplanted 12 day old seedlings into the MVP. I plan to post updates as things progress as well as try and start publishing out my data, and learnings.

Aerated 3 gallons of water in each reservoir for 2 hours to dechlorinate.
Added General Hydroponics FloraDuo A+B equal parts (about 4 ml) to raise PPM by 200 (started at 214, ended 412).
Balanced PH to 6.0 (started at 7.0, added 2 ml PH Down). Always balance PH after adding nutrients!
I then repeated the same process on the other reservoir (knowing the exact amounts I need makes the second time faster).

I’ll post another update with some data in a few days, and try to keep that up for this first grow (Lighting PPFD, Temp/Humidity Charts, PH/EC, Reservoir Changes, etc.)


Great post @Webb.Peter! Thank you for the great detail, helpful to us here as we learn to be farmers. At Open Agriculture Supply we are also having a blast with our first few crops in the MVP Food Computer and hope to share more details soon.

Thank you for asking - this week we made our “brain” kits available on our website for $260. For now we’re calling them the “Open Agriculture Supply MVP Food Computer Power Strip”. Here is a link to the product page on our website. The kit comes with all the parts needed to squeeze all the brains, controls and even sensors of the MVP food computer into a small form factor similar to a power strip. It is designed to safely work with existing, even used or recycled, AC powered devices (fans, lights, pumps, and more) with the OpenAg platform to build low cost Food Computers. What is better than building Food Computers from recycled old “junk”!? Here are a few pictures of the kit:


They’re coming along quick!

Left Side Starting:
PPM - 448 - (Higher because as the plants consumed water or it evaporated it became more concentrated).
PH - 6.5
Right Side Changes: Added 10 ML General Hydroponics FloraDuo A+B equal parts until PPM was 721. Then checked PH which was at 6.5 still, so I added 1 ML PH down just because I know it’s only going to go up.

Right Side Starting:
PPM 447 - I added maybe 1 ML more of nutrient to this side partway through the week. The plants can definitely take it, and the PH was climbing up to almost 7, so I decided to just add a little bit of nutrient to drop the PH (it worked).
PH - 7
Right Side Changes: Added 6 ML General Hydroponics FloraDuo A+B equal parts until PPM was 582. Then checked PH which was at 7 still, so I added 2 ML PH down.

I want to share this specific chart for a reason. It shows a number of things:

  1. The “thermostat” is useful/a worthwhile addition. If you look at the far left side of the chart, see how there is a spike? That’s when the lights kicked on, the temperature is logged every 20 minutes, those lights definitely warm up the box if the exhaust fan isn’t on!

  2. Once the exhaust fan turned on it did a great job of regulating temperature to within a degree of 31C.

  3. I opened up the door (I was checking PH/working on stuff at TechShop) and with the door open the temp dropped to 22C. This is important because (correct me if I’m wrong @webbhm) but crops can double speed for every 10C temperature increase. Regardless, it works, and in theory the same controller could be used on a greenhouse @rcamille @Jon @os_osit.no

@iancollmceachern, it looks like you are using the Pi Camera, our documentation/software isn’t compatible if I’m not mistaken. Do you plan to post a GItHub/Documentation of your specific build as well? I saw that @webbhm offered to help integrate the PI Camera, did you already get that far (I saw a screenshot so I’m assuming so). I just want to make sure we’re compatible here and no one gets confused.

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

@iancollmceachern, @Webb.Peter
The Pi camera and USB camera, while capable of similar use, are quite different at the level of image capture software. The MVP is using fswebcam, while the Pi camera uses Python code. The Pi camera has more software controls, but the ribbon cable can make it a bit more difficult to locate in the MVP.
The standard MVP 1.0 build does not cover the operation of the Pi camera at this time.


Thank you for the clarification.

Just to make that clear for everyone: if you buy one of the kits above it will not be compatible with our initial V1 software stack as of this point in time.

Hopefully, @iancollmceachern has fixed this and has code that does work on Github or even a preloaded SD.


Thank you @Webb.Peter and @webbhm for the clarification. Some further detail:

Our power strip kit has all four USB ports exposed on the top to allow for the connection of a standard USB webcam and therefore work seamlessly with the current MVP software. My thought in designing our housings to include accommodations for both the Raspberry Pi camera and a USB webcam was to allow for folks to experiment with a wider range of hardware if they choose. With our Pi Camera and window mounted within the power strip housing itself the ribbon cable is not an issue and the Pi Camera is much preferable from an electronics packaging standpoint. However if folks want to locate a camera elsewhere in the enclosure away from the power strip the USB camera option is certainly the way to go. Today we have added an option on our product page to allow folks to have the option to order our kit with a standard USB webcam or the Raspberry Pi camera. We do include a pre-loaded SD card with each of our kits.

To be clear for everyone- the above kit will indeed work seamlessly with the MVP Food Computer Software if you select the “USB Webcam - For Use With Unmodified MVP Software” option when you add the kit to you cart. If you select the other Raspberry Pi Camera option it is still compatible with the current MVP software, you will just have to provide your own USB webcam or use modified software to use the alternate camera.

Thanks again to @webbhm for his generous support in getting our first pilot system operational. @Webb.Peter you are correct, we will be sharing detailed build documentation and code on github as soon as I am able to get it together. I am right in the middle of building a second system and clearly documenting the whole process so that we can share the build instructions and code on github - I hope to have time to push this further along once I finish my client work for the week.

One more thanks to everyone working on the MVP!


Thanks for the clarification, camera options are always good.
I think it is a real help that you provide a pre-loaded SD card of stable software, especially since latest release of Raspbian does not currently play well with CouchDB.


Hi Peter and team–

Thank you all so much for putting this together. I have mostly gotten everything to work except the si7021 temp/humidity sensor (localhost:8000 isn’t loading yet, but one step at a time).

Can I post some additional details to help troubleshoot in this thread, or should I e-mail / start a new build thread to discuss where I’ve screwed up?

Thanks again!


I’m so glad to hear that you’re building an MVP!

Regarding your post, it depends:

If you plan to do more of a build guide/continuous post I’d say go ahead and start your own thread (I’ll definitely keep up and try my best to help you out/pull in others to help).

If you have ideas for improvements or suggestions on how to improve/change the system post those to the MVP - Product Design thread.

If you have problems with the software/documentation or notice errors/inconsistencies (I’m sure there are quite a few), then please post those here. The more detail you can provide us with the better we can assist you.

  1. Are you just building the software, or the entire MVP according to the BOM?
  2. What is your background/experience? Is this your first time working on a project like this?
  3. What problems are you having with the SI7021?


Hello, I started make Food Computer in South Korea.

Your Post is advocate me :slight_smile:

And Awesome cost , only 300 $.

I saw your youtube video. and very helpful to me. Thank you.


Sorry to hear you are having issues. The si7021 tends to be very reliable. Please send details of error messages so we can pin down the issue.

  1. Make sure you have enabled the i2C interface for the Raspberry (Main Menu/Preferences/Raspberry Pi Configuration. On the interfaces tab make sure that I2C is enabled.
  2. Check your wiring, and that you are wired to the correct pins.
    Those tend to be the two most frequent issues.