MVP - Community Development


Update: Check out our Alpha BOM/Software stack on this thread.

This is the first of three posts I will be making related to the development of a Personal Food Computer (PFC) Minimum Viable Product (MVP). An MVP as defined by Eric Reis in his book The Lean Startup “That version of the product that enables a full turn of the Build-Measure-Learn loop with a minimum amount of effort and the least amount of development time.”

I think many of us are eager to start building, but it is equally important that we make sure we have ways to measure and learn from our builds. The whole point of these posts is to try to promote discussion and create consensus on requirements & goals as we move forward with the development of an MVP PFC as a community.

If you want to build alongside, help with any part of this project (PLEASE) just let me know what specific area of interest you have. Perhaps you would like to create the lighting sub-assembly, or write the code for the “thermostat” even if you aren’t sure, let me know a bit about what interests you most in OpenAg. If you have additional concerns or think I am missing something, please leave a comment. I am making these posts purely out of the hope that it will unite us behind common goals and requirements. If you are looking for a space where your voice can be heard, or your needs can be met, you are exactly who needs to speak up. I hope my attempt at organising this effort will be well received, this began with conversations in the community and @caleb has expressed his desire for us to develop the MVP.

  • Community Goals for PFC
    • DIY project that appeals to early adopters who have right skills (makers)
    • Interactive educational tool to teach about ecosystems & life science (teachers)
    • Research platform to crowdsource experimental plant science research (scientists)
    • Grow food based on recipes with automated systems anywhere (farmers)
    • Customizable, safe, sustainable food supply independent of climate (foodies)
  • Community requirements for MVP
    • Collaborative decision-making methods and voting to make sure MVP serves community
    • Short cycle time of a few months with defined target user, and recipe use case
    • Maintain alignment by sharing as much information as quickly as possible
    • Create complete open source documentation in the MVP_PFC wiki (Thank’s, for starting this, it is appreciated)

Here are my next steps:
Week 1 - Survey’s on the 3 threads based upon outstanding questions and to vote on goals & requirements.
Week 2 - Deliver MVP goals/requirements documentation based on community feedback.
Week 3 - Release alpha version of documentation (Ordering BOM, CAD, Software architecture).
Week 4 - Determine design & assign sub-assembly & software development projects.
Week 5 - Release beta version of documentation (GitHub Repo, CNC, Software Walkthrough).
Week 6 - Document build instructions and share feedback and determine required improvements.
Week 7 - Debug and release final version containing all documentation above and build guide.
Week 8 - Evaluate process to determine validated learning and justify “ROI” of MVP, this feedback begins next cycle.

Post 1 - MVP - Community Development
Post 2 - MVP - Product Design
Post 3 - MVP - Future of Process

MVP - Future of Process
MVP - Product Design
MVP - Product Design
$300 Food Computer

@Webb.Peter I sent you a DM with my contact info. Maybe we can talk and compare notes some time soon.


Thanks @Webb.Peter Its really evident how much work and thought went into these posts, and its exciting to see where they can go.

There is a lot to unpack here, but ill start with your goals of going into schools to work with teachers and students.

I am really excited about this approach to the process. I recently was part of a small team of urban farmers that went in to teach a class on hydroponics to middle school students, and saw the way they responded with amazement and wonder. Engaging kids and schools is the exact way that this community can grow and make an impact to the world. Also, its amazing how many hundreds-of-BILLIONS of dollars a year that of purchases that kids influence their parents to make, so kids are a very real way to influence policy and economies.

Agtech is amazing because it is able to connect so many people to a common goal through the lens of their lives and their unique interests. Whether you are into art, biology, business or engineering there is an opportunity to have an impact through the lens of urban agriculture. If we can connect youth to the wonders of this space, there is an opportunity for a very green future.

Lastly, If you haven’t heard of the Green Bronx Machine and Stephen Ritz, you must watch his amazing TED talk:


@TechBrainstorm it goes without question that when kids are involved in growing food they are much more likely to want to eat it, and you’re absolutely right that those bad habits get taken home. I am working with a group here in STL called The Green House Venture who has the mission: “To create a nationally visible demonstration facility for year-round, sustainable, urban agriculture that instills an appreciation of the cycles and processes of nature and health, that broadens the education experience of elementary school students in the Urban Education Alliance District, that optimizes technology to remotely share its program with other interested elementary schools throughout the region, and that offers nutritious fresh produce to the community’s needy.” To me, this is exactly the kind of facility that can provide an introduction to plant science in a hands-on exploratory learning setting.

I am actually reading Stephen Ritz’s book right now, he is an incredible educator and a great example of just how far just a little bit of technology in the right hands can go a very long way. If I’m not mistaken he’s coming out with a curriculum, correct? Do you know anything about that?

Do you think the MVP as it has been outlined would be a viable teaching tool for an elementary/middle school? I know Green Bronx machine uses Tower Gardens which is essentially just hydroponics and doesn’t have any level of automation. Do you think that educators would benefit from a “grow box” as opposed to just learning about hydroponics via a Tower Garden or simple YouTube hydroponic system? I think the question I’m trying to ask is whether or not you think there is a direct value in teaching about controlled environment agriculture, as opposed to just learning about plants and urban agriculture in general. If you do, how do you think we should “Get the word out” to all of the schools out there building there own solutions from scratch or buying overpriced products.

Appreciate the feedback, I hope to hear more, it sounds like we’re definitely in agreement!



I’ve already made the decision that our MVP PFC will be be built without the use of CNC equipment, using primarily locally sourced materials. The food part will be lettuce grown in a closed container, using a hydroponic (DWC) system and store bought LEDs that do not require a driver. The computer part, I beleive requires a camera to provide meaningful datasets, as well as some form of sensing and acutation. If you’d like to know more about why I made these decisions please visit Post 2 - MVP - Product Design. I really appreciate everyone’s feedback so far and am excited to continue to develop this together.

What should be the goal cost of our MVP?

  • 50
  • 100
  • 150
  • 200
  • 250
  • 300
  • 350
  • 400
  • 450
  • 500

0 voters

What size should the MVP be?

  • Minimum Size for One Plant
  • Same as PFC V2

0 voters

Minimum sensing requirements?

  • Temperature (Air)
  • Temperature (Water)
  • Humidity (Air)
  • Water Level (Float)

0 voters

Minimum actuation requirements?

  • On/Off Relay (Blinking LEDs, 120V relay)
  • Variable Actuation (Looping, Thermostat)

0 voters

Should we utilize the OpenAg hardware (Yes) or explore alternatives (No) for the brain & sensors?

  • Yes
  • No

0 voters

MVP - Product Design

@Webb.Peter My answer to all of your survey questions is, “it depends on your goals”.

It seems like there are at least three distinct user stories that people have implicitly been discussing as the basis for an MVP design:

  1. Classroom food computer: Lives in a school classroom. Maintained by teacher and students. Needs to grow enough plants to be interesting for the kids. Needs to be self sufficient for week long vacations. Probably gets paid for with grant money or maybe from bond issue funds. Depending on the funding source, there might be seemingly arbitrary approval processes triggered by maximum or minimum price ranges–teachers would know more about this. The main goals are related to STEM/STEAM curriculum, aligning with the objectives of grant funders, and inspiring kids to eat well and take an interest in farming.

  2. Modest budget Maker project in the US (reliable power, low network latency, easy to source parts): I’m in this category. Reliability and simplicity are key priorities. I’m primarily focused on creating building blocks that can be composed into larger systems. I also care about writing guides and documentation. My purchasing decisions are aimed at quality, reliability, and ease of use–I want people to be able to reproduce my results. My main goals are to enjoy the process of quality craftsmanship and to help people–me included–prepare for careers in indoor farming.

  3. Low budget Maker project, maybe outside the US: It needs to be cheap. Sourcing parts may be a problem. Network connectivity and latency may be a problem. Power may be unreliable. The goals might be to have a project for learning about growing plants, to start a business, to grow crops for eating, etc. Requiring more manual tasks to keep the cost down is fine. Providing automated assistance with ensuring a repeatable procedure is followed and with keeping regular, accurate records are still important though.

I left “high budget Maker project” off the list because the PFC2 already has that covered.


For the sake of clarity, everything I am talking about refers to MVP’s as it stands to what I expect to accomplish in my two month timeline. That being said, any of these 3 options could be improved upon and one day manufactured as a “kit” like the PFC V2 is. My goal is to create opportunities for entreprenuers as well as simple platforms on which other people can build.

  1. In order for the single user to be a teacher, I believe to operate the MVP they would need to be considered a “maker” as well. Even the Fenome kits aren’t to a point where the average teacher could assemble one. I think in the case of our MVP it is unlikely that our software will be simple enough as well for someone who isn’t really committed and personally interested in the project. I agree with you that in some cases a PFC would be funded via grant, or the school that is not what I think would happen with most MVP PFC’s. In the situations I know of where someone would want to utilise a MVP PFC for education, they are all not official educators. They are parents, or members of nonprofits that work with schools, not “teachers” as you would think in the classroom. Early on I made the distinction that I think there are two possible users of PFC MVP’s, the builder, and the operator. In my head if this MVP PFC were to be placed in a classroom it would be through a personal connection/donation to a specific school. We aren’t trying to get a school district to incorporate it as a part of the science curriculum, that doesn’t mean that an innovative teacher couldn’t find $300 in their budget ($3500+ is a different story). I also have the motivation to eliminate waste, it would pain me to see people build an MVP, grow two crops and then set it aside because they scale up their project. To me, if we plan ahead for the “operator” to be a different person from the builder, we massively expand the opportunities for MVP applications. I also think that by including educators in the operation it will help us develop the curriculum (training guides) that I believe should go alongside our “recipes”.

  2. This is extremely good to know, thank you for defining this category, I’m curious as to who else falls in this zone. How much do CAD & CNC drawings matter to you? How long would you forsee an MVP’s lifespan to be before you’d want to “scale up”. At which point, do you see value in controlling many more variables while the container is so small, or your next step would be to develop a larger system, my point is perhaps it may never be worth it to put Co2 actuation in a PFC. PFC’s will always be a sort of stepping stone for “makers”, I’m curious as to which direction you may want to go in next to determine if there is ever value in making the MVP PFC scalable to do much beyond what we’ve discussed. Perhaps this may be more appropriate for the “Future of the Process” thread if you have a long answer (I’m genuinely interested).

  3. I think this will always be a difficult category. That being said I think there are extremely valuable contributions that this user group can make. To me (where I live in the U.S.) this almost falls into more of the “sustainable” or “urban farm” category who is trying to take small steps into learning how technology integrates. I think the way that we can help this category in the immediate with the MVP is to allow for the software, and the system itself to be somewhat independent. Or, at least make it very “hackable” so that the “MVP Brain” can be used top of any sort of setup, regardless of whether it’s a water bottle or a greenhouse.

Here are my current thoughts that I hope make this modular enough to make all 3 groups happy (still very much so in development but I’m trying to be transparent):

We should develop an “MVP Brain Box” that can be mounted onto an MVP PFC. The brain will do camera logging, and basic environmental sensing, as well as run our MVP software stack, which will connect to an OpenAg recipe. For those who want to hack it to plug into a larger greenhouse fan, or mount it on any other box they’d prefer are welcome to do so and will make sure we plan accordingly to enable such mods.


I use the term MVP because some of the people here use it, but that’s not how I think of what I’m doing. Invoking the language of Silicon Valley startups implies a lot of stuff. Where are the VCs? How long is our runway? Are we burning fast enough? Who are the founders? What’s their exit strategy? How does that metaphor fit what we’re doing here?

For the last few months, I’ve been fortunate to have free time to devote to learning a new set of skills at the intersection of several of my long term interests: food, writing, teaching, writing code, photography, etc. My intention is to eventually go work somewhere with a budget and team to do much more than what I can accomplish on my own. To me, the usefulness of what we’re doing is to learn about botany, hydroponics, and programming in a way that helps other people learn along with us. The end goal is to help a new generation of farmers deal with challenges on Earth and elsewhere. Who’s gonna grow all the food up on Elon Musk’s Mars colony? How will they learn to do that?


Peter - Thanks for introducing this topic to the forum. My work at OpenAg is focused on how we can use PFCs as a tool in an educational capacity. There are a number of amazing, innovative teachers and students on the forum that can probably offer some expert guidance. @MrsHesseltine, @tracyp, @essextech, @saputom, @melanieshimano, @Dr_Kelly, @ceav2b, @SelinaWayne, @julianak, @eblouin, and any other teachers/students I missed - would love to get your feedback on some of the questions raised in this thread.

  • What kind of technical ability do you need to complete a build?

  • Is cost a deciding factor in whether or not you would utilize this tool in school? If so, would you seek out additional funding opportunities to have a PFC in your school?

  • Would you prefer the bots came with a curriculum or would you like to incorporate the technology into your own lesson plans?

  • What types of sensors/actuators are most important to you?

  • Are the students more interested in a bot that is entirely automated (plug in a climate recipe and watch the plants grow) or do they prefer to have a more hands on experience (for example manually dosing nutrients)?

Any insight you can provide would be greatly appreciated!


I really appreciate you pointing the educators in this direction. They are our defined user, and I am working with a few people locally with hands-on classroom experience but getting insight from others especially actual PFC users would be extremely helpful.

Here is a short summary of where we stand with the MVP:

User: Average hobbyist maker, and is intended to be operated by an elementary school teacher with the help of their class.
Goal: Grow a leafy green (burpee buttercrunch lettuce will be the first recipe we make modeled after Cornell’s guide).

Minimum Requirements based upon discussion here:

  • Brain:
  • Use only the Raspbrry Pi, no arduino. It is inexpensive and has a full Linux software stack.
  • Camera:
  • Only one camera is sufficient to monitor growth and do a timelapse. Placed at the top works the best.
  • Enclosure:
  • PVC Piping (or any other basic framing material) to create an enclosure same size as PFC V2. I will plan to mount electronics on top.
  • A circulation fan will be reqiured to make sure the seedlings are
  • Lighting:
  • Off the shelf LED bulbs and regular hardware fixtures
  • 4 Soft White 3500K GE Bright Stik LED’s. This gives us at the top of the bus tub (same dimensions as PFC V2) 195 umol/m2/s2 and will cost less than $30.
  • Reservoir:
  • We think standardizing the size is more important than specific material, we will suggest bus tub, but explain that another type of tub with XYZ requirements and XYZ dimensions will work just as well.
  • Oxygen:
  • $5 Aquarium pump.
  • EC:
  • Manual control.
  • PH:
  • Manual control.
  • Water top off:
  • As suggested: two sensors, peristaltic pump. Allows unattended operation for days, this could be an “add-on” like the camera, where the very basic MVP doesn’t need it, but for our end goal user we think it is a nice to have for things like spring break.
  • Environment:
  • Temperature & Humidity logging/real time monitoring.
  • Thermostat
    • Just a PC fan to exhaust the heat from the basic grow light set to turn on/off when target temperature is exceeded.
  • Co2:
  • Ignore.
  • Software - Still working on this part…I’m extremely curious to hear from teachers their experience “turning on” the PFC and difficulties navigating through firewalls and getting the software running. I myself am building a V2 kit and haven’t yet been able to get the software functional.
  • PFC V2 stack: complex, but already (mostly) done and can be hacked to be simpler for the MVP.
    • Pros: will read existing recipes and write the same format data.
    • Cons: complex SW stack.
  • @webbhm is writing another very simple and basic MVP software stack we hope to release by Thursday.


Looking forward to build this MVP, Also i would like to be part of the software related discussion and contribute.


@webbhm will be posting our initial software stack to the MVP - Alpha Release thread today.


Please take a look at the code. It is all on Github.
The has documentation, including some thoughts on future development.

To get going, you can easily substitute several LEDs for the relay (or plug them into the relay) and get the software up and running, and see results.


A quick suggestion would be to put *.pyc into .gitignore. I won’t be able to test the code till this week but as soon as i get my parts i will be working on this and might send some PR’s


My MVP setup. Used the same hardware spec as in the docs except the grow chamber and fans. Rewrote and organized code a bit. Works as charm. Next step is to automate pumps and fans, build a grow chamber, waiting for aeroponics design to be released.


What changes did you make to the code? We may want to make a fork in the Github and add your changes.


I structured the code in below way. Tried to work on implementing a few features. Added couchdb to store data and working on building a UI to display that.

Its WIP, i will share the repo once i get done in next 1-2 days.


@nav, @d
I think I may like your structure better than what I am doing, though we may have to work through some semantics (and I may need to clean up some code structure). It also looks like you have a better background in UNIX and python than I have (I still don’t understnad the and .gitignore).
My impression is that you are ignoring file type (.py, .sh) and organizing by function. In this case, the python code that gets data (sensors like go in “modules”, python code that changes or actuates something ( goes in 'tasks"; both of these should be functions. Those that do something, and are likely called from the crontab ( would be a task. Is this your direction?


I haven’t written python code in 3 years, so quite rusty with the concepts. You might find a lot of non pythonic code in the codebase and a few hacks here and there.

.pyc is the compiled bytecode of respective .py file. If you import a module, python will build a *.pyc file that contains the bytecode to make importing it again later easier (and faster). It should not be committed into codebase.
.gitignore is related to git, it does not add files/folders etc to git when specified.

My thought behind the folder structure -

Modules -
The modules have functionality specific code, idea is to keep logical separation between different entities. I feel there is more scope of abstraction and reducing lines of code but it’s an MVP so i will do that in later versions.

Tasks -
Tasks are basically tasks that have to be performed by the application, They contain the logic of invoking a tasks, for ex parse a config file and and decide which function(s) to call to perform any given tasks.

Rest of it is pretty much thought on the fly, is poorly designed and i feel the need to work on something more simplified than cluster mess of if/elif/else.

TLDR: It’s a tradeoff between shipping early and shipping perfect. I tried to have a balance.

Here is github repo -


Hello, #nerdfarmers,

Update for those of you out there who are interested/care about the MVP project:

  • We will be recording a build video/revising BOM/build instructions over the course of this weekend/next few weeks. I don’t want to promise a date, but really hope to make a post within two weeks with the final release of the MVP PFC V1.
  • Initially we planned for this to be a 2 month process, which I think was a good timeline to develop a beta prototype. I really like that we stuck with that and forced ourselves to release what felt like incomplete documentation/work. Going forward I would strongly encourage anyone else who wants to develop a product to take advantage of this community, truly, everyones feedback/testing has made the end result signifiantly better. If you don’t beleive me just go to part 2 of this series of threads and read through the product development process & open conversation.
  • I have been encouraging others to start developing other branches of the MVP going forward. My vision for this is discussed more in the future of the process post. I would love to see an MVP Food Server, High Pressure Aeroponic reservoir, greenhouse controller, aquaponic monitoring/alarm system, bugbot (yep, bugs to eat), to name a few. Clearly I can’t do this alone, which is why I look forward to seeing others lead these projects in the future.

Thanks to everyone who has thusfar participated.