Current Version of the MVP - Go here for complete documentation = $300 Food Computer
Now we must define the goals and requirements of the physical (and virtual) MVP that the community develops. I believe that of the user groups I listed in my previous post, MVP – Community, the two that will have the largest impact on this project in the near future are makers and teachers. It is for this reason that I propose we develop our MVP to be designed by the average hobbyist maker, and is intended to be operated by an elementary school teacher with the help of their class. It is important that we distinguish what user is the builder and what user is the operator, as these impact our design decisions. For example: a maker may not be worried about their system running without human intervention for a week at a time, but a teacher needs this automation to keep the plants alive during vacation or Spring break.
We have defined who will be the user of this product, which leads us to our second objective: determining our target recipe. It will drastically change our requirements if we are growing leafy greens, as opposed to a tomato. I know that everyone is probably getting sick of lettuce, but I do think that it will have the least system requirements and max potential learnings due to availability of data. @webbhm has already started the data model based upon the Cornell guide, which provides great setpoints for each of our variables:
I am making an attempt to define the requirements myself because I am hoping to inspire critical feedback as opposed to just passive awareness. My goal here is not to say that I know the best way to do something, but instead create a process by which all of us can work together to find the best (per our agreed definition) solution.
- Product goals for PFC
- STEAM platform for teaching about ecosystems and life sciences
- Grow food based upon a standardized OpenAg recipe
- Hackable, and modular system maximize hardware variation & scalability
- Control as many variables as possible to maximize value of data
- Product goals for MVP
- Online remote sensor and webcam monitoring via mobile device
- Be constructed with a “home-owner” level of skills and tools
- Price - Cost less than $300, with parts from minimal suppliers
- Product requirements of MVP
- Brain - Should we reuse the PFC V2 Brain? Brain_box? Or something else…
- Camera - Can we get by with just one? @Eddie Are two camera’s going to be necessary to take advantage of computer vision phenotyping software?
- Enclosure - Aluminum? Simple wood frame? Foam Farm Box?
- Lighting - No lux sensor, standardized distance and spectral output based on bulb
- Reservoir - Determines footprint of the enclosure. Bus tub? Smaller? Just 1 plant?
- Oxygen - None? (Kratky), Air pump from PFC V2?, or $5 Aquarium pump
- EC - Manual control - Standardize by using same nutrients & weekly reservoir changes.
- PH - Manual control - Anyone know of cheaper kits than this?
- Water top off? - Sensor, peristaltic pump. While this isn’t absolutely necessary, I think it allows for this plant to be left unattended for much longer.
- Temperature - Sensor, have people experienced that the heater is necessary? Maybe the heat from the lights is enough? Then an exhaust PC fan can cool when needed. Perhaps someone has an idea for evaporative cooling?
- Humidity - Sensor, humidifier - piezo? Any other creative ideas for raising humidity cheaply?
- Co2 - Does anyone know a good way to pull this data for cities? I’m thinking maybe we could
- Software - Initially when PFC V2 stack, off the shelf IoT solution
- Blynk - @campergeek @MrGadget have used this before with success. I also found there to be a dozen other plant growth chambers built using Blynk in their community.
- Scratch? In the Media Lab they have a looping video of this being a UI for recipe building. @24Karrots is a fan of the simplicity and appeal to children. I also know it was created at the Media Lab.
Here are some existing examples, I will continue to add more as we find them.