Skip to content

16. Applications and Implications

This week we worked on solidifying plans for our final project. I have gone back and forth between what kind of mechanics I want in my project after doing the group project and working with stepper motors, but I think I’m going to go back to my original idea, inspired by my daughter and our inability to keep plants alive!

Questions for this week

  • What will it do?
  • Who has done what beforehand?
  • What will you design?
  • What materials and components will be used?
  • Where will they come from?
  • How much will they cost?
  • What parts and systems will be made?
  • What processes will be used?
  • What questions need to be answered?
  • How will it be evaluated?

What will it do, What will I design, What parts will be made, What processes will be used

The quick answers to those questions are as follows. More information is below the bulleted list.

  • The modular planter will provide different amounts of light (red and blue spectrum) based on plant needs.
  • I will design the planters, a base for the planters, the stands and holders for the LEDs, a box for the LCD screen and buttons that allows user interface and all system wire and elctronic containment.
  • The base will be cut out of plywood with a CNC machine, the planters will be 3d printed, the LED mechanism will be a combination of 3d printed and acrylic laser cut pieces, the additional packaging will be a combination of 3d printed and laser cut wood or acrylic, as necessary. The LCD and button box will be 3d printed.
  • I will use CNC, 3d printing, laser cutting and the Roland mill for electronics production. Clearly I will also be soldering and determining other connections/fasteners as necessary.

I will make a modular planter using 3d printing for the planters and CNC with plywood to make a base for the planters. You can find some of the basics of the idea on my final project page.

The basic model will have 4 planters, each with its own lightsource. Part of our challenge with growing plants inside at my house is that we really don’t have windows with wide enough ledges to allow for our plants to get natural light. In my research I have found that indoor plants will thrive best with full spectrum light. A combination of red and blue LEDS will allow for a good combination for herbs, which will be our main plants.

The user will choose for each individual plant (4 modules will be made for the prototype) the amount of light required. The LEDs will be programmed to be on for the corresponding number of hours per day. Then in the 2nd spiral (if time allows), there will also be a sensor for the moisture in the soil. There will be one LED programmed to alert the plant owner to the status of the water in the soil. There will be lights programmed to indicate that the soil is too dry, that the soil is in a good range or that the soil is over saturated.

I am designing all parts in Fusion360. You can see the early designs on the final project page above.

Materials, components, sources and cost

Note: there may be some issues with supply chain, so I will alter plans as necessary. The dollar amounts are in USdollars.

Material/Component How much/many Source Total Cost
Adafruit Neopixels - 144 per meter 1 roll Adafruit or Digikey $59.95
5V 4A power supply 1 Adafruit $14.95
2' x 2' baltic birch plywood 1 Makerstock $47.54
KeeYees Soil Moisture Sensor module (5pack) 1 Amazon $8.99
Adafruit Real Time Clock 1 Adafruit $6.95
Buttons (50 pack) 1 Amazon $8.99
LCD screen 16x2 with backpack 1 Amazon $11.99
Attiny1616 1 from lab  

Questions and evaluation

The 144 neopixels per meter will work with a board with 8MHz or 16MHz. The Attiny1616 runs at 16MHz, so this should work. I still have some work to do on making sure all the different parts will all work together. One big question that remains for me is how many boards will I need. Will I need separate boards and then need to connect them in serial (like with our group project?). I will have 4 different neopixel arrays and also if I am able to use the sensors for soil moisture, four of those. There will be an LCD that is controlled with buttons and then a button that selects light level that will then be sent to the program to determine the number of hours of light per day. In the next week I need to figure all of that out.

From my reading I have found that low light plants (including herbs) need 11-18 watts per square foot of grow space. In looking at the neopixel info I’ve determined that this should be sufficient lighting. However, I still need to think about how many neopixels should be over each plant.

Info from this article says that you want to be able to adjust the light’s height as the plant grows. So I will need to think about if this will be possible in the design of the light arm.

Evaluation: this project will be successful if the 4 sets of lights are able to run independently. The best case scenario is that the user is able to input them through the LCD/button part. Worst case, there will be a program with a screen running on the computer and the whole thing will have to be programmed while attached to the computer and then the Attiny will run the lights once it’s disconnected.

If this all works, then I will incorporate the sensors and have those signal, with one of the neopixels per plant, whether the plant needs water or not. Our latest basil plant died from over-watering. We all watered it without telling anyone else it was watered!! I would like to prevent that from happening.

Moisture Sensor

There’s a nice tutorial here on how to use the moisture sensor.

Real Time Clock

Overview to use the real time clock can be found here.

Useful Websites and who has done what before

There are a number of “smart” planters in existence.

Some previous fab projects that involve plants with sensors and other ideas that are useful as I design my project:

Some important research on what plants need for light and grow lights * How much light do different herbs need * info on best grow lamps * you tube video on grow lights * Growing basil indoors * pH for plants * Growing basil inside: focus on light intensity and spectrum lots of other useful info here about basil inside * article in Washington Post about LEDs in indoor farming * use NeoPixel Ring for indoor lighting for plants * helpful article about LEDs for growing * an article on lighting for herbs. It recommends LEDs and has link to some products

Some additional options for future iterations * Planters with solar uplighting

Other possible materials

South Boston, acrylic company (ask Jason) RISD store for baltic birch (ask Kelley)

Last update: June 1, 2022