Aqua Floralis: How to Build a Solar Powered Weather Station That Takes Care of Your Plants in a Cool Way

This project was born from the frustration of taking care of plants in extremely hot areas. It always happened to me that, despite my efforts, the plants dried out and I ended up feeling like a bad “dad” to them. There are devices that tell you when a plant needs water, but most of them are not very aesthetic and even boring. So I set out to create a solution that combines technology, art and functionality: a flower that, in addition to beautifying the environment, opens and closes diurnally and acts as a weather station for your plant. The Aqua Floralis not only monitors humidity, temperature and light, but is also powered by solar energy, making it ideal for both indoors and outdoors.

Electronics:

1. x1 Solar panel christmas lights (more info in step 3) - [Amazon link]
2. x1 ESP8266 NodeMCU - [Amazon link]
3. x1 MT3608 Voltage Booster - [Amazon link]
4. x1 MG90S servo (preferably metal) - [Amazon link]
5. x1 Moisture sensor for the ground or an alternative sensor (more info in step 11) - [Amazon link]
6. x1 DHT11 sensor - [Amazon link]
7. x1 Photoresistor - [Amazon link]
8. x1 4.7 kΩ Resistor - [Amazon link]
9. x2 Nails of 7 cm (stainless steel)
10. Dupont cables of different sizes

Case:

1. x8 Elastic bands
2. x1 M3 x 2.5 cm screw
3. x4 Screws M2 x 0.5 cm
4. x1 M3 nut
5. x2 washers M3 x 1 cm
6. 3 meters of fishing line
7. Hot silicone
8. Paint and post-processing materials (more info in step 2)
9. 3D printing filament (more info in step 2)

I designed the shell and all the parts in Tinkercad, a super intuitive and complete program. This stage is the basis of the whole project, since both functionality and aesthetics depend on it. That's why I took the necessary time to achieve a design that combines both aspects.

Once the design was finalized, I printed all the pieces trying to minimize the number of supports. I used an Ender 3 Pro with:

1. 0.8 mm nozzle
2. Speed of 60 mm/s
3. Layer height of 0.28 mm
4. 25% fill

Most of the parts require mechanical strength, so I chose PLA because of its availability and because the flower is intended for indoors. If your project will be outdoors, I recommend using ABS or PETG for durability against solar radiation.

To customize the look, I printed all the pieces in white and then painted them with the colors I wanted. Finally, I sealed the paint by applying a spray varnish.

The idea is for the Aqua Floralis to work autonomously, without relying on an external source. To do this, I reused the solar panel from some inexpensive Christmas lights. Although the panel delivers around 3V, we need 5V to power the ESP8266, so an MT3608 voltage booster is incorporated.

Panel Removal:

I opened the light housing by removing the 4 screws.

I removed the solar panel, discarding (for now) the LED lights, controller and battery.

Voltage Adjustment:

I soldered the two poles of the panel to the MT3608, verifying polarity with a voltmeter.

I connected the voltmeter to the output and adjusted the potentiometer on the MT3608 until I obtained 5V (while the panel was illuminated).

Connection Preparation:

I soldered two female “du pont” wires to the output of the LM317 to facilitate connection to the ESP8266.

To tidy up the assembly, I glued the riser to the base of the panel and insulated all connections with silicone.

Note: I decided not to incorporate a battery to avoid taking up space and because the flower will only operate and send data during the day.

I assembled pieces A, B and C and placed them in order.

Cut a rubber band and thread it through the holes in the pieces, so that the start and end meet at piece C.

Repeat the process for each of the 8 petals.

Use the images to help you with the assembly.

With the petals assembled, grasp the ends of the rubber bands and attach them to either pair of side holes on the piece D (aligned parallel to the petals).

Patiently tie the bands on the inside so that they are taut, ensuring uniform shrinkage of each petal.

Cut off approximately 20 cm of the fishing line, tie one or two knots at the end and pass it through the third hole of all the pieces until you reach the piece D.

Repeat this process for all 8 petals.

Once assembled, test tighten the screws to make sure that the petals contract correctly.

The photoresistor is key to determining the time of day and thus deciding when to open or close the flower.

Voltage Divider:

Create a voltage divider using the 4.7 kΩ resistor according to the schematic (refer to the image).

Soldering:

Solder the resistor to 3 wires inside part D, which will then be connected to the ESP8266.

Tip: If the wires are a hindrance at this stage, attach them to the outside of part D, as illustrated in the last picture.

Apply some hot silicone to both the solar panel and the D-piece.

Glue the panel in the larger hole of the D-piece.

And that's it! This was one of the easiest steps of the project 😎

This step is one of the most meticulous, but fundamental to the functioning of the flower.

Carefully thread the fishing line through the holes in the piece G so that each one lines up perfectly with its respective hole.

Make sure that, at the end, all of the fishing lines converge in the center.

To facilitate the process, start with the diagonal holes.

Finally, attach piece G to the base of the solar panel using the 4 screws you removed previously.

Fit and glue the servo to piece H using hot silicone, following the reference image.

Attach the pulley (piece I) to the servo arm with a screw.

Disclaimer: Although the picture shows an earlier version of the piece H, the procedure is identical for the current version.

Align all the screws so that, when tightened, the 8 petals contract evenly.

Tie the screws together to consolidate them into a single assembly.

Connect these tansas to the pulley; I recommend using a few drops of hot silicone to secure the joint.

Attach piece G to piece D with 2 screws and, if possible, use a hot soldering iron to keep the joint fixed and immobile.

Verification: Once this step is completed, the flower mechanics should be operational. Test by uploading a test code to the ESP8266 and connect the servo to verify that it moves correctly (the code is available on my GitHub).

Before connecting the sensors to the ESP8266, let's review which inputs we are going to use:

DHT11: Temperature and humidity sensor, versatile and easy to use.

Photoresistance: Measures the light level. Important: This sensor occupies the only analog readout port of the ESP8266.

Soil Moisture Sensor:

It works by measuring the conductivity between two electrodes.

In my case, I reused an old analog-to-digital transformer and connected two stainless steel pins to it (see picture).

Calibration:

1. Place the electrodes in a pot and water as you normally do.
2. Wait a few hours.
3. If the sensor indicator light stays on, everything is OK.
4. If not, adjust the potentiometer with a screwdriver until it turns on; then wait again.
5. When the light turns off, the calibration is correct.

Tip: If you prefer to avoid assembling one from scratch, you can buy an already assembled sensor that works in a similar way.

Connect all components according to the circuit diagram (make sure you have the schematic handy).

Once the wiring is done, fix the sensors in the different places of the D-piece according to what you find most functional and aesthetic.

Attention: Make sure that nothing interferes with the mechanics of the flower.

Do not forget to pass the cable that connects the humidity probe (the electrodes) through the hole in part E so that it is exposed to the outside.

Download the code available on my GitHub.

Use the Arduino IDE to upload the code to the ESP8266.

Configure the WiFi: Don't forget to change the credentials in the code according to your own.

When starting the device, write down the IP address shown on the serial monitor. This IP address will be used to check the status of your plant via the web server.

The code has detailed comments to make it easier to understand.

Attach the cap (piece E) to piece D using 2 screws. You can apply a little silicone to reinforce the joint.

Important: The wire connecting the electrodes of the plant should be on the outside.

Connect the stem (piece F):

1. Insert it into piece E as shown in the picture.
2. Secure it with a screw, washers and nut.
3. Adjust so that the flower has the necessary mobility.

Now comes the fun part! Test your invention in the field:

1. Choose the plant that you like the most or that you think needs attention.
2. Attach the flower to the pot so that it is stable.
3. Stick the electrodes in the soil, making sure they have good contact.

Once installed, log into the web server (using the IP address noted above) to monitor the status of your plant.

➡️Every time you want to know the status of your plant, you only have to enter the IP address that the serial monitor previously gave us when loading the code in any browser. Or you can even create a shortcut so you don't have to repeat this process. The interface is clearly designed to notify you in case your plant needs water, and you can also find out without having to log in if your Aqua Floralis closes during the day. On the other hand, regardless of the external conditions, the flower will complete its phototopic cycle, that is, it detects the light level and depending on this it opens or closes the petals. It closes them at night (low light) and opens them during the day (higher light level). ⬅️

And that's it! With these steps you will have built an Aqua Floralis that combines art and technology to take care of your plants in an original and elegant way. Enjoy the process and the new life you give to your home!

If you have any questions or suggestions, leave them in the comments or check my GitHub repository, where you will also find the source code and some additional tips.

Good luck and enjoy the project! 🎉

This instructables was written entirely by a human with love ❤️