Abstract 

Growing and maintaining a flower or plant can be difficult. It takes time, dedication and care, but the end result is almost always worth it. However, if one forgets to water their plant, all of this hard work and effort goes to waste (figure 1). 

Figure 1: The flower of someone who didn't use FlowerPot Monitor (Image by Tanalee Youngblood on Unsplash) 

FlowerPot Monitor is a device which eases this issue and lets any flower-owners continue a stress and heartbreak-free life (figure 2). The device monitors your plant's environment and notifies you on the plant's condition wirelessly; alerting you immediately should your plant require attention.

Figure 2: The FlowerPot Monitor device attached to a flower pot 

Compared to other solutions, FlowerPot Monitor is relatively easy to build and later can be customised to fit the owner’s gardening needs. The receiver device has to be within twenty metres of the transmitter to display data about your plant’s environment. This makes it possible to view the information throughout your home. 

FlowerPot consists of two parts; the transmitter and receiver. The transmitter collects the readings and then sends them to the receiver via radio communication. Table 1 illustrates the cost of one FlowerPot monitor. 

Table 1: Cost of deployment of one FlowerPot Monitor device 

Project Architecture 

This section will cover the functionality and processes of the project. 

FlowerPot Monitor will continuously observe the environment that the plant is placed in, indoor or outdoor. The device monitors the following: 

• Soil moisture 
• Atmospheric humidity 
• Atmospheric temperature 

Figure 3: Diagram illustrating the project architecture 

After the transmitter (Arduino Uno reading and transmitting values) stores all the sensor readings, it sends them to the receiver (Arduino Uno receiving values and displaying them) via radio frequency (RF) communication where the data is displayed on an LCD.  

Transmitter 

The transmitter must pack all the three integer variables into a unit8_t variable and then send the data over RF communication to another Arduino Uno equipped with a receiver. 

The transmitter works on batteries. 

Receiver 

When the data is received, the receiver must process the data and convert it back into the three variables that were sent. 

The receiver works on batteries. It must be in a twenty-metre range to display data from the transmitter (given that there are no objects, such as doors, blocking the path between them). 

User Feedback 

Figure 4: LCD display before watering 

The user receives feedback about the plant’s environment through an LCD display attached to the receiver. Figures 4 and 5 show the display in action. 

Figure 5: LCD display after watering 

Making the Project 

This section will talk about the steps needed to construct the project from start to finish. 

Step 1: Required Apparatus? 

Figure 6: All components required to build the receiver 

This project requires two circuits; one for the transmitter and one for the receiver. The BOM can be seen above. 

Figure 7: All components required to build the transmitter 

Step 2: Connecting the Circuit 

Figure 8: Receiver schematics 

The next step is to connect the circuit; the circuit diagrams (figures 8 and 9) illustrate the circuits of the receiver and transmitter respectively.  

Figure 9: Transmitter schematics 

Step 3: Acknowledging the Code 

This project consists of two different code executables; one for the receiver and the other for the transmitter. Both executables consist of many functions, these are explained below. Please clone the code from the GitHub repository to follow along. 

Read Values (Receiver) 

This method will read the unit8_t variable that the transmitter sends and convert it into three variables: temperature, humidity and soil moisture. 

Display Temp and Hum and Display Soil Moisture (Receiver) 

These functions display the received and processed data on the LCD. The plant's soil moisture is displayed as a percentage (100 being fully liquid) as well as the temperature and humidity of the plant’s environment. 

Read Temp, Humidity, and Soil Moisture (Transmitter) 

First, the transmitter will read the values from the DHT11 temperature and humidity sensor and then the soil moisture sensor. 

Send Data (Transmitter) 

This piece of code is part of the void loop, after the transmitter reads the values from the sensors, the microcontroller packs all the data into a unit8_t variable and sends it via RF communication to the receiver. 

Step 4: Setup 

Ensure that the circuits are correctly wired, connect both devices (transmitter and receiver) to a computer and upload the code from the GitHub repository. Make sure that you upload the receiver code to the receiver board and vice versa. If you have plugged both microcontrollers to the computer via separate ports then change the USB port on your computer to the other board and upload the transmitter section of the code. Now you are all set! 

Step 5: Constructing the Enclosure 

I have designed an enclosure for the receiver board out of cardboard, I decided that the transmitter does not need a cover. It is very easy to make this enclosure. 

Required Apparatus 

All you need for this enclosure are scissors, some tape and a piece of thin cardboard, approximately 200mm by 180mm. 

Shaping the Parts 

Following the attached schematics, shape the piece of cardboard into smaller pieces using a scissors or guillotine. You can verify your enclosure against figure 10. 

Figure 10: Enclosure parts cut out 

Cut Top for Screen 

The top cover is divided into two parts. A gap in the centre reveals the LED and screen, we need to cut a space on both cover pieces for the screen. Measure your screen and then cut out an appropriate amount. 

Figure 11: A space is cut in the front cover to reveal the LCD 

Putting It Together 

Now it is time to put all the parts together, the following steps will walk you through this process: 

• Firstly glue the Arduino Uno and breadboard to the bottom enclosure piece 

Figure 12: Arduino Uno and breadboard glued to bottom enclosure piece 

• Next we will place the cover on top, ensure to cut a hole for the power input on the Arduino Uno. Glue the larger cover piece on the right and the smaller on the left, ensure that the LED is in the gap between. 

Figure 13: The circuitry is covered by the front enclosure piece 

Now the project is done! Figure 14 shows the transmitter and receiver together. 

Figure 14: receiver (left) and transmitter (right) together 

Conclusion 

FlowerPot Monitor observes your plant’s environment using an array of sensors. This data is displayes wirelessly on an LCD so that one doesn’t have to worry about when to water their plant. 

I was inspired to build FlowerPot Monitor because my friend, Rafa, who lives in Mexico was having a lot of trouble with keeping his plants alive. My device makes it easier for him to know when he needs to water his plants. I hope that others like him can implement FlowerPot Monitor in their lives to effortlessly monitor their plants.