Monitoring and Control System Development on IoT-Based Aeroponic Growth of Pakcoy ( Brassica rapa L.)

Abstract


Introduction
Aeroponics is a farming technology by hanging plant roots in the air and growing them in a moist environment and not using soil.Aeroponics can be done anywhere because of the planting technique without soil and with roots hanging in the air.Aeroponics means air empowerment where the word aeroponics comes from the word aero which means air and ponus which means power, so aeroponics has the meaning of utilizing air (Wicaksono et al., 2017).Aeroponics is a way of growing plants by jTEP JURNAL KETEKNIKAN PERTANIAN, hanging them in the air and growing them in a moist environment without soil.Because the roots of the plant hang in the air, it is possible to grow almost anywhere using usable cubic space (Reyes et al., 2012).Even though the area used is not too large, the productivity of the land is still high.Aeroponics is a good method because it can produce droplets in the form of fine liquid droplets like mist.The aeroponic method has a nutrient delivery speed of up to 135% faster than hydroponics and normal plant cultivation (Kanisius, 1992).Aeroponics is also a development of the deficiencies that exist in hydroponic methods such as plant roots that are constantly soaked in nutrients thereby reducing the level of aeration and oxygenation of plant roots.Besides another drawback of hydroponics is growth that is not optimal because plant roots will have difficulty absorbing nutrients because the components of the nutrient solution require special care so that they do not have a toxic effect on plants.One way to overcome this is by using various sensors to monitor environmental factors that have an influence on plant growth and development.Research conducted by Yazid et al. (2020), regarding the prototype of IoT-based aeroponic cultivation observations.In this study, researchers used the Arduino Wemos D1R2 microcontroller using several sensors to control and monitor temperature and humidity, the water level in the grow box and the acidity (pH) of nutrients (Putri et al., 2022).However, the value for humidity used in the system made by researchers is > 99% so the humidity reading is very high, so the sensor will only read 100% humidity and does not match the needs of the plants.Iriani et al. (2018) regarding an aeroponic monitoring system based on IoT, researchers use a Single Board Computer where the microcontroller used is ATmega16.Researchers only monitor temperature and humidity using the DHT11 sensor (Putri et al., 2023).Research conducted by Indrajaya et al. (2019), researchers created a control system for automatic monitoring of nutrient concentrations in aeroponics with a TDS sensor.The test results obtained by the researchers were in the form of sensor calibration results reaching 99% and having a measurement accuracy and precision of 95%.

Research conducted by
However, the devices made by the researchers still use UTP (Unshielded Twisted Pair) cables and suggest that communication can be done wirelessly (Wireless) to make it more practical.The objective of this study is to design a prototype aeroponic system equipped with temperature and humidity control, control of the height of the nutrient solution and monitoring the concentration of plant nutrients based on the internet of things on pakcoy (Brassica rapa L.) plants, designing a control system on internet-based aeroponics of things on pakcoy plants (Brassica rapa L.), and testing the performance of the control and monitoring control system on an internet-based aeroponic system of things on pakcoy plants (Brassica rapa L.).

Materials and Methods
The method used in this study is an experimental method by making aeroponic prototypes and control systems to monitor and control temperature and humidity in grow boxes made of container boxes, nutrients and nutrient solution heights in buckets.

Aeroponic Prototype Design
The aeroponic prototype design was made as a method of farming to save water and nutrients that will be given to plants.The grow box used in this study is made of a container box which has 24 planting holes located on the lid of the box.The planting hole has a distance between plants of 20 cm with the lid of the container box attached with a netpot with a diameter of 5 cm.The grow box is 110 cm long, 80 cm wide and 50 cm high.The box is raised with wood so that the plants are not exposed to rainwater splashes which can cause damage to the plants.On the side of the box there is also a hose and pipeline from the nutrient bucket to the grow box with a pipe size of 2.54 cm.On the side of the grow box there is a series box containing a control system and a nutrient bucket to distribute nutrients to the grow box which consists of nutrient A and nutrient B solutions that have been concentrated and then mixed with water to the required nutrient concentration.An overview of the tool can be seen in

Control System Design
The control system is made to facilitate monitoring and control of temperature and humidity control, the level of nutrient solution and the concentration of plant nutrients in grow boxes and buckets.The hardware required for the control system consists of components such as NodeMCU V3 as a microcontroller used in the system and connected to the Blynk application via an internet connection.The circuit schematic can be seen in Figure 5.The aeroponic system is made using a pre-planned design.The plants will then be placed in a grow box that has been equipped with a planting hole.Plant holes on the lid of the box made as many as 24 plant holes.Each hole will be placed in a netpot with plants that have been sown on rockwool as a growing medium.The inside of the box is fitted with a pipe as a distributor of nutrients which is equipped with 10 mist nozzles.The grow box is also equipped with a jet pump to pump water into the pipe, the pump used in this system is a jet pump with a pressure of 100 Psi in order to produce fog at the nozzle because the aeroponic system used is the High Pressure Aeroponic (HPA) system and the TDS sensor to see plant nutritional value.

Plant Preparation and nutrition
Preparation of the pakcoy plants begins with preparing the pakcoy seeds which are sown using rockwool for 14 days, by placing the pakcoy in a dark place for 1 to 2 days until sprouts appear, the next day the pakcoy seeds are given light 4 hours per day.After 14 days after sowing the seeds were transferred to the netpot and put in each planting hole provided in the grow box.AB Mix nutrition is given to plants starting from sowing the seeds when entering 7 days after sowing as much as 300 ppm until the plants are transferred to the aeroponic installation, then nutrition is given according to the needs of the plants per week until harvest later.Fertilizer was also applied to control plants when mixing with soil and 2 weeks after planting.

Determination of Set Point Value
The optimal temperature for pakcoy growth is 20 o C to 25 o C with 80% to 90% humidity (Sariayu et al., 2017).The distance between the water level in the grow box and the ultrasonic sensor is 5 cm and it is maintained that the availability of nutrients from the bottom of the bucket is not less than 10 cm.
Good nutrition for pakcoy plants is 1000 ppm-1400 ppm so that when the concentration value does not match this value, you can add AB Mix nutrients or add water.These values will then be used as a setpoint in this study.

Tool Reading Response Time
Calculating how much power is used in running the control system is needed by determining the The control system that has been properly operated is then connected to the blynk application.This application serves as an Internet of Things (IoT) platform.The blynk application connection is made with the token aunth code obtained from the blynk application when logging in and opening a new worksheet as an interface.After that the code obtained will be entered into the microcontroller to be connected.

Monitoring
Monitoring of temperature and humidity is carried out at 08.00 AM, 12.00 AM and 04.00 PM every day.Data retrieval is done by looking at the readings from the DHT22 sensor displayed on the blynk application.Monitoring the height of the nutrient solution in the bucket is carried out every day by looking at the readings on the HC-SR04 ultrasonic sensor displayed on the blynk application.
Monitoring is carried out to determine the height of the nutrient solution in the bucket, so that when the bucket starts to empty there will be a notification on the smartphone, so we have to add nutrients manually.Data collection was carried out once every 30 days.Observation and data collection is carried out based on the TDS sensor and TDS meter measurements.

Sensor reading accuracy.
Testing the accuracy of sensor readings is carried out to find out whether the sensor is working properly or not.Testing the accuracy of readings is done by comparing data readings using the DHT22 sensor with a thermohygrometer.The accuracy of sensor readings can be determined by equation 2.

Data analysis
The results of the data that have been obtained in the study, then carried out a descriptive statistical analysis of the observations.Calculations are performed based on the results obtained by finding the mean and regression analysis.

Results and Discussion
Aeroponik is made of a container box that is used as a grow box which has a lid with a box length and width of 110 cm x 80 cm and a height of 50 cm.The lid of the box has a planting hole that has been installed with a net pot of 24 planting holes with a spacing of 20 cm x 20 cm.The following results of the design of the Aeroponic prototype can be seen in Figure 6.Inside the box there is a pipe that is used to distribute nutrients directly to plant roots.There are two interconnected pipes that are attached between the 2 plants so that they can hit the roots of the two plants.On the pipe section, 10 nozzles are also installed which have a diameter of 0.7-0.9m with a nozzle hole size of 0.5 mm.The design results of the pipe can be seen in Figure 7.
All components such as sensors and microcontrollers are combined into a control system that can maintain and condition aeroponic conditions to remain stable.The control system series is connected to a smartphone using the blynk application to display data read by the sensor.The following results of the control system circuit can be seen in Figure 8.The blynk application is a platform that can be used to support IoT-based projects.The blynk application can be found on the Play Store and App Store.After the blynk application is downloaded, first register using an email to get an auth token code.The auth code is entered into the Arduino IDE application programming to connect to blynk and NodeMCU V3.The script code for connecting the blynk application with the Arduino IDE application can be seen in Figure 9.

Figure 1 .
Figure 1.The DHT22 sensor, TDS sensor and ultrasonic sensor are mounted on the inside of the grow box as shown in Figure 2.

Figure 3 .
Figure 3. Irrigation Pipelines Schematic of sensor placement and distribution of nutrition from the nozzle can be seen in Figure

Figure 4 .
Figure 4.Schematic of Sensor Placement and Nutrition from the Nozzle

Figure 7 .
Figure 7. Pipe and Nozzle Design Results

Figure 9 .
Figure 9. Script Code Auth Token, WiFi Name and Password Monitoring and control of this study used widgets such as gauges which function to display readings from each sensor used, levels which function to see the level of nutrient solution in 2D form, charts which function to display sensor reading data presentations in the form of graphical displays and notifications.which serves to display information related to nutritional conditions and the height of the nutrient solution in the bucket.The user interface display can be seen in Figure 10.

Figure 10 .
Figure 10.Script Code Auth Token, WiFi Name and Password The main components in systems that require electrical power consist of the NodeMCU V3 and the jet pump.The input and output voltage limits contained in NodeMCU V3 are 3.3 volts to 5 volts with a current required for one pin of 40 mA.The total pins used in the control system are 4 pins with