IoT based Soil Moisture Monitoring System using ESP32

Components Required

• ESP32
• Soil Moisture Sensor
• OLED Display
• Connecting Wires

OLED Display

The OLED displays are one of the most common and easily available displays for a microcontroller. This display can easily be interfaced with microcontroller using IIC or using SPI communication and has a good view angle and pixel density which makes it reliable for displaying small level graphics. It is compatible with any 3.3V-5V microcontroller, such as Arduino. The OLED display comes with a powerful single-chip CMOS OLED driver controller – SSD1306 that handles the entire RAM buffering. The SSD1306 driver has a built-in 1KB Graphic Display Data RAM (GDDRAM). We previously interfaced OLED with ESP32.

Specifications

• OLED Driver IC: SSD1306
• Resolution: 128 x 64
• Visual Angle: >160°
• Input Voltage: 3.3V ~ 6V
• Pixel Colour: Blue
• Working temperature: -30°C ~ 70°C

Circuit Diagram

Circuit Diagram for ESP32 Moisture Sensor is given below.

We are interfacing the ESP32 with Soil Moisture Sensor and OLED Display. Vcc and GND pin of the Soil Moisture sensor is connected to 3.3V and GND of ESP32, while the Analog pin of Moisture sensor is connected to the VP pin of ESP32. I2C mode is used to connect the OLED display Module (SSD1306) with ESP32. Connections between ESP32 and OLED Display are given as:

Adafruit IO Setup for ESP32 Soil Moisture Sensor

Adafruit IO is an open data platform that allows you to aggregate, visualize, and analyze live data on the cloud. Using Adafruit IO, you can upload, display, and monitor your data over the internet, and make your project IoT enabled. You can control motors, read sensor data, and make cool IoT applications over the internet using Adafruit IO. We previously used Adafruit with ESP32 and also built many IoT based applications using Adafruit.