Now let's see the hardware to build this project. Since the theme for this project is to use the Seeeduino XIAO and Grove sensors, here is the hardware required to do this project.

List of Hardware

1. Seeeduino XIAO

What is Seeduino XIAO? As the name goes, XIAO (小 in Chinese), is one of the smallest members of the Seeduino family. This board carries the powerful ATSAMD21G18A-MU which is low-power microcontrollers. Despite being small in size, this board has good performance in processing but needs less power. It is designed in a tiny size and can be used for wearable devices and small projects.

Below are the features of this product.

• Powerful CPU: ARM® Cortex®-M0+ 32bit 48MHz microcontroller(SAMD21G18) with 256KB Flash,32KB SRAM.
• Flexible compatibility: Compatible with Arduino IDE.
• Easy project operation: Breadboard-friendly.
• Small size: As small as a thumb(20x17.5mm) for wearable devices and small projects.
• Multiple development interfaces: 11 digital/analog pins, 10 PWM Pins, 1 DAC output, 1 SWD Bonding pad interface, 1 I2C interface, 1 UART interface, 1 SPI interface.

And next are the specifications of this product.

That is the main component of this project. Now let us see the rest of the components needed to build this project.

2. Expansion Board Base for XIAO

The expansion board base for XIAO is a powerful board. It enables to building of prototypes and projects with ease and quick way. Its rich peripherals include OLED, RTC, expandable memory, passive memory, passive buzzer, RESET/User button, 5V servo connector, and multiple data interfaces. Below are the features of this board:

Features:

• Quick Prototyping: Easy debug and Reset with RESET button and SWD pin led out to the male header.

• Rich peripherals: OLED display, RTC, expandable memory space, passive buzzer, user button, onboard battery management chip.

• No Soldering Needed: All pins are led out. Convenient plug-and-play Grove connectors support multiple data protocols, including IIC, UART, and Analog/Digital.

• Circuit Python Supported: Well supports circuit Python. MicroSD card slot enables memory space to expand, making it possible to allocate more libraries needed in prototyping and project building.

• Mini Size: Compact and elegant with only half Raspberry Pi 4 size, especially suitable for projects that require mini size.

Specification:

Below is the hardware overview of the expansion board.

And below is the rear view of the board.

On this rear side, there is a MicroSD card slot and RTC battery holder. And below is the pinout diagram.

3. Grove - soil moisture sensor

To monitor the soil moisture level we will be using the Grove soil moisture sensor. This sensor can be used to check if there is water around the sensor.

Below is the specification of the sensor:

4. Grove - temperature & humidity sensor

The next sensor that we would like to see is the temperature and humidity sensor. For this, we will use the SHT40. Below is the specification of this sensor.

5. Grove - VOC Gas Sensor (SGP40)

The Grove - VOC gas sensor is an innovative environmental sensing module. This sensor excels in transforming raw sensor signals into standardized digital signals for seamless integration into the existing system. Moreover, this sensor module provides a versatile solution for tracking and monitoring indoor air quality since it has the capability to perform high-quality VOC measurements in real-time. 

Below are the features of the sensor:

• Utilizes the Sensirion SGP40 sensor for reliable VOC detection.
• Easy integration into the Grove ecosystem, simplifying the wiring and coding process.
• Provides real-time VOC measurements for accurate air quality assessment.
• Communicates via I2C interface, allowing for efficient data transfer.
• Compact and modular design, perfect for embedding in various applications.

This is the specification of the sensor

• Operating Voltage: 3.3/5V
• Interface: I2C
• Dimensions: 20x40mm

6. Grove - Relay

The Grove-Relay is a digital normally open switch that controls a relay capable of switching much higher voltages and currents than your normal Arduino boards. There is an indicator LED on the board. When set to HIGH, the LED will light up and the relay will close allowing current to flow. The peak voltage capability is 250V at 10 amps.

The specification of the relay is as below:

• Operating Voltage: 3.3V / 5V
• Operating Current: 100mA
• Max. Switching Voltage: 250VAC/30VDC
• Max. Switching Current: 10A
• Dimensions: 42mm x 24mm x 19.50mm
• Grove-compatible module
• 3-pin connection: Logic signal – Vcc – GND
• 2-way screw terminal: COM – NO
• Breaking capacity: 10 A / 250 Vac
• Contact indicator: LED

7. Micro Submersible Water Pump DC

Micro Submersible Water Pump DC 3V-5V, which can be easily integrated into your water system project. The water pump works using the water suction method which drains the water through its inlet and releases it through the outlet. You can use the water pump as an exhaust system for your aquarium and controlled water flow fountain.

These are the sensors that I have planned to use in building this project. In the next part, we shall see the software that i have planned to use.