At Arduino Expert, we specialize in Product Design and Development, Arduino Project Development, Custom Electronics Project Development, and Embedded Systems Development for unique client requirements. In this client project, we developed a Smart Climate Controlled Tub System with Arduino Nano 33 IoT to automatically create and maintain an ideal environment inside an enclosed tub for Mushroom Growing Chambers/Seed Germination and Plant Propagation Chamber. The original requirement was to build a system that could monitor humidity, temperature, and CO2, then control external devices such as a humidifier, air pump, LED lights, and heat mat through relays to keep the internal conditions stable and suitable for the intended use.
This project was designed as a compact and intelligent environment automation system that reduces manual effort and improves consistency. Instead of checking conditions and switching devices on or off manually, the system continuously reads sensor data and responds automatically according to programmed control logic. For example, humidity control is achieved by operating the humidifier and air pump together when humidity falls below the required level, while the air pump can also work independently when CO2 becomes too high. Similarly, the heat mat is activated when the temperature drops below the target range, and the LED lights follow a timed 12-hour ON / 12-hour OFF cycle. The requirement also included an LCD display for live readings and output status indication, which makes the system easier to monitor and operate.
Using the Arduino Nano 33 IoT as the main controller, along with a DHT11 sensor, CCS811 CO2 sensor, I2C LCD, 4-channel relay module, and 3 push buttons, this project became a practical example of a custom embedded climate-control solution. It demonstrates how an Arduino-based automation system can be engineered for real-world environmental control applications where stable conditions are important. This project is also a strong representation of our expertise in building custom electronics solutions, sensor-based control systems, and smart embedded prototypes for clients who need tailored hardware and firmware development.
Objective of Smart Climate Controlled Tub System
The main objective of this project was to build a smart enclosed-environment control system capable of maintaining favorable conditions inside a tub. The system was designed to:
- Monitor temperature
- Monitor humidity
- Monitor CO2 concentration
- Control humidification
- Control fresh air exchange
- Control heating
- Control lighting cycle
- Provide live readings on an I2C LCD
- Offer local control through push buttons
This automation approach helps reduce manual effort while improving consistency and reliability in climate-sensitive applications.
Checkout our related project: Arduino Smart Garden System || Irrigation, Sprinklers, Lighting, Music Control and Scheduling
Hardware Used in Smart Climate Controlled Tub System Project
For this client project, we used the following major components:
- Arduino Nano 33 IoT
- DHT11 Sensor for temperature and humidity sensing
- CCS811 CO2 Sensor for air quality / equivalent CO2 monitoring
- I2C LCD Display for real-time readings and system status
- 4-Channel Relay Module
- Humidifier
- LED Lights
- Heat Mat
- Air Pump
- 3 Push Buttons for local user interaction and control
- Power Supply/Battery
This combination created a compact but highly capable Arduino-based automation system suitable for a climate-controlled enclosure.
How the Smart Tub Climate Control System Works?
The working principle of this project is based on continuous sensing and automatic device control.
1. Temperature Monitoring and Heat Control
The DHT11 sensor continuously measures the internal temperature of the tub. When the temperature falls below the defined threshold, the system activates the heat mat through the relay module. Once the desired temperature range is restored, the heating output is turned off.
This ensures that the internal environment remains stable and warm enough for the intended application.
Checkout Our Temperature Control Project: Industrial Oven and PID Control with Arduino
2. Humidity Monitoring and Humidifier Control
Humidity is also measured through the DHT11 sensor. When the humidity level drops below the target level, the system turns on both the humidifier and the air pump so that moisture can be delivered and circulated effectively inside the tub. The original requirement specified that the humidifier and air pump should work together whenever humidity falls below 75%.
This creates a more uniform and responsive humidity-control mechanism inside the enclosed space.
Checkout Our IoT Water Pump Control by using ESP32 and Blynk App Project
3. CO2 Monitoring and Ventilation Control
The CCS811 sensor is used to monitor CO2 concentration. If CO2 rises above the allowed level, the system activates the air pump independently to improve air exchange. The requirement specifically stated that the air pump should run alone when CO2 becomes too high.
This helps maintain air quality and prevents the enclosed environment from becoming overly stagnant.
4. Timed Lighting Control
The lighting system is managed through relay control and timed logic. The client required a 12-hour ON / 12-hour OFF cycle for the LED lights. This makes the project suitable for applications where periodic illumination is required.
5. LCD-Based Live Monitoring
An I2C LCD is included to display real-time values and system information. The original brief requested an LCD to view sensor readings and show which outputs are active. This improves usability by allowing the operator to monitor the system without connecting it to a computer.
6. Push Button Based User Interaction
The project also includes 3 push buttons, allowing local interaction with the system. In the implemented control logic, these buttons support on-device operation and mode selection, making the system more practical for everyday use.
Key Features of Smart Tub Monitoring and Control System
Automated Environmental Control
The system automatically reacts to climate conditions without requiring constant manual intervention.
Multiple Sensor Integration
It combines temperature, humidity, and CO2 sensing in a single embedded solution.
Relay-Based Output Control
A 4-channel relay module allows safe control of external AC/DC devices such as humidifiers, air pumps, lights, and heat mats.
Local Display Interface
The I2C LCD provides a simple and user-friendly way to observe live environmental readings and system activity.
Button-Based Local Operation
Three onboard push buttons improve usability and make on-site interaction easier.
Compact Embedded System Design
Using the Arduino Nano 33 IoT makes the project compact, modern, and suitable for future smart upgrades.
Circuit Diagram of Automated Smart Tub Climate Controller Project with Arduino Nano 33 IoT
Arduino Code for Arduino Smart Grow Tub Controller
#include "DHT.h"
#define DHTPIN 9
#define DHTTYPE DHT11 // DHT 11
DHT dht(DHTPIN, DHTTYPE);
// Laibrary of I2C LCD Module
#include <LCD-I2C.h>
LCD_I2C lcd(0x27, 20, 4); // Default address of most PCF8574 modules, change according
#include "Adafruit_CCS811.h"
Adafruit_CCS811 ccs;
int value;
// RTC laibrary
#include <RTCZero.h>
/* Create an rtc object */
RTCZero rtc;
int Time1=6; // set time here
int Time2;
// variable
unsigned long prv;
unsigned long prv2;
unsigned long prv3;
/* Change these values to set the current initial time */
const byte seconds = 0;
const byte minutes = 0;
const byte hours = 16;
/* Change these values to set the current initial date */
const byte day = 15;
const byte month = 6;
const byte year = 15;
//variable to get data from RTC
int Hour;
int minute;
int second;
//Initialized button pins
int btn1=2;
int btn2=3;
int btn3=4;
int mode=0;
// Initialized logic variables
bool flag1=false;
bool flag2=false;
bool flag3=false;
bool Mode=false;
bool Temp1=false;
bool Temp2=false;
bool Temp3=false;
// you can set here shold value of Mode : 1
float temp_Shold_M1=20;
int Humid_Shold_M1=75;
int Carbon_Shold_M1=3000;
// you can set here shold value of Mode : 2
float temp_Shold_M2=26;
int Humid_Shold_M2=75;
//int Carbon_Shold_M2=2000;
// you can set here shold value of Mode : 3
float temp_Shold_M3=20;
int Humid_Shold_M3=90;
//int Carbon_Shold_M3=2000;
//Here you can declair pinout of Relay
int air_pump=5;
int humidfire=6;
int heat_mat=7;
int led_lights=8;
void setup() {
Serial.println(F("DHTxx test!"));
dht.begin();
if(!ccs.begin()){
Serial.println("Failed to start sensor! Please check your wiring.");
while(1);}
while(!ccs.available());
Serial.begin(9600);
//Initialized lcd
lcd.begin();
lcd.display();
lcd.backlight();
lcd.clear();
lcd.setCursor(1, 1);
lcd.print("All Modes off ");
// declair button as an INPUT_PULLUP
pinMode(btn1,INPUT_PULLUP);
pinMode(btn2,INPUT_PULLUP);
pinMode(btn3,INPUT_PULLUP);
//declair relays pins as an output
pinMode(air_pump,OUTPUT);
pinMode(humidfire,OUTPUT);
pinMode(heat_mat,OUTPUT);
pinMode( led_lights,OUTPUT);
// Initialized relay
digitalWrite(air_pump,HIGH);
digitalWrite(humidfire,HIGH);
digitalWrite(heat_mat,HIGH);
digitalWrite( led_lights,HIGH);
// initialize RTC module
rtc.begin();
// Set the time
rtc.setHours(hours);
rtc.setMinutes(minutes);
rtc.setSeconds(seconds);
// Set the date
rtc.setDay(day);
rtc.setMonth(month);
rtc.setYear(year);
Time2= Time1+12;
if (Time2>=24){Time2=Time2-24;}
// you can use also
//rtc.setTime(hours, minutes, seconds);
//rtc.setDate(day, month, year);
}Applications of the Custom Automated Tub Climate Controller
This project can be adapted for many controlled-environment use cases, such as:
- Mushroom growing chambers
- Seed germination chambers
- Plant propagation tubs
- Mini greenhouse enclosures
- Terrarium climate management
- Experimental environmental chambers
- Smart incubation support systems
- Educational embedded systems projects
- Sensor-based automation demonstrations
- Custom small-scale climate automation products
Because the system monitors environmental conditions and responds automatically, it is a practical solution for any small enclosed space requiring temperature, humidity, air exchange, and timed lighting control.
Why This Project Matters?
Many environmental control tasks are still performed manually, which leads to inconsistency, wasted effort, and inaccurate climate management. This project solves that problem by combining sensing, logic, relay switching, display monitoring, and local control into one efficient embedded system.
For clients who need a custom electronics solution rather than a generic off-the-shelf controller, projects like this demonstrate the value of tailored engineering. At Arduino Expert, we work closely with clients to transform requirements into real, working systems through Product Design and Development, Embedded Systems Development, and Custom Electronics Project Development.
Conclusion
The Smart Climate Controlled Tub System with Arduino Nano 33 IoT is a practical and intelligent Arduino project developed to automatically maintain the desired environment inside an enclosed tub. By combining temperature, humidity, and CO2 sensing with relay-based control of a humidifier, air pump, heat mat, and LED lights, this system provides a compact yet highly effective climate automation solution. The original project requirement centered on creating the perfect environment inside a tub by automating humidity, ventilation, heating, and timed lighting, while also displaying live readings on an LCD.
This project demonstrates how Custom Electronics Project Development and Embedded Systems Development can solve real-world environmental control challenges in a smart, automated, and user-friendly way. With the addition of an LCD interface and push button control, the system becomes even more practical for local operation. It is also a strong example of how Product Design and Development can turn a client’s concept into a functional embedded solution tailored to a specific application.
Do you Need Custom Climate Control System Project?
If you need this Custom Climate Control System Arduino Project with or without Modifications or Customization then you can contact us through WhatsApp.
Learn More about the services we offer.
Frequently Asked Questions (FAQs)
What is the Smart Climate Controlled Tub System with Arduino Nano 33 IoT?
The Smart Climate Controlled Tub System is an Arduino-based automation project designed to create and maintain a controlled environment inside a tub or enclosed chamber. It monitors temperature, humidity, and CO2 levels and automatically controls connected devices such as a humidifier, air pump, heat mat, and LED lights through relays. The original project requirement was to create the perfect environment inside a tub using humidity, temperature, and CO2 sensing with automated relay-driven outputs.
What sensors are used in this climate control system?
The project uses:
DHT11 sensor for temperature and humidity monitoring
CCS811 sensor for CO2 monitoring
These sensors help the system make automatic control decisions based on environmental conditions.
Is this project suitable for custom product development?
Yes. This project is a strong example of Product Design and Development, Custom Electronics Project Development, and Embedded Systems Development. It can be further expanded with IoT connectivity, data logging, remote monitoring, and advanced parameter control.
Can this project be upgraded in the future?
Yes. Since it is based on Arduino Nano 33 IoT, the system can be upgraded with:
Wi-Fi monitoring
Mobile app control
Cloud data logging
Alerts and notifications
Advanced touchscreen interface
More accurate sensors
Custom user settings
