ICStation team introduce you how to DIY this temperature﹠ humidity ﹠smoke alarm system based on ICStation Mega compatible with Arduino.The working voltage of this system is DC5V.It can measure the current temperature, humidity and smoke. It can display real-time data by the LCD and can realize the sound and light alarm when in the dangerous temperature and humidity. It is a simply and easily to operate monitoring alarm system about temperature humidity and smok

1. DIY Temperature Humidity Smoke Monitoring Alarm﹠ ﹠
System Based on Arduino
ICStation team introduce you how to DIY this temperature humidity smoke alarm﹠ ﹠
system based on ICStation Mega compatible with Arduino.The working voltage of
this system is DC5V.It can measure the current temperature, humidity and smoke. It
can display real-time data by the LCD and can realize the sound and light alarm when
in the dangerous temperature and humidity. It is a simply and easily to operate
monitoring alarm system about temperature humidity and smoke.
Functions:
1.When connect to the power supply, after the initialization of hardware, the LCD will
display the current temperature ,humidity and smoke volume
2.NO.1 key, the LCD will turn the page and enter the dangerous temperature setting
page.At this time, press NO.2 key once, the dangerous temperature will add one. If
the actual temperature is higher than the setting value, the gree LED will light, at the
same time the buzzer will alarm. When the actual temperature is lower than the
dangerous temperature, the LED will go out and the buzzer will stop alarm.
3.When the LCD display stays on the second page , we press the NO.1 key, you will
see the LCD will turn page to the third page and enter the dangerous humidity setting
page.At this time, press the NO.3 key, the dangerous humidity will add one.If the
actual humidity is higher than the setting value, the red LED will light,at the same
time the buzzer alarms. When the actual humidity is lower than the dangerous
humidity, the LED will go out and buzzer stop alarming.
4.
Components List:
1.ICStation ATMEGA2560 Mega2560 R3 Board Compatible Arduino
http://www.icstation.com/product_info.php?products_id=3517
2.DHT11 Digital Humidity Temperature Sensor
http://www.icstation.com/product_info.php?products_id=1398

2. 3.MQ-2 Gas Sensor Module Smoke Methane Butane Detection for Arduino
http://www.icstation.com/product_info.php?products_id=3025
4.1602A HD44780 Character LCD Display Module LCM Blue Backlight
http://www.icstation.com/product_info.php?products_id=1419
5.LED Light Emitting Diode
http://www.icstation.com/product_info.php?products_id=3061
6.Tact Switches 4 Legs
http://www.icstation.com/product_info.php?products_id=949
7.1K ohm 1/4W 1% Accuracy Metal Film Resistor
http://www.icstation.com/product_info.php?products_id=74
8.100K ohm 3296W Trim Pot Trimmer Potentiomete
http://www.icstation.com/product_info.php?products_id=700
9.Jumper wires:
http://www.icstation.com/advanced_search_result.php?
keywords=jumper+wire&x=23&y=13
10.3P DuPont Line:
http://www.icstation.com/product_info.php?products_id=3269
11.5 Voltage power supply
12.Active Buzzer Module for Arduino
http://www.icstation.com/product_info.php?products_id=2512
13.830 Point Solderless PCB Bread Board MB-102 Test DIY
http://www.icstation.com/product_info.php?products_id=1450

3. Schematic Diagram

5. （1）From ICStation Mega development board, introduce the 5V power supply and GND to the
bread board. The red one as power supply wire and black one as the GND wire.
Introduce in power supply wire and GND wire
2.Plug in the LCD 1602 and potentiometer to the bread board and connect it to the power supply
and GND
Put in 1602 LCD
（3）Plug in the DHT11 humidity and temperature sensor module to the bread board and connect

6. to the ICStation Mega development board, power supply and GND
Put in DHT11 temperature and temperature sensor
(4)Connect MQ-2 Gas Sensor Module to the ICStation Mega development board,power supply
and GND.
Put in MQ-2 Gas Sensor Module
（5） Plug in the active buzzer module to the bread board and connect it to the ICStation Mega
development board and power supply and GND
Put in active buzzer module
（6）Plug in the switch, resistor to the bread board and connect it to the ICStation Mega
development board and GND
Put in switch and resistor

7. （7） Plug in the LED light emitting diode to the bread board and connect it to the ICStation
Mega development board ,power supply and GND
Put in LED light emitting diode
The experimental effect:
First, connect to the power supply,the LCD will display the first page of current
temperature ,humidity and smoke volume.
When we press the NO.1 key, the LCD will turn the page and enter the dangerous
temperature setting page.At this time, press NO.2 key once, the dangerous
temperature will add one.When we at the dangerous temperature setting page, we
press the NO.1 key again, you will see the LCD will turn to the first page,at this time
use your hand to touch DHT11 humidity and temperature sensor module,you can
observe that the temperature and humidity increase gradually( Because the humidity
and temperature of hand is higher than the air. When the temperature is higher than
the temperature we set, the green LED will light and the buzzer will alarm. When the

8. humidity is larger than the dangerous humidity we set, the red LED will light and the
buzzer will alarm.
Code for your reference
http://www.icstation.com/newsletter/eMarketing/alarm system code.txt