Week 7 Final Year Project 2

Date: 7 March 2018

Time: 3.00 p.m

Place: Library



Objectives:

 - To find the connection of the MQ-135 gas sensor and DHT22 temperature and humidity sensor to the ESP8266 module.



Activities:

-  Today, I want to find the connection of the gas sensor and temperature sensor to the ESP8266 module. Means that, there are two inputs for the sensors to the ESP8266. So, I was choose D1 and D2 as the inputs known as GPI05 (D1) and GPI04 (D2). For the MQ-135 gas sensor is connect to the GPI05 and for the temperature sensor is connect to the GPI04. The ESP8266 has 30 pins inputs and one USB power output. The special of this hardware is the ESP8226 can has same function of the Arduino Uno R3 but it have the wifi module to connect to the wifi. 

 

The 30 inputs pins in the ESP8266

-  For MQ-135 gas sensor features are wide detecting scope, stable and long life, fast response and high sensitivity and simple drive circuit. The application used for in air quality control equipments for buildings/office, are suitable for detecting of NH3, NOx, alcohol, Benzene, smoke, carbon dioxide gas. The resistance value of MQ-135 is difference to various kinds and various concentration gases. So, when using this components, sensitivity adjustment is very necessary. The recommendation that calibrate the detector for 100ppm NH3 or 50 ppm Alcohol concentration in air and use value of Load resistance about 20k ohms (10k ohms to 47k ohms).

 The ESP8266 module

- When accurately measuring, the proper alarm point for the gas detector should be determined after considering the temperature and humidity influence. The detecting concentration scope:

• 100 - 300ppm NH3
• 10ppm - 1000ppm
• Benzene - 10ppm - 300ppm
• Alcohol