Arduino LM35 + MQ2
Intro: Arduino LM35 + MQ2
In this project i want a device that uses bolt MQ2 and LM35 for a basic alert system
STEP 1: What We Need?
1. First we need an arduino microcontroller
2. LM35 temperature sensor
3. MQ2 smoke and gas sensor
4. We need 6 1K ohm resistors
5. 5 Leds
6. Some jumper wires
7. 1 Breadbord
8. 1 Buzzer
STEP 2: Lets Hook Up LM35 and Its Leds
First connect LM35 and leds just like in the picture and then connect middle leg of LM35 to arduinos analog pin 0 and right leg to + line and left leg to - line and connect blue leds + output to pin 13 and - input to - line with 1K resistor yellow leds output pin 12 and - input to - line with 1K resistor red leds output to pin 11 and - input to - line with 1K resistor and that is it
STEP 3: Lets Hook Up MQ2 and Its Leds and Buzzer
First connect everything just like in the picture connect right leg of the sensor to analog pin 1 and vcc to + and gnd to - and connect buzzers - to - with 1K resistor and + to pin 8 and blue leds - to - with 1K resistor and + to pin 9 and red leds - to - with 1K resistor and + to pin 10 and thats it
STEP 4: Code
Sorry but I couldnt write it to here but you can write it from the video and from the pictures
STEP 5: Video
Hope you can make it and use it
13 Comments
Maxx2017 3 years ago
Mon e-mail est edmondmamita@gmail.com
liderelektronikkonya 3 years ago
DenizG1 3 years ago
sriutpalnath 4 years ago
Hoping that you will be sharing the code.
DenizG1 4 years ago
sriutpalnath 4 years ago
Thanks for helping
michaelc702 6 years ago
DenizG1 6 years ago
the_3d6 7 years ago
This circuit and code won't produce proper readings from MQ type sensors - they require heating/cooling cycles for proper operation. Check my instructable, I've described theory and provided code and schematics: https://www.instructables.com/id/Arduino-CO-Monitor-Using-MQ-7-Sensor/
DenizG1 7 years ago
it should work just fine
the_3d6 7 years ago
Have you tried to measure samples with known concentrations and check if received values are correct?
DenizG1 7 years ago
yep they are correct but sometimes sensor stucks and i have to restart it and it works fine as usual after that. But i dont know why it does that maybe because of cheap arduino or the cheap sensor.
the_3d6 7 years ago
What do you mean by "stucks"? Provides the same value over time, not responding to what is happening, or arduino program isn't updating values? Is it correlated with high concentrations measurements or with arduino cable motion?