Gas sensor signal to a Arduino Mega 2560 microcontroller?

Hi all!

I am totally new to the use of microcontrollers and I have a project that I am working on where I am required to use one. The basic idea is to have a Natural Gas MQ-5 sensor detect changes in gas levels and send a signal to the Arduino, my question is since te gas sensor will detect an analog signal and the microcontroller can understand digital, how do I get the arduino to understand that signal? Do I need to use an a/d converter to change from analog to digital? Or does the microcontroller have a built in function that will do it?

Thank you,
Yesenia

PS I am using the Arduino Mega 2560 microcontroller

The basic idea is to have a Natural Gas MQ-5 sensor detect changes in gas levels and send a signal to the Arduino

That's not the way that sensor works. You use it to read a value from an analog pin that corresponds to the amount of gas detected.

Or does the microcontroller have a built in function that will do it?

It has a built in ADC and function (analogRead()) for reading it.

Note that those sensors are not as easy to use as one might hope or expect. First they require a heater current of around 160 ma @5vdc. Second they have no internal reference so they really need to be 'calibrated' with gas samples of known percentage of the gas being measured. Also over time the heater emission falls off requiring recalibration, especially if used in safety sensitive applications. At the refinery I worked at we had to have them calibrated monthly with approved sample gas.

Lefty