These two circuits helps you to using gas sensor module without using Arduino or any other microcontroller.
Parts list:
IC LM3915 or IC LM3914
Gas sensor module (any type such as mq-04 , mq-02 , etc)
Resistor 1K
Potentiometer 10K
LED (10pcs) or LED Bar
Buzzer
Capacitor 22uF
Circuit number 1 :
This circuit gives you the concentration of the gas by using an LED bar. You can use either discrete LED or LED bar.
You don't need any protection resistor for the LEDs , because this IC has constant current LED driver inside.
By disconnecting the VCC (+5V) from pin number 9 of the IC you can switch the IC to Dot mode.
Circuit number 2 :
The second circuit very simple, it just running a buzzer when detect the gas.
Video:
In following video you can see how this circuit works (with explanation):
Parts list:
IC LM3915 or IC LM3914
Gas sensor module (any type such as mq-04 , mq-02 , etc)
Resistor 1K
Potentiometer 10K
LED (10pcs) or LED Bar
Buzzer
Capacitor 22uF
Circuit number 1 :
This circuit gives you the concentration of the gas by using an LED bar. You can use either discrete LED or LED bar.
You don't need any protection resistor for the LEDs , because this IC has constant current LED driver inside.
By disconnecting the VCC (+5V) from pin number 9 of the IC you can switch the IC to Dot mode.
Circuit number 2 :
The second circuit very simple, it just running a buzzer when detect the gas.
Video:
In following video you can see how this circuit works (with explanation):
