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Topic: MQ-7 module how to use? (Read 27 times) previous topic - next topic

l1232531

Hi
I buy a MQ-7 module to make a CO sensor system
I have read the MQ-7 datasheet
The datasheet say MQ-7 need 60s for 5V supply to heat
and 90s for 1.4V supply to read the CO signal
But I use is module
There have four pin
Vcc,GND,DOUT,AOUT
I do this:
(MQ-7)          (Arduino)
GND---------->GND
AOUT--------->A1 pin
I don't know Vcc that where it is connect
Connect 5V or PWM and use program to control the MQ-7's power supply
Can anyone who have used the MQ-7 module tell me how can I use this module?
My MQ-7 module is this one
http://ecx.images-amazon.com/images/I/41JormPfFpL.jpg

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