Read ad values from sensor, and calculate the respective ppm value of respective gas .

Dependencies:   MQ4 mbed

Revision:
0:9f3c885e7d4e
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Tue Jul 17 04:40:44 2018 +0000
@@ -0,0 +1,1 @@
+https://os.mbed.com/users/mbed_official/code/mbed/builds/a7c7b631e539
\ No newline at end of file