Q: IS sensors command from lm-sensos able to find all the internal and external sensor devices? I am not sure about the detected list of sensor explored with sensors command provided by lm-sensors package. 
As the wiki of this package said: 

lm_sensors (Linux monitoring sensors) is a free and open-source application that provides tools and drivers for monitoring temperatures, voltage, and fans.

I am a bit doubt about:


*

*Does it confined / limited to all the internal sensors belongs to a computer or it can also detect external sensors (like proximity sensor, temperature, humidity and so on) connected to a computer?


I have read the manual from man sensors and sensors --help but didn't find the clear explanation.

A: lmsensors is not magical - it can only detect built-in sensors that it learns about from interrogating the hardware. 
"external" add-on sensors on GPIO won't be known to the hardware -- so additional code will be needed to read and interpret that input. Sorry.
