IoT-Dorks - credits to @IoT-PTv on github 

Google
        intext : datasheet , configuration , manual , settingup , guide

    filetype : pdf , doc etc
    device** : name of the brand or type of the device like camera,smarthome or anything else
    usage : intext:datasheet filetype:docx device:camera

Shodan
Search keyword
    "internet of things"
    "upnp httpd"
