I've used Mini and ESP8266 to upload single data to ThingSpeak successfully. Now, I would like to upload data files to platform like dropbox, goole drives or goolge docs. But I don't know whether these using these two only could do the job. If yes, how? I know Arduino Yun and an WiFi shield could do it but power and cost are my primary concern so I wouldn't consider.
Any pointers? Thank you.