A simple unauthenticated telnet server for exporting CSV data, Arduino+ESP8266
The quickest path between a mass of sensor readings and a spreadsheet might be a CSV file, and this simple telnet server running on an Arduino + ESP8266 dumps data formatted as CSV.
It runs on port 2222, and you could get a foo.csv file by running something like telnet 192.168.0.235 2222 > foo.csv on your command prompt.
I explained it all (but only in portuguese) here: http://br-arduino.org/2015/11/servidor-esp8266-telnet-csv.html