in this directory with the flasktest.py file enter:
export FLASK_APP=flasktest.py
flask run --host=0.0.0.0
to test the server:
curl -v --data "pin1=323" 127.0.0.1:5000/data
to monitor the connection: (replace eth0 with your interface, perhaps wlan1)
tcpdump -i eth0 -s 512 -A -n -tt -v tcp port 5000