• IOT

A Lora ESP32 TTGO module (the “sender”) is connected to an ultrasound sensor are positioned in the parking slot, and transmits the distance between the wall and any obstacle. 

See the sensor in the transparent plastic box, connected to a 5V power supply and "looking" at the bike

An early version used the ESP32 touch detection native capability (using a wire connected to the parking door knob, it is possible to detect when someone touch the knob).

A second LORA module(the “receiver”) gets the data and transmits it to the cloud.

• Cloud

A very simple PHP pages gets the data from the receiver and puts the data into a simple text file.

Another PHP page get the data from the text file, and displays the icon corresponding to the situation (“empty” “car” or “motorbike”). 

viewstate.php web page displayeddisplayed if nothing is in the parking

viewstate.php web page displayed if a motorbike is detected (the number is the distance in centimeters between the sensor and the obstacle).

Other functionalities could be easily added (such as sending a email whenever the car or the motorbikes arrives).

• Mobile

A simple URL widget is added to the phone’s front page : clicking on the widget opens a navigator showing the state of the parking slot

The icon after the "Maps" application links to the "viewstate.php" page

The project proved incredibly easy to setup.

  - Limited soldering need (to connect the ultrasound sensor to the TTGO module, see instructions in the "hardware" section

  - Simple components (even if the project involves both IOT, web and connectivity parts, each of them are very simple). This simplicity comes at the price of security, but is it very easy to harden it (see next section).

a) Adding a “subscription web page” allowing a user to enter his/her email address and to get an email warning whenever the parking slot state changes

b) Adding security layers (HTTPS / encryption of the send <-> receiver communication / password on the webpage)