SmartSole provides means of recongnizing the pressure points' patterns of the feet in different activities, such as walking, running, skiing, and so on. Equipped with an intelligent foot sole that monitors the pressure of three main points of contact, and a visualization mobile application, it provides an accurate description of the way the foot moves in different scenarios.

Being a solution that tracks patterns in user's feet movement, it has a large variety of applications. On one hand, it can be used by athletes for performance tracking and technique monitoring, helping them to constantly improve. On the other hand, it can be used as a tool to detect issues related to foot motion that lead to other problems (an example would be knee pain caused by poor foot placement and motion). It is designed for a large category of uses, the main goal being to help the user regarding his activities.

The embedded device is one of the two main components of the solution. Its purpose is to collect data from three pressure sensitive sensors carefully placed on the main contact points of the foot, process it accordingly, and then, send it to the mobile application for visualization and statistics. The components used for making the mentioned device are the following:

• ESP32 development board
• 18650 Li-Ion battery charger module
• 18650 Li-Ion battery
• pressure sensitive sensors
• other components

The below image presents the schematic of the embedded device. The ESP32 module acts a the logic unit, taking care of RF communication and data processing. The Li-Ion battery charging module powers the control board via USB, having the possibility to charge the battery as well from another port. It also has an ON/OFF switch giving flexibility of usage. Moving to the sensing portion, we can observe that each sensor is part of a voltage divider, one if its pins being connected to the board 3.3V output and another one to the 10K pull-down resistor and the input pin. In this occasion, each of them act like a potentiometer, changing resistance when pressed.

The mobile application acts as a visualizations tool, for the user to check the measurements in a friendly and easy-to-use manner. We will run our application on a Samsung Galaxy S6 Egde, using Android Nougat (API 24).