This thesis has analyzed the use and potential of a cost-effective and energy-efficient Time-of-Flight sensor for acquiring three-dimensional data in domestic environments. The work focused on integrating the VL53L5CX sensor with a generic microcontroller, developing an autonomous system capable of Movement, acquiring and transmitting information without the use of wired connections. The primary goal of this thesis was to develop a system for data acquisition and processing using a Time-of-Flight (ToF) sensor, specifically the VL53L5CX, integrated with an STM32 microcontroller for sensor management and control. The project involved implementing algorithms for data filtering and aggregation and visualizing the results through a dedicated software platform. The solution was tested in various scenarios, with applications robotics, home automation and environmental scanning.
What is the light-weight ToF sensor?
Light-weight ToF sensors like VL53L5CX are designed to be low-cost, small, and low-energy, which have been massively deployed on mobile devices for the purposes like autofocus, obstacle detection, etc. Due to the light-weight electronic design, the depth measured by these sensors has more uncertainty (i.e., in a distribution instead of single depth value) and low spatial resolution (e.g., ≤ 10×10), and thus cannot support applications like 3D reconstruction or SLAM, that require high-fidelity depth.
Let's use the VL53L5CX as an example to explain the sensing principle of the light-weight ToF sensor. For conventional ToF sensors, the output is typically in a resolution higher than 10 thousand pixels and measures the per-pixel distance along the ray from the optical center to the observed surfaces. In contrast, VL53L5CX (denoted as L5) provides multiple depth distributions with an extremely low resolution of 8 × 8 zones, covering 63° diagonal FoV in total. The distribution is originally measured by counting the number of photons returned in each discretized range of time, and then fitted with a Gaussian distribution in order to reduce the broadband load and energy consumption since only mean and variance needs to be transmitted.
Tof sensor application
Resut
The results demonstrate how an affordable sensor (2 to 4 $) can still offer high performance in terms of accuracy and reliability in collecting three-dimensional information. The results obtained demonstrate that for many needs, such as collision prevention and obstacle detection, it is not necessary to use expensive LiDAR sensors, and it is possible to rely on the potential of these low-cost and low-power sensors.
@inproceedings{
title={Development of a 3D measurement system, based on microcontroller and ToF sensor and its integration in domotics},
author={Arash Alghasi},
University={University of Genoa},
year={2025}
}