15-Year-Old Smartphones Turned Into Compact Servers – The system effectively handles image recognition and project monitoring tasks.
A research team from the University of Tartu has transformed old smartphones into efficient computing nodes. Using 15-year-old Google Nexus devices that cost only $9 each, they built compact data processing clusters that outperform the popular Raspberry Pi in terms of performance.
Led by engineer Huber Flores, the team modified the outdated phones by removing their batteries, connecting them to external power sources, and installing a lightweight Linux-based system, PostmarketOS. The researchers then combined four phones into a cluster—one acting as the “master” and three as “workers.”
This improvised “pocket data center” handles tasks such as image recognition and even website hosting. The project addresses two key challenges: repurposing electronic waste (as over 5.3 billion smartphones are discarded annually) and offering a low-cost alternative to conventional servers.
According to Flores, smartphones are ideal for energy-efficient computing. They generate less heat and are highly optimized for performance.
The system has already been tested in real-world conditions, including:
Underwater fish monitoring off Madeira’s coast (at 25 meters depth);
Analysis of passenger flow at bus stops;
Real-time processing of drone data.
Modern smartphones are more difficult to repurpose due to sealed housings, glued components, and closed architectures. The researchers advocate for more sustainable electronics design, making devices easier to repair and reuse.
“Sustainable development means not only planning for the future but also creatively rethinking what we already have,” said project member Ulrich Norbisrath.