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arXiv · 2510.20038

NanoHydra: Energy-Efficient Time-Series Classification at the Edge

Cristian Cioflan·Jose Fonseca·Xiaying Wang·Luca Benini
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Abstract

Time series classification (TSC) on extreme edge devices represents a stepping stone towards intelligent sensor nodes that preserve user privacy and offer real-time predictions. Resource-constrained devices require efficient TinyML algorithms that prolong the device lifetime of battery-operated devices without compromising the classification accuracy. We introduce NanoHydra, a TinyML TSC methodology relying on lightweight binary random convolutional kernels to extract meaningful features from data streams. We demonstrate our system on the ultra-low-power GAP9 microcontroller, exploiting its eight-core cluster for the parallel execution of computationally intensive tasks. We achieve a classification accuracy of up to 94.47% on ECG5000 dataset, comparable with state-of-the-art works. Our efficient NanoHydra requires only 0.33 ms to accurately classify a 1-second long ECG signal. With a modest energy consumption of 7.69 uJ per inference, 18x more efficient than the state-of-the-art, NanoHydra is suitable for smart wearable devices, enabling a device lifetime of over four years.

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Cristian Cioflan, Jose Fonseca, Xiaying Wang, Luca Benini. 2025-10-22. NanoHydra: Energy-Efficient Time-Series Classification at the Edge. https://arxiv.org/abs/2510.20038

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