COMMUNICATION ARCHITECTURES FOR CLOUD-INTEGRATED SPECTROMETRIC LABORATORIES: ESP-NOW VS MQTT
Andriy Krupych, Pavlo Levush · Electronics and Information Technologies · 2026
Background. Cloud-integrated spectrometric laboratories face communication challenges in achieving real-time data access and analysis. This study compares two wireless protocols, MQTT (Message Queuing Telemetry Transport) and ESP-NOW (Espressif NOW), for LED control in such environments. MQTT offers lightweight, bandwidth-efficient, publish-subscribe messaging [1–3], while ESP-NOW provides energy-efficient direct communication without a Wi-Fi router. The objective is to evaluate their performance and suitability. Materials and Methods. An experimental setup involved a StellarNet spectrometer, LED light sources, and ESP32 microcontrollers. Two architectures were tested: 1) direct MQTT Communication, where each ESP32 connected directly via Wi-Fi to an MQTT broker; and 2) an edge device with ESP-NOW relay, using an edge ESP32 for MQTT/Wi-Fi communication, then relaying commands via ESP-NOW to other ESP32s. Response times for LED control were measured over 100 cycles, and data were analyzed using descriptive statistics and an independent samples t-test. Results and Discussion. Direct MQTT Communication exhibited significantly lower latency (median ~60 ms) and tighter distribution compared to the Edge Device with ESP-NOW Relay (median ~170 ms). A t-test confirmed a statistically significant difference (t=-46.28), with MQTT demonstrating faster response times. However, the ESP-NOW relay system offers architectural advantages: reduced Wi-Fi dependency for individual nodes, enhanced deployment flexibility in areas with poor Wi-Fi coverage, improved scalability [4], and energy efficiency, making its higher latency a practical trade-off for large-scale laboratory integration. Conclusion. Direct MQTT Communication provides superior low-latency performance. However, the edge device with ESP-NOW relay, despite higher latency, is a highly acceptable solution due to its flexibility, scalability, and reduced Wi-Fi dependency for distributed spectrometric laboratories. This highlights a critical trade-off between absolute speed and architectural benefits for robust, smart, cloud-enabled analytical laboratories. Keywords : MQTT, ESP-NOW, spectrometric laboratory, Internet of Things, latency, embedded systems hardware