Criando gêmeos digitais no Renode: um estudo de caso com microcontrolador STM32L4 e rádio Zigbee AT86RF233

Abstract

The consolidation of cyber-physical systems and Internet of Things (IoT) applications has increased the demand for verification and validation methods that reduce cost, risk, and development time in resource-constrained devices. Although digital twins are often employed at higher abstraction layers (e.g., cloud integration, visualization, and system-level analytics), faithfully reproducing low-level hardware behavior remains a bottleneck for firmware validation on microcontrollers, especially for low-power families that are still underrepresented in simulation platforms. In this context, this work presents an extension of the Renode simulator, an open-source development framework designed to accelerate embedded system and IoT development by enabling emulation of physical hardware, by implementing a new firmware-level digital twin for the STM32L4 family. The proposed platform is instantiated and validated on the STM32L496 microcontroller and simulated with the IEEE 802.15.4 AT86RF233 transceiver. The proposed approach follows incre- mental, test-oriented development, building a complete new platform through .repl descriptions, C# peripheral models, and .resc automation scripts, covering func- tional integration across subsystems. In addition, this work introduces a newly developed power consumption estimator that accumulates energy statistics over the simulation virtual time, selecting typical current profiles according to frequency, vol- tage, and run/sleep operating modes based on device datasheet metrics. Experimental results demonstrate the execution, without modifications, of a production firmware binary (.elf), whose state machine simultaneously exerci- ses initialization, ADC acquisition with DMA transfers, timer-based timing, radio communication, RX/TX windows and acknowledgment handling, and transitions to low-power operation. Instrumentation via a packet hook enabled frame interception and UDP forwarding for external decoding of telemetry, increasing protocol obser- vability and supporting the validation of RX/TX flows in the simulated medium. Within the defined scope, the power estimation was applied only to the STM32L496 microcontroller and did not include the radio module consumption, serving as a proof of concept for reproducible energy analyses during simulation.