Embedded firmware and connected telemetry software for a rugged handheld sound level meter, combining instant high-contrast acoustic readouts with edge-calculated acoustic indices, local SD card logging, and cloud connectivity.
The Challenge
Acoustic compliance surveys and industrial noise monitoring require high precision without operational complexity. Many sound level meters either offer bare-bones analog displays that lack regulatory data, or bury critical metrics inside convoluted menus that overwhelm field technicians. Furthermore, capturing transient noise spikes while simultaneously computing long-term exposure indices (like statistical percentiles and equivalent sound levels) demands heavy, real-time digital signal processing—often draining battery life and leaving field teams without cloud synchronization for remote compliance reporting.
What We Built
We engineered the complete embedded firmware and companion telemetry interface for an intelligent, handheld Class/Type sound level instrument. Designed around high-precision A-weighted acoustic front-ends, the onboard firmware samples ambient noise continuously, executing edge DSP routines to compute instantaneous sound pressure, Min/Max/Average thresholds, and complex equivalent acoustic metrics ($L_{eq}$, $L_{10}$, $L_{50}$, $L_{90}$). The device features an ultra-responsive, glanceable on-screen display for immediate decisions, while dual-logging architecture writes timestamped raw datasets to an onboard SD card and syncs session summaries to a secure cloud platform.
Key Capabilities
- A-Weighted Edge Acoustic Processing: Continuous real-time DSP pipelines calibrated for A-frequency weighting, standard Fast/Slow time constants, and wide dynamic range capture.
- Instant Statistical Noise Metrics: On-the-fly calculation of Min, Max, Average ($L_{avg}$), Equivalent Continuous Sound Level ($L_{eq}$), and statistical percentiles ($L_{10}$, $L_{50}$, $L_{90}$) directly on the embedded processor.
- Glanceable High-Contrast UI: Clean, high-legibility layout showing live dB(A) numerical readouts, dynamic level-trend bars, and threshold exceedance indicators at a single glance.
- Dual-Tier Data Logging: Microsecond-indexed CSV/binary logging to onboard FAT32 micro-SD cards paired with automated session-based cloud syncing over integrated wireless/cellular backhaul.
- Cloud Telemetry & Audit-Ready Export: Centralized web portal connectivity allowing safety managers to aggregate surveys, track baseline ambient shifts, and generate certified environmental and occupational noise reports.
Outcome
Turned complex acoustic analytics into a durable, grab-and-go handheld tool. Safety officers and acoustic engineers get immediate on-site clarity through a zero-friction screen, backed by enterprise-grade data fidelity and automated cloud records for occupational safety and environmental audits.