The challenge
Construction and infrastructure projects in the Netherlands are subject to strict regulations on vibration nuisance. Consultancy agencies overseeing construction projects must demonstrate that vibration levels stay within the SBR guidelines. This requires continuous, reliable on-site measurements.
Existing solutions were expensive, heavy, inflexible, or required manual data collection and processing. What was missing was an affordable, real-time measurement system: place the sensors, and immediately monitor from the office.
That was the gap we set out to fill. With a complete platform from the physical sensor to the dashboard where a consultant manages their projects.
Our approach
Everything in-house, from circuit board to browser. Frogwatch was fully designed and developed by Jitter. This means we control every layer of the stack ourselves.
Hardware: Electronics
At the core is an ultra-low-power electronics platform featuring a custom-designed "motherboard" with an STM32 microcontroller, LTE modem, and battery management system. The motherboard connects to a custom sensor PCB with MEMS accelerometers for three-axis vibration measurements. The electronics design is fully optimized for low noise, low power consumption, and years of deployment on construction sites. EMC-resistant design is central — a construction site is no laboratory. The sensor communicates via 4G/LTE with the cloud: place the sensor, power it on, and the data flows.
Mechanical: Custom CNC enclosure
The aluminum enclosure and electronics are fully designed in tandem. The enclosure is inspired by the original Unibody MacBooks: CNC-milled from a solid block of aluminum for maximum strength and rigidity, so the circuit boards fit precisely. The design is optimized for ease of assembly — the number of cables is reduced to just one. Cables are often the weakest point and consume the most time during assembly.
Software and firmware in Rust
Both the sensor firmware and the server-side code are written in Rust. With Rust you get the performance of C but also the higher-level abstractions to build robust, modular software. The firmware runs on an STM32 microcontroller with limited working memory. The memory safety that Rust provides is ideal for an embedded system that must run autonomously for months on location without crashes or memory leaks. The firmware handles accelerometer data acquisition, signal processing, local buffering, and the secure, encrypted transmission of measurement data over the mobile network.
Dashboard: real-time insight
The dashboard is an Angular web application that lets consultancy agencies manage their projects. Per project they see which sensors are active, current vibration levels, historical data, and whether SBR threshold values have been exceeded. Automatic alerts warn when limits are breached, so a consultant doesn't need to monitor continuously. Designed for the daily practice of a structural consultant: clear, fast, and focused on the information that matters.
Cloud & backend
Measurement data arrives at a server backend originally built with Meteor (Node.js) and MongoDB. As the platform grew and performance and reliability requirements increased, we began migrating the backend to Rust. Currently the system runs hybrid: existing functionality and support for V1 Meters in Node.js, new modules in Rust.
This gradual migration is a deliberate choice. We replace components step by step, without disrupting the running platform. Users notice nothing. Comparable to replacing parts of a moving train.
From V1 to V2
Frogwatch wasn't built in one go. The first generation (V1 from 2017) used a different accelerometer and a different architecture with firmware written in C. Based on years of field experience and user feedback, we fundamentally redesigned the platform.
The second generation (V2, released in 2024) features an improved sensor design, a completely rewritten firmware stack (the switch to Rust), improved connectivity, and an expanded dashboard. It's a great example of how powerful iteration is in developing and continuously improving a product. That iteration is possible because we control every layer ourselves.
V1
V2
The result
Frogwatch is deployed on construction sites across the Netherlands and Belgium. Consultancy agencies use the platform for official vibration monitoring in compliance with SBR-A, SBR-B, and SBR-C guidelines. The product has become successful enough to continue as an independent company: its own B.V., its own website, its own commercial identity.
What Jitter delivered
This project shows what Jitter can do as a full-stack electronics partner:
- PCB design — custom sensor hardware, from schematic to production
- Mechanical design — CNC aluminum enclosure
- Embedded firmware — Rust on STM32, built for long-term autonomous deployment
- 4G/LTE communication — TLS-secured data transmission via MQTT over the mobile network, with OTA firmware upgrades
- Cloud & backend — from Meteor/Node.js to a hybrid Rust architecture
- Web application — Angular dashboard for real-time monitoring and project management
- DevOps — monitoring, maintaining, and upgrading the servers
- Product lifecycle — from first prototype through multiple hardware and software generations to a mature platform
- Production & assembly — of Frogwatch equipment
Frogwatch is now an independent company. Visit www.frog.watch for more information about the product.
