From prototype to a product platform the customer owns

How Diadrom built the base unit software for iFish, a medtech measurement system with several detectors, and handed over a platform the customer could own.

A medtech company developing advanced measurement systems brought Diadrom into iFish to build the software for the system’s base unit: the hub that connects several detectors, stores and synchronises their measurements, talks to the user’s PC, tablet or phone, and keeps every part of the system up to date. Diadrom then handed the platform over, and it went to market as part of the customer’s product.

Every instrument is becoming a system

A measuring instrument used to be one device. Today it is more often a system: several sensors, a unit that collects and stores their data, an application on a computer or a phone, and firmware in every part that has to be updated in the field for years. Each part can work on its own and the system can still fail where they meet. In a regulated field like medtech, the system also has to show what it measured, with which software, and that it was verified.

A medtech company with its own measurement technology

The customer develops advanced measurement systems for medtech. iFish was run in its R&D organisation, with the Vice President R&D as sponsor and project manager for the complete system, and a technical contact who worked with Diadrom’s team throughout.

One hub for several detectors

The base unit had to hold the whole system together. It needed to:

• act as a USB hub between several detectors, connected at the same time;
• communicate with PCs, tablets and phones over USB, Bluetooth and WiFi;
• run on batteries;
• store measurement results, and keep the measurements from several detectors in sync;
• update firmware on the base unit and on the detectors.

What made it hard was the system around it: several detectors in parallel, real-time communication, error handling, and traceability for measurement data, logs, waveforms and software versions.

iFish: the base unit and its software

Diadrom took on the base unit software and the system engineering around it. The team broke the customer’s requirements down into verifiable system requirements, reviewed the architecture across hardware, software and integration, and assessed the real-time communication, synchronisation, storage and update chains before designing the software.

The base unit runs Embedded Linux, built with Yocto, with Diadrom’s base unit application on top. Diadrom’s partners designed the hardware. The work ran in sprints with a steering group, design specifications, test plans and requirement traceability, so that every requirement could be followed to the test that verified it.

A team of about six did the work, and handed over everything the customer needed to own it: source code, the software design description, test descriptions, requirement traceability, the Yocto build description and the development environment.

For the engineers in the room

• System: iFish, a medtech measurement system; Diadrom built the base unit software
• Platform: Embedded Linux, built with Yocto; the base unit application on top
• Connectivity: USB hub for several detectors; USB, Bluetooth and WiFi to PCs, tablets and phones
• Functions: Data collection and storage, synchronisation between detectors, battery operation, firmware updates for the base unit and the detectors
• Engineering: Requirements broken down into verifiable system requirements; architecture review across hardware, software and integration
• Verification: Test specifications, software test descriptions and requirement traceability (SWDD, SWTD, SWRT)
• Team and handover: About six people at Diadrom, with partners for the hardware; source, documentation and build environment handed over to the customer

What it changed

The customer got more than working software. It got a platform it could own: the code, the documentation that explains it, the tests that verify it and the environment to build it, handed over so that its own engineers could take the product further. The platform went to market as part of the customer’s product.

“A prototype proves the idea. A product has to keep working through updates, new detectors and new people for years, and the customer has to be able to own it. That is what the handover in iFish was for.”

— Viktor Eliasson, CEO, Diadrom

Advice to peers

Treat the handover as part of the product from the first sprint: write the requirements so they can be verified, trace them to tests, and keep the build reproducible, because the team that maintains the product is rarely the team that built it. Agree early on how requirements that are not yet defined will be settled. The same holds in railway signalling, as in the PREGO case, and in vehicles, as the APC report on software-defined vehicles shows for any long-lived product with software in it.

Details drawn from Diadrom’s project material on iFish. The customer is not named.