MTM Case Study: Sphero

“It was too easy. We had our MTM test running in a day. Traditional modular test takes 3 weeks.”

Sphero, a leading manufacturer of robotic toys, deployed MTM in their functional circuit testers (FCTs) for a high-volume product with an aggressive launch schedule. By using MTM-based architecture, Sphero’s manufacturing test team reduced FCT development time by 80% and they were able to replicate dozens of reliable fixtures in just 3 weeks to meet their product launch date.

The Problem

Historically, Sphero’s manufacturing testers used several different instrumentation components inside their fixtures, including expensive external Digital Multimeters (DMM), programmable power supplies and logic controllers. These components are expensive and require several software licenses for separate APIs which are required to control the mixed instruments. These challenges mean that engineers need several weeks to prototype a production test. Further, connecting these instruments to the Device Under Test (DUT) requires a complex series of cables and wire-wrapped pogo pins, adding complication to the tester design. As Sphero’s end product is a toy, cost of test and equipment was always at the forefront of their test design and equipment selection decisions.

Designing and building one tester and making it work is one thing. Making dozens of them quickly and operating reliably is adds to the time and cost challenges.

The Solution

The license-free, unified BrainStem APIs of MTM provided Sphero engineers with a simple tool set to begin their development. The small size and low power of MTM modules allowed Sphero’s test engineers to eliminate the expensive external DMM and power supply components and integrate these measurement functions directly inside their test fixture.

With instrumentation integrated inside the fixture, testers could be made more reliably and accurately. The lightweight and unified BrainStem APIs were easy to start with and Sphero engineers started designing in just a few hours and total test development time went from weeks to days.

The simplified fixture design also reduced complex manual cabling and assembly steps, so Sphero’s tester could be quickly and inexpensively replicated by their fixture assembly partner.

The Results

By shifting their FCT testers to BrainStem/MTM series instrumentation, Sphero yielded:

- 80% reduction in initial test development time

- 70% reduction in time to replicate additional testers

- 60% reduction in instrumentation capital cost