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Software module notes errors, violations during Bluetooth development efforts

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Teledyne LeCroy, Inc. the worldwide leader in Bluetooth protocol analysis and testing services is pleased to introduce the Bluetooth Protocol Expert System software module, enabling accelerated development of Bluetooth devices and speeding development and troubleshooting of device interoperability in the Internet of Things (IoT).  The Bluetooth Protocol Expert System software module presents errors, warnings, and violations impacting Bluetooth communications.  Those violations are referenced directly back to the relevant sections of the Bluetooth specification, allowing quick identification, understanding and resolution of complex issues.

The proliferation of Bluetooth enabled devices in our interconnected world is staggering, yet promises dramatic improvements to information gathering, comfort or quality of life, productivity, and safety.  To deliver those IoT promises, devices must work well together.  Historically, when Bluetooth issues arose engineers developing, testing, and troubleshooting IoT devices captured a trace and used it to find errors.  The trace, along with their knowledge of the specification, enabled them to seek out the errors and identify issues.  Often they would refer directly back to the specification itself, verifying how the technology should be used.  This process was slowed if the engineer was new to the technology.

Teledyne LeCroy, the leader in Bluetooth protocol analysis, just made testing IoT devices a whole lot easier. With the Bluetooth Protocol Expert System, the referencing is done for the engineer.  This system not only identifies BR/EDR and LE errors, warnings, and violation, it goes one step further – it links those events in the trace directly back to the Bluetooth specification, alleviating the need to memorize the specification or search through it for explanations.  As a result, issues can be resolved faster, even by people not familiar with the specification. The Bluetooth Protocol Expert System makes the Bluetooth novice an expert, and makes the expert’s job easier.

The Bluetooth Protocol Expert System software module ships with an exciting “toolbox” of features including the ability to emulate an A2DP sink device and the ability to generate and inject low energy packets directly into in the 2.4 GHz spectrum.  The A2DP sink functionality dramatically simplifies the troubleshooting of A2DP source devices by providing engineers fine grain control of an emulated A2DP sink device.  The low energy jammer or packet generation functionality provides engineers the means to test devices in a “noisy” environment by generating packets or “noise”, forcing the device under test to accommodate and adjust as it would in the real world.

“We’re really excited about the Protocol Expert System” says David Bean, General Manager of Teledyne LeCroy’s Frontline product group.  “Engineers using it to develop and troubleshoot their Bluetooth devices will enjoy significant time savings.  Not only does it make their job easier, it gives them the tools they need to ensure interoperability and the best out-of-box experience possible.”

The Bluetooth Protocol Expert System software works in tandem with Frontline’s powerful protocol analyzer software.  It is optimized to work with Frontline hardware including the Sodera Wideband Bluetooth Protocol Analyzer and the Sodera LE low energy Bluetooth Protocol Analyzer.

Image gallery: Cool autonomous vehicle tech at TU-Automotive Detroit

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The recently wrapped-up TU-Automotive Detroit conference on autonomous and connected vehicles played host to 150 conference speakers and 3,000 people kicking tires in the 200,000-ft2 exhibition area. In the pages that follow are some of the more interesting technologies we found on display as we roamed the exhibit aisles.

Taking a ride in a robotic vehicle

perrone auto carPerrone Robotics and its current reference vehicle Linc – a 2017 Lincoln MKZ – maneuvered around the parking lot directly across from the show main entrance. Lucky riders got to see Linc perform different maneuvers, run its software on different platforms, and adapt to obstacles. Perrone makes a software platform for robotic vehicles called Max which puts services for different kinds of functions in different layers so they, presumably, don’t interfere with one another.

NEXT PAGE: An electric FireFly

What does an eye diagram or eye pattern on an oscilloscope mean?

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Figure 1: Eye diagrams are useful for determining at a glance the health of a digital signal. As a diagnostic tool, it shows the performance in aggregate, so locating which edge is associated with an artifact is difficult. (Source: Author markup.)

Eye diagrams are a quick, visual means to quickly identify whether there are any signal integrity issues before moving on to more refined analysis. Eye diagrams help with the effective analysis of serial data, and offer both qualitative and quantitative insight regarding the data communications signal path itself and what might be affecting signal integrity.

Circuit designs that get to prototype stage may have been simulated prior to testing a PCB prototype. However, every design gets bench-tested before going on to higher volume production. In developing and interfacing to high speed serial communications such as USB, you will want to use an oscilloscope to troubleshoot and analyze serial data. Viewing eye diagrams can help with finding crosstalk, electromagnetic interference (EMI), signal loss and other phenomena that affect signal integrity. The term “eye” refers to the fact that the pattern on the oscilloscope looks like an eye. The bigger the opening of the “eye,” the better, in terms of signal to noise ratio. The general amount of jitter can be seen in the crossing.

Figure 2: Eye diagram, or eye pattern showing constant 0 and 1 levels and transitions from 0 to 1, 1 to 0, and from 0 to 1 to 0 as well as 1 to 0 to 1. (Source: Wikipedia, credit: Gmoose1.)

An eye diagram is a pattern shown on an oscilloscope that depicts a fuller view of what a digital signal stream looks like from a more holistic viewpoint, one could say. What’s actually happening is that the oscilloscope is receiving, or sampling, a digital signal (a stream of step functions that represent 0s and 1s in varying patterns.) The oscilloscope samples little chunks of the received signal and displays them all, superimposed, on the screen. The result looks like an eye on the oscilloscope screen. The scope accumulates the chunks and displays the cumulative effect of the stream of 0s and 1s (step functions) on the screen. Every bit pattern it captures is superimposed on the oscilloscope’s screen.

The purpose of the eye diagram is to witness at a glance the health of the signal integrity. You can easily see the noise margins of the data signal with an eye diagram. Noise margin refers to the amount by which the signal for 0 or 1 exceeds ideal boundaries but is still within an acceptable range. The unit interval or bit period of an eye diagram is defined by the data clock. As mentioned above, the eye diagram displays all of the values, which are in variable positions due to noise or other factors, that a digital signal takes on during a bit period.  Noise and other factors can make the digital signal deviate from a train of perfect step functions in a stream of 0s and 1s, and this is cumulatively displayed in aggregate in the eye diagram. A closed eye indicates a noisy, unpredictable signal.

Eye diagrams are great for a quick high level diagnostic, but they do not make good diagnostic tools beyond telling you if it looks good…or not. The performance of the digital signal is shown in aggregate, which makes it difficult to diagnose which edge is associated with a specific artifact. Older oscilloscopes show the eye diagram in one color. Modern oscilloscopes help with diagnostics somewhat by at least showing signals in different colors corresponding to frequency and voltage level on a per pixel basis.