An Update on Toyota and Unintended Acceleration

In early 2011, I wrote a couple of blog posts (here and here) as well as a later article (here) describing my initial thoughts on skimming NASA’s official report on its analysis of Toyota’s electronic throttle control system. Half a year later, I was contacted and retained by attorneys for numerous parties involved in suing Toyota for personal injuries and […]

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RTOS, TDD and the “O” in the S-O-L-I-D rules

In Chapter 11 of the “Test-Driven Development for Embedded C” book, James Grenning discusses the S-O-L-I-D rules for effective software design. These rules have been compiled by Robert C. Martin and are intended to make a software system easier to develop, maintain, and extend over time. The acronym SOLID stands for the following five principles: S: […]

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Trends in Embedded Software Design

In many ways, the story of my career as an embedded software developer is intertwined with the history of the magazine Embedded Systems Design. When it was launched in 1988, under the original title Embedded Systems Programming (ESP), I was finishing high school. Like the vast majority of people at that time, I had never heard the […]

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Is an RTOS really the best way to design embedded systems?

Recently I’ve been involved in a discussion on the LinkedIn Real-Time Embedded Engineering group, which I started with the question “Is an RTOS really the best way to design embedded systems?“. The discussion, which has swollen to way over 600 comments by now, has sometimes low signal to noise ratio, but I believe it is still interesting. […]

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Embedded Software Training in a Box

I am beaming with pride. I think we have finally achieved the holy grail of firmware training: Embedded Software Training in a Box. Priced at just $599, the kit includes Everything-You-Need-to-Know-to-Develop-Quality-Reliable-Firmware-in-C, including software for real-time safety-critical systems such as medical devices. In many ways, this product is the culmination of about the last fifteen years of […]

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What NHTSA/NASA Didn’t Consider re: Toyota’s Firmware

In a blog post yesterday (Unintended Acceleration and Other Embedded Software Bugs), I wrote extensively on the report from NASA’s technical team regarding their analysis of the embedded software in Toyota’s ETCS-i system. My overall point was that it is hard to judge the quality of their analysis (and thereby the overall conclusion that the […]

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Unintended Acceleration and Other Embedded Software Bugs

Last month, NHTSA and the NASA Engineering and Safety Center (NESC) published reports of their joint investigation into the causes of unintended acceleration in Toyota vehicles. NASA’s multi-disciplinary NESC technical team was asked, by Congress, to assist NHTSA by performing a review of Toyota’s electronic throttle control and the associated embedded software. In carefully worded concluding statement, NASA stated […]

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Embedded Software Boot Camp in a Box

Whether you are new to embedded software development in C or looking for ways to improve your skills, the Embedded Software Boot Camp in a Box will provide you the hands-on education you need. Exercises are based around an ARM processor board (shown below), the MicroC/OS-II real-time operating system, and the IAR Embedded Workbench compiler/debugger, all of which are included in […]

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Firmware-Specific Bug #10: Jitter

Some real-time systems demand not only that a set of deadlines be always met but also that additional timing constraints be observed in the process. Such as managing jitter. An example of jitter is shown in Figure 1. Here a variable amount of work (blue boxes) must be completed before every 10 ms deadline. As […]

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Firmware-Specific Bug #9: Incorrect Priority Assignment

Get your priorities straight! Or suffer the consequence of missed deadlines. Of course, I’m talking here about the relative priorities of your real-time tasks and interrupt service routines. In my travels around the embedded design community, I’ve learned that most real-time systems are designed with ad hoc priorities. Unfortunately, mis-prioritized systems often “appear” to work […]

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