sharadsinha

Posts Tagged ‘Testing’

Component Problems with Electronic Systems

In Education, Embedded Systems, Engineering Principles on December 30, 2014 at 9:37 PM

It is not surprising to find component problems with electronic systems. I was working with a Zedboard recently and it would just not boot from the supplied SD card. The serial driver was properly installed but the LED would not light up. The host PC’s operating system did not complain about any driver issues. Some members on the Zedboard forum complained about the micro-USB socket problem on the board. In any case, when working with a development or an evaluation board, it can become difficult to diagnose such issues. I tried different SD cards as well but to no use.  My laptop can recognize the SD card but Windows is unable to format it!

This experience makes me feel that it is relatively easier to simulate a design and test it for functional correctness. It is more frustrating when components on a board stop working and you do not know which one. For my case, the SD card could be corrupt, the SD card reader could be corrupt; according to forums, there may be issues with the serial port driver etc. It is not that it is difficult to diagnose the issue. It is just that you have try to isolate the problem by looking at different possible issues one by one. It wastes a lot of time especially when you expect a dev/eval board to be up and running quickly.

One board can take away so much time. Imagine if you have to do this for 20 such boards which is usually the case when such boards are procured for student laboratory exercises! Can’t there be a better way to know the status of components? Perhaps it is time to investigate this!

Do you read User Guides?

In Design Methodologies, Education, Embedded Systems, Engineering Principles, Research and Development on May 14, 2014 at 6:32 PM

I am a member of LinkedIn and like many of you am also a member of quite a few LinkedIn groups. The good thing about LinkedIn groups is that the discussions remain professional in tone and content. This is why I like them compared to discussions on other social media platforms where they can vary in tone and content from the most professional to the most ridiculous. In a discussion on such a LinkedIn forum meant for engineers, someone admitted that very few engineers or users of tech tools read the user guides. This is not far from reality. I have seen this when I interacted with practicing engineers on a more regular basis than now. I also see it in academic life.

Personally, I find user guides of development boards, software and hardware tools extremely useful. Reading them once gives me enough confidence in extracting the best out of these tools. For instance, user guides of FPGA vendor providers are very helpful and I am more confident about my design after having referred to the user guide at least once though often these guides can be voluminous. I guess the verbosity of these guides is one main reason why people don’t feel like reading them. The other reason, I think, is the propensity of many practicing engineers, graduate students and others to get  their hands dirty as soon as possible. They want to write code, design a circuit, run simulations etc. without getting bored reading these guides. While this enthusiasm to start working is worth appreciation, ignoring the “reading” part leads to problems later on in the product development process, research methods and has the potential to creep into the results. Basically, this haste leaves one vulnerable to questioning at a later stage. Sometimes this can prove very costly as well especially if it is related to product development. Of course one can always talk about pressure for results from managers, supervisors, customers etc.; this is not a very good excuse. Good managers etc. also understand the importance of being abreast with background information.

Is this issue observed more in the engineering industry than say banking or insurance sectors or for that matter safety critical engineering domains? Perhaps. Engineers take great pride in fixing things. They can use patches for software, make new releases, change components or simply replace the product.  However, bankers and insurers cannot do much once money is gone. The fear of losing money is too great to sustain the dislike for reading guides, whitepapers etc. Similarly those involved with safety critical engineering domains are more mindful about liability issues that aversion to poring over thick user guides is probably a non-issue.

One can also argue that  the presentation style of many user guides is quite boring. I agree when you compare with things that provide “instant thrill” thus leading to a desire to know more. User guides do not provide that thrill but writing code, experimenting with a development board etc. does give a lot of thrill to many engineers. Nevertheless, when it comes to getting a job done properly, there is no other choice but to sweat it out! 🙂

A Case For Electrical and Eelectronic Measurement

In Design Methodologies, Education, Embedded Systems on October 23, 2012 at 12:36 AM

Perhaps one of the least emphasized part of university education in electrical, electronics or computer engineering is related to the field of electrical and electronic measurements. Electrical measurements generally involve measuring current, voltage and resistance. In an embedded systems that has sensors, such measurements can play a critical role. The output of these sensors are converted to either current or voltage before further processing in software or hardware. Not only to test such a system but also to design it properly, it is important to understand the basic concepts of measurement like accuracy, repeatability, resolution, instrument error, instrument noise, capacitance of cables, probe resistance, instrument calibration etc. I had my first real experience with some really tough measurements to be done on an OC192 board for a telecommunication application while trying to debug some issues. I must say that while we place a lot of emphasis on software and hardware design issues, it is also important to consider the measurement side of the story in order to test if  the software and the hardware are working properly. Measurement concepts like instrument calibration, sensitivity and timing are very important in a test set-up. Sometimes, we miss out these things resulting in a mismatch between requirements and implementation.  Keithley’s Getting back to the Basics of Electrical Measurements is  good for introduction as well as for refreshing one’s basic knowledge.