Testing your Hardware

9 posts
by nabberuk » Sat Jun 30, 2012 10:31 pm
I'm very new to the hardware side but i've read on various posts that a logic analyser helps with diagnosing communication issues.

I'm a little unsure on the sort i'd need for a beginner, would something like the following be ok?

http://www.hobbytronics.co.uk/test-equi ... ogic-2-pro

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by nabberuk » Sun Jul 01, 2012 8:51 am
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by RaTTuS » Sun Jul 01, 2012 9:02 am
what seems to be the problem?
http://www.catb.org/esr/faqs/smart-questions.html <- ask smart Questions
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by nabberuk » Sun Jul 01, 2012 12:41 pm
I haven't got any issues, I'm only just starting out with electronics and was wondering what the best way to diagnose issues.
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by Gert van Loo » Sun Jul 01, 2012 10:51 pm
It is not possible to give an answer to that question.
Compare it to somebody asking, "How do I work on my car".
There is a whole range of tools and unless you know what you
need to work on, you can't give an answer.

The tool you link to will allow you to debug digital signal, but you may have an analogue problem.

I am an electronics engineer and regularly have to debug circuits.
95% of the time I find the problem using a £5 multimeter.
About 4% is done with a digital storage scope.
The other 1% is all kind of tools like logic analyzer, frequency counter,
accurate (6 digit) multimeter, Pulse generator etc.
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by morphy_richards » Tue Jul 03, 2012 6:44 am
You might look at getting an Arduino. You can use one to make a version of most of the kinds of test equipment you are likely to need. You can configure one as a simple multimeter. (You can use it to work out potential difference and / or current, and using that you can calculate resistance)
You can make an oscilloscope with it and you can make a logic analyser, frequency counter etc. etc.
http://www.practicalarduino.com/project ... c-analyzer

Obviously these wouldn’t be as good as any of the real approaches, like an actual oscilloscope, but for beginners electronics projects I think it would be more than sufficient.
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by morphy_richards » Tue Jul 03, 2012 8:19 am
morphy_richards wrote:... or current...

Although you would need to add a current transformer / Current sensor or include a shunt resistor to achieve this as the analogue inputs on the arduino measure voltage.
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by wpns » Wed Sep 05, 2012 12:25 pm
While that logic analyzer (or any number of equivalent USB-based logic analyzers) would certainly work, and probably be a good teacher resource for demonstrating what SPI and I2C are, most folks don't really _need_ something like that.

Running the tutorials, connecting the devices, and seeing what they do is pretty straightforward, if it doesn't work it's more likely to be improper wiring or coding problems than it is SPI protocol communications issues.

But, it's cheap enough and useful enough that it's probably worthwhile if you _want_ it!
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by jasonclark » Wed Sep 05, 2012 12:59 pm
I've been using;

This is more expensive, but works for me. The link you posted also looked fine.

I've not done any SPI/I2C work on the PI yet, I'm having enough fun in my day job..

But, if you're into hardware control (sensors/displays etc) SPI or I2C is the way to go.
These logic analysers won't replace an oscilisope, so noise/reflections will be far harder to detect - but short cables and sensilble speeds should be fine.

There are so many devices using SPI and I2C, its a great way of expanding the capabilities of the PI.

If you simply just want to connect LED and Switches to the PI, you'll only really need a Multimeter (DVM).
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