Hardware hacking: Signal tracing

I'm trying to get into hardware hacking as a hobby.  I'm trying to find some good information on the reverse engineering bit.  Does anyone have any good directions or sources of information?  Primarily I'm concerned with signal tracing.  How can I track what bytes are sent accross a line?

I'm wanting to solder some wires into a circuit  and attach to a db9 connector that I can send some signals across to simulate what the button push does.  I'm hacking my sprinkler system.  Just having fun while voiding my warranty.

Thanks
phuff34Asked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

babylonfiveCommented:
You should try a low-cost 'logic analyzer'. This is a tool similar to a oscilloscope, except that it captures the signal levels in a digital domain (active or inactive, depending upon voltage) and displays them with other associated signals.

This type of device in the low-cost department (expensive ones start at $25000+) can either be standalone or operate over USB with a computer.

I'll look up some links and post them in the next few hours for you. Such a tool is very helpful.
Here's an example until I can get more: http://cgi.ebay.com/PC-USB-Oscilloscope-Logic-analyzer-of-UART-SPI-I2C_W0QQitemZ120100014839QQcategoryZ104247QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


david
0
phuff34Author Commented:
Great thanks!  I look forward to the links.  Does it matter if the circuit board is analog or digital?  Or would I need to get a converter if it is analog?

Thanks.
0
babylonfiveCommented:
Yes, of course it would matter.   8 )

If you are banging around with digital stuff, like signals to your DB-9 to your computer or some sort of controller or logic, you need the analyzer part,.. if you are looking at analog you need more of an oscilloscope, which shows actual analog levels over time.

If necessary you can even just use a voltmeter (digital ones are cheap and plentiful) to tell you the voltage or level NOW. The other tools I've mentioned show you those signal levels changing over a period of time, which is much easier to use.

Note that the link i gave you is for a device that acts as a O-scope and an analyzer together.

David
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
fullandbyCommented:
Here is a site where you can get "pinout" information. Also there is plenty of this stuff out there for hobbyists, just google away and you will find plenty.

http://pinouts.ru/
0
babylonfiveCommented:
Thanks for the points!
I hope you make a lot of good progress. Fullandby is right, and that is a great site for pin-outs. You can also use the part number at most manufacturers sites and the pin-outs can be sometimes found in their data sheet.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Programming

From novice to tech pro — start learning today.