I2C communication

You might also want to have a look at Bus Pirate:

Hans.

r

dvark,

Aardvark is "Linux Compatible".

"Wireshark is a network protocol analyzer" eg. Ethernet.

RK

No, you not. You, my friend, are very, very stupid.

Emulate I2C by bit banging through PC LPT port. Emulation of master is trivial, slave is little bit more tricky.

Idiot

First and foremost: I2C is simple thing and there is absolutely no need to analyse it (unless you do reverse engineering).

VLV

1) Bit banging an Ic2 Slave on a PC Printer port is a bit more than tricky. It is tricky bit banging a slave on a micro 2)I2C is simple if you are talking to an EEPROM. On a busy bus an Analyzer can be quite handy.

MCC makes them also MCC-US.com

No problem. You only have to load old good DOS.

Done quite complicated systems with I2C shared in multitask OS. Never had a need to analyse the bus. There is no point to do that: if you have control of the master, you know what is going on.

VLV

Which is fine until you have a multi master bus, or you are not entirely sure your master is working as intended - e.g. it is being bit-banged. Debugging and analysis tools are completely pointless if you know exactly what is going on - you have no need even for a voltmeter if you are able to compute accurately what the voltage at a given point will be in a given situation. However it often helps to be able to measure things since your assumptions about a system are not always correct. Sure, I don't have an I2C analyser here and I've always managed to get by without one, but that doesn't mean I seen times when one would have been useful.

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Andrew Smallshaw
andrews@sdf.lonestar.org

dvark,

The Beagle products are REALLY good. I've used them on SPI and I2C to debug weird problems and to reverse-engineer protocols. They can capture everything, trigger on certain events, ... ... ...

There are I2C interpreters included with some USB logic analyzers. The one that I've been using for ages (maybe someday they'll even come out with a new model!) is over at

The application software can be loaded and run in demo mode without the LA pod itself, so you can get a feel for how it's set up.

And I do agree with you. Bringing up a new peripheral on a new uC talking to a new external device does often leave one wondering whether all of the right registers have been touched in just the right way, whether the timing is happy, and so on. It's comforting to be able to just look at what is happening ...

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Rich Webb     Norfolk, VA

That great attention paid to multi master I2C thing always surprised me. Had anyone ever seen a system with multiple masters on I2C in reality?

If one can't implement such a trivial thing like I2C master bit banging so to be entirely confident in it, he is not fit for embedded.

I verify the code with LEDs, scope and control printouts; never had any need for fancy debug tools. Best debug is not making techical mistakes at first time.

Vladimir Vassilevsky DSP and Mixed Signal Design Consultant

Yeah, you never had something NOT work as expected. YOU never had to learn how to do anything, it just comes to you. Blah, blah, blah. We get it, you are the Master and the rest of us are not worthy, now shut the f*ck up. Didn't your mother ever tell you that if you don't have anything nice to say, don't say anything at all.

See above, oh great one....

I love to see you puffed up peacocks strutting for the sake of doing it. What are you 12 years old?

Yes SMBus Batteries are MultiMaster.

Try Coding the master and slaves at the same time. There is only so much you can see on a DSO.

Normal I agree. But I had the monitor, ( from a former job where there was finger pointing) I used it, it saved me time.