I2C communication
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From: rc_rcf on 19 Apr 2010 21:46 Hi, I am new to I2C bus. I need your help in letting me know how i can monitor data through a I2C Data bus? I found a few products online like AArdvark, Beagle I2C protocol analyzer. I need product tht is Linux compatible. Moreover, i also need it to monitor as well as allow me to inject some data(sniffing). If you know of any such products please let me know. Could i use aardvark and wireshark in order to fulfil my requiremnts? Will wireshark capture I2C data and help me inject data through it as well??If so any specific plugin required for wireshark? what product will allow me to monitor I2C data as well as inject some data(sniffing)? --------------------------------------- Posted through http://www.EmbeddedRelated.com
From: Neil on 21 Apr 2010 01:17 On 4/20/2010 1:38 PM, Vladimir Vassilevsky wrote: > > > rc_rcf wrote: > >> Hi, I am new to I2C bus. > > No, you not. You, my friend, are very, very stupid. > >> I need your help in letting me know how i can monitor >> data through a I2C Data bus? I found a few products online like AArdvark, >> Beagle I2C protocol analyzer. I need product tht is Linux compatible. > > Emulate I2C by bit banging through PC LPT port. Emulation of master is > trivial, slave is little bit more tricky. > >> Moreover, i also need it to monitor as well as allow me to inject some >> data(sniffing). If you know of any such products please let me know. >> Could i use aardvark and wireshark in order to fulfil my requiremnts? >> Will wireshark capture I2C data and help me inject data through it as >> well??If so any specific plugin required for wireshark? > > Idiot > >> what product will allow me to monitor I2C data as well as inject some >> data(sniffing)? > > 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
From: Andrew Smallshaw on 22 Apr 2010 10:01 On 2010-04-21, Vladimir Vassilevsky <nospam(a)nowhere.com> wrote: > > Neil wrote: > >> 2)I2C is simple if you are talking to an EEPROM. On a busy bus an >> Analyzer can be quite handy. > > 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. 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. -- Andrew Smallshaw andrews(a)sdf.lonestar.org
From: larwe on 22 Apr 2010 10:24 On Apr 19, 9:46 pm, "rc_rcf" <bhumika.nayak(a)n_o_s_p_a_m.gmail.com> wrote: > data through a I2C Data bus? I found a few products online like AArdvark, > Beagle I2C protocol analyzer. I need product tht is Linux compatible. > Moreover, i also need it to monitor as well as allow me to inject some > data(sniffing). If you know of any such products please let me know. 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, ... ... ...
From: Rich Webb on 22 Apr 2010 10:28
On Thu, 22 Apr 2010 14:01:01 +0000 (UTC), Andrew Smallshaw <andrews(a)sdf.lonestar.org> wrote: >On 2010-04-21, Vladimir Vassilevsky <nospam(a)nowhere.com> wrote: >> >> Neil wrote: >> >>> 2)I2C is simple if you are talking to an EEPROM. On a busy bus an >>> Analyzer can be quite handy. >> >> 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. > >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. 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 http://www.pctestinstruments.com/. 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 ... -- Rich Webb Norfolk, VA |