From: Joss <Log...@gm...> - 2011-09-15 13:45:17
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Hello Dave, the community, As the I2C communication problems are still occuring I attached an image which shows the hardware connections currently used. The code used still remains the same as can be read throughout this topic. I use the following hardware: Gumstix with an Overo Tobi extension board, a Phillips dual bi-directional bus buffer P82B96 as level-shifter and a Honeywell HMC6343 3-Axis Compass. http://old.nabble.com/file/p32471727/Bildschirmfoto.png The adress byte and an ACK-bit is being sent, as can be seen in the image of the initial post in this topic. But no data byte with the command, what the HMC should do, is being sent. Only the first byte with the adress (0x32 HMC related). The logic analyzer I use is connected to both sides of the level shifter and the outcome in terms of analyzing the SDA and SCL lines is the same for both of 'em... Dave Hylands wrote: > > Hi Joss, > > On Thu, Aug 18, 2011 at 8:54 AM, Joss <Log...@gm...> wrote: >> >> Uh...you are right, Dave. Should be "=" . :D >> I missed that one. >> >> Anyways, my logic analyzer just has shown me the write-message including >> an >> ACK. The read-part is not being transfered. >> Regarding the i2c bus speed: >> I've checked and it is set properly at 100kHz... > > So then you need to check that you have a common ground between the > compass and the gumstix. > > And you should put your logic analyzer on the gumstix side of the > level shifter to make sure that the ack is being seen. > > I'm assuming that you're using a proper bidirectional level shifter > designed for i2c for both SDA and SCL. > > -- > Dave Hylands > Shuswap, BC, Canada > http://www.davehylands.com > > ------------------------------------------------------------------------------ > Get a FREE DOWNLOAD! and learn more about uberSVN rich system, > user administration capabilities and model configuration. Take > the hassle out of deploying and managing Subversion and the > tools developers use with it. http://p.sf.net/sfu/wandisco-d2d-2 > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > -- View this message in context: http://old.nabble.com/I2C-Communication-Problems-tp32271588p32471727.html Sent from the Gumstix mailing list archive at Nabble.com. |