From: <jb...@sp...> - 2006-12-11 19:31:51
|
Hi I am currently working on a small toy helicopter (Draganflyer), on this we have put a gumstix/robostix pack. We have some sensor data on the on the Robostix, and from a ultra sonic range finder (SRF08), that we need to relay to the gumstix in the fastest manner possible. All our UART connections are used, so the I2C connection is the only one left. I have made it work with 100 kHz clock, but I would like to run 400 kHz. I have checked that all the devices should be able to handle the 400 kHz clock. In the setup the Gumstix is the Master. I am currently running the 2.6.18gum Linux kernel, and is loading the modules: i2c_core, i2c_dev, and i2c_pxa to enable the i2c communication. I have searched the web but can not find anything on how to set the 400 kHz SCL. Can anybody guide me to what to do, I assume that I should mingle with the I2c driver in the Linux kernel? \Jakob Bj=F8rn |
From: Chris D. <cg...@co...> - 2006-12-11 20:19:43
|
On 12/11/06, Jakob Bj=F8rn <jb...@sp...> wrote: > I am currently working on a small toy helicopter (Draganflyer), on > this we have put a gumstix/robostix pack. We have some sensor data on > the on the Robostix, and from a ultra sonic range finder (SRF08), that > we need to relay to the gumstix in the fastest manner possible. All > our UART connections are used, so the I2C connection is the only one > left. > > I have made it work with 100 kHz clock, but I would like to run 400 > kHz. I have checked that all the devices should be able to handle the > 400 kHz clock. In the setup the Gumstix is the Master. Jakob, The SRF08, in its default configuration, takes 65 milliseconds to complete a ranging operation. Are you sure you really need the reduction in data transfer latency you'll get by going to a 400kHz clock? The delay imposed by the sensor itself is much larger. best, -chris |
From: Jesse W. <jes...@gm...> - 2006-12-12 00:38:10
|
There could be more than one i2c device. Such as an accelerometer, compass and gyro... I kinda wish I knew the answer to the 100khrz to 400khrz problem aswell. On 12/11/06, Chris Danis <cg...@co...> wrote: > > On 12/11/06, Jakob Bj=F8rn <jb...@sp...> wrote: > > I am currently working on a small toy helicopter (Draganflyer), on > > this we have put a gumstix/robostix pack. We have some sensor data on > > the on the Robostix, and from a ultra sonic range finder (SRF08), that > > we need to relay to the gumstix in the fastest manner possible. All > > our UART connections are used, so the I2C connection is the only one > > left. > > > > I have made it work with 100 kHz clock, but I would like to run 400 > > kHz. I have checked that all the devices should be able to handle the > > 400 kHz clock. In the setup the Gumstix is the Master. > > Jakob, > > The SRF08, in its default configuration, takes 65 milliseconds to > complete a ranging operation. Are you sure you really need the > reduction in data transfer latency you'll get by going to a 400kHz > clock? The delay imposed by the sensor itself is much larger. > > best, > -chris > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share > your > opinions on IT & business topics through brief surveys - and earn cash > http://www.techsay.com/default.php?page=3Djoin.php&p=3Dsourceforge&CID=3D= DEVDEV > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > --=20 :wq |
From: Andrei R. <ar...@ya...> - 2006-12-12 02:20:46
|
Try this: edit /include/asm-arm/arch-pxa/i2c.h Make sure that #define I2C_ICR_INIT sets bit (1<<15) Then recompile kernel. --- Jesse Welling <jes...@gm...> wrote: > There could be more than one i2c device. > Such as an accelerometer, compass and gyro... > I kinda wish I knew the answer to the 100khrz to > 400khrz problem aswell. |
From: Andrei R. <ar...@ya...> - 2006-12-12 03:01:10
|
Even simpler, no recompilation: pxaregs ICR_FM 1 --- Andrei Rylin <ar...@ya...> wrote: > Try this: > edit > /include/asm-arm/arch-pxa/i2c.h > Make sure that > #define I2C_ICR_INIT > sets bit (1<<15) > Then recompile kernel. > > --- Jesse Welling <jes...@gm...> wrote: > > > There could be more than one i2c device. > > Such as an accelerometer, compass and gyro... > > I kinda wish I knew the answer to the 100khrz to > > 400khrz problem aswell. > > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get > the chance to share your > opinions on IT & business topics through brief > surveys - and earn cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > |
From: Dave H. <dhy...@gm...> - 2006-12-12 05:38:41
|
On 12/11/06, Andrei Rylin <ar...@ya...> wrote: > Even simpler, no recompilation: > > pxaregs ICR_FM 1 I was going to point off to this thread from the archives, which essentially says the same thing: http://thread.gmane.org/gmane.linux.distributions.gumstix.general/12060/focus=12066 -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: <jb...@sp...> - 2006-12-12 11:37:15
|
Hi I have just now detected a clock speed of 333khz. I followed the suggestion from Andrei Rylin with the recompiling. It worked in the first try, so I have not tryed the other suggestions yet. Tanks for the quick responses. \Jakob Bj=F8rn On 12/12/06, Dave Hylands <dhy...@gm...> wrote: > On 12/11/06, Andrei Rylin <ar...@ya...> wrote: > > Even simpler, no recompilation: > > > > pxaregs ICR_FM 1 > > I was going to point off to this thread from the archives, which > essentially says the same thing: > http://thread.gmane.org/gmane.linux.distributions.gumstix.general/12060/f= ocus=3D12066 > > -- > Dave Hylands > Vancouver, BC, Canada > http://www.DaveHylands.com/ > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share y= our > opinions on IT & business topics through brief surveys - and earn cash > http://www.techsay.com/default.php?page=3Djoin.php&p=3Dsourceforge&CID=3D= DEVDEV > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > --=20 Jakob Bj=F8rn Fyensgade 18, 3.TH 9000 Aalborg Tlf: 29247429 |
From: <tat...@ya...> - 2006-12-12 00:44:18
|
Hi Chris. I'm in the same problem with Jakob. I store the date which is converted by AD converter in robostix.That size is 128×3 Byte. And then send it to gumstix. But compared to the time which is cost to process the data in gumstix, the time which is cost to transfer data is very unaccessable. So if you know the way to change I2C to 400 kHz clock mode, Please teach us. Chris Danis <cg...@co...> wrote: On 12/11/06, Jakob Bj娼フrn wrote: > I am currently working on a small toy helicopter (Draganflyer), on > this we have put a gumstix/robostix pack. We have some sensor data on > the on the Robostix, and from a ultra sonic range finder (SRF08), that > we need to relay to the gumstix in the fastest manner possible. All > our UART connections are used, so the I2C connection is the only one > left. > > I have made it work with 100 kHz clock, but I would like to run 400 > kHz. I have checked that all the devices should be able to handle the > 400 kHz clock. In the setup the Gumstix is the Master. Jakob, The SRF08, in its default configuration, takes 65 milliseconds to complete a ranging operation. Are you sure you really need the reduction in data transfer latency you'll get by going to a 400kHz clock? The delay imposed by the sensor itself is much larger. best, -chris ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ gumstix-users mailing list gum...@li... https://lists.sourceforge.net/lists/listinfo/gumstix-users --------------------------------- Start Yahoo! Auction now! Check out the cool campaign |