From: rlboyd <rl...@gm...> - 2007-11-06 14:39:39
|
This may or may not have already been answered but I am going to ask anyways. I did a quick search and did not find a definitive answer. I am about to try and use the i2c bus on my verdex + breakout-vx and I was wondering if the combination of boards has the i2c pull up restores or not or if I should add my own. Anyone know for sure? Thanks, Richard -- View this message in context: http://www.nabble.com/verdex-%2B-breakout-vx-i2c-pullup-tf4758476.html#a13607975 Sent from the Gumstix mailing list archive at Nabble.com. |
From: Dave H. <dhy...@gm...> - 2007-11-06 15:17:47
|
Hi Richard, > This may or may not have already been answered but I am going to ask anyways. > I did a quick search and did not find a definitive answer. > > I am about to try and use the i2c bus on my verdex + breakout-vx and I was > wondering if the combination of boards has the i2c pull up restores or not > or if I should add my own. Anyone know for sure? According to Gordon: <http://article.gmane.org/gmane.linux.distributions.gumstix.general/30925> there are pullups on the verdex. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: thaGod <th...@gm...> - 2007-11-08 00:36:36
|
Hehe... true, but according to a scope it doesn't. Erick Dave Hylands wrote: > > Hi Richard, > >> This may or may not have already been answered but I am going to ask >> anyways. >> I did a quick search and did not find a definitive answer. >> >> I am about to try and use the i2c bus on my verdex + breakout-vx and I >> was >> wondering if the combination of boards has the i2c pull up restores or >> not >> or if I should add my own. Anyone know for sure? > > According to Gordon: > <http://article.gmane.org/gmane.linux.distributions.gumstix.general/30925> > there are pullups on the verdex. > > -- > Dave Hylands > Vancouver, BC, Canada > http://www.DaveHylands.com/ > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > -- View this message in context: http://www.nabble.com/verdex-%2B-breakout-vx-i2c-pullup-tf4758476.html#a13639320 Sent from the Gumstix mailing list archive at Nabble.com. |
From: Dave H. <dhy...@gm...> - 2007-11-08 01:12:29
|
Hi Gordon, > Hehe... true, but according to a scope it doesn't. So that's a good point, which reminds me, on the 270 there are two i2c busses, one intended for power management chip and one for general purpose. Are the pullups on both busses? Or just the PMU one? -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: thaGod <th...@gm...> - 2007-11-08 01:28:32
|
Not to keep interrupting.. but don't forget the penirq line too. That line was perpetually low just like the SCL and SDA. I added a 75K to vcc on that line too per tsc2003 datasheet spec. Erick Dave Hylands wrote: > > Hi Gordon, > >> Hehe... true, but according to a scope it doesn't. > > So that's a good point, which reminds me, on the 270 there are two i2c > busses, one intended for power management chip and one for general > purpose. > > Are the pullups on both busses? Or just the PMU one? > > -- > Dave Hylands > Vancouver, BC, Canada > http://www.DaveHylands.com/ > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > -- View this message in context: http://www.nabble.com/verdex-%2B-breakout-vx-i2c-pullup-tf4758476.html#a13639831 Sent from the Gumstix mailing list archive at Nabble.com. |
From: Richard B. <rl...@gm...> - 2007-11-08 18:55:37
|
My main concern is the i2c bus the is broken out on the breakou-vx. I am not sure which of the two that is though. So it sounds to me like we should be assuming that the pull up resistors ARE required. I don't have a scope so I am trying to figure out what others have found they needed to get this to work. thaGod feel free to interrupt as much as you like. I do it all the time. ;) Richard On Nov 7, 2007 9:28 PM, thaGod <th...@gm...> wrote: > > Not to keep interrupting.. but don't forget the penirq line too. That line > was perpetually low just like the SCL and SDA. I added a 75K to vcc on that > line too per tsc2003 datasheet spec. > > Erick > > > > Dave Hylands wrote: > > > > Hi Gordon, > > > >> Hehe... true, but according to a scope it doesn't. > > > > So that's a good point, which reminds me, on the 270 there are two i2c > > busses, one intended for power management chip and one for general > > purpose. > > > > Are the pullups on both busses? Or just the PMU one? > > > > -- > > Dave Hylands > > Vancouver, BC, Canada > > http://www.DaveHylands.com/ > > > > ------------------------------------------------------------------------- > > This SF.net email is sponsored by: Splunk Inc. > > Still grepping through log files to find problems? Stop. > > Now Search log events and configuration files using AJAX and a browser. > > Download your FREE copy of Splunk now >> http://get.splunk.com/ > > _______________________________________________ > > gumstix-users mailing list > > gum...@li... > > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > > > > > -- > View this message in context: http://www.nabble.com/verdex-%2B-breakout-vx-i2c-pullup-tf4758476.html#a13639831 > Sent from the Gumstix mailing list archive at Nabble.com. > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > |
From: Dave H. <dhy...@gm...> - 2007-11-08 19:06:59
|
Hi Richard, On 11/8/07, Richard Boyd <rl...@gm...> wrote: > My main concern is the i2c bus the is broken out on the breakou-vx. I > am not sure which of the two that is though. So it sounds to me like > we should be assuming that the pull up resistors ARE required. I don't > have a scope so I am trying to figure out what others have found they > needed to get this to work. The i2c bus brought out on the hirose connector is the standard one. I've used it successfully with my robostix, but the robostix has its own pullups. When you load the i2c-pxa module, you'll see /dev/i2c-0 and i2c-1. i2c-0 is the one that goes to the hirose and i2c-1 is for the power control. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: thaGod <th...@gm...> - 2007-11-08 23:20:41
|
I'd like to give your i2c test programs some more trials on my verdex someday Dave. I know I've got something else configured wrong because even with all my lines pulled up (and verified pulled up on the scope) I was unable to get anything to work right as far as I could tell. My main test case was the tsc2003 driver and whenever I loaded both the tsc2003 and i2c-pxa modules I got a waiting for bus to free error message. Someday I'd like to get to the bottom of it. Erick Dave Hylands wrote: > > Hi Richard, > > On 11/8/07, Richard Boyd <rl...@gm...> wrote: >> My main concern is the i2c bus the is broken out on the breakou-vx. I >> am not sure which of the two that is though. So it sounds to me like >> we should be assuming that the pull up resistors ARE required. I don't >> have a scope so I am trying to figure out what others have found they >> needed to get this to work. > > The i2c bus brought out on the hirose connector is the standard one. > I've used it successfully with my robostix, but the robostix has its > own pullups. > > When you load the i2c-pxa module, you'll see /dev/i2c-0 and i2c-1. > i2c-0 is the one that goes to the hirose and i2c-1 is for the power > control. > > -- > Dave Hylands > Vancouver, BC, Canada > http://www.DaveHylands.com/ > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > -- View this message in context: http://www.nabble.com/verdex-%2B-breakout-vx-i2c-pullup-tf4758476.html#a13658199 Sent from the Gumstix mailing list archive at Nabble.com. |
From: Dave H. <dhy...@gm...> - 2007-11-09 00:11:31
|
Hi Erick, > I'd like to give your i2c test programs some more trials on my verdex someday > Dave. I know I've got something else configured wrong because even with all > my lines pulled up (and verified pulled up on the scope) I was unable to get > anything to work right as far as I could tell. > > My main test case was the tsc2003 driver and whenever I loaded both the > tsc2003 and i2c-pxa modules I got a waiting for bus to free error message. > Someday I'd like to get to the bottom of it. Waiting for bus free means that the SCL signal (and/or SDA - I don't remember exactly) is being held low. When the bus is idle, then both SDA and SCL should be sitting at 3.3v -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: thaGod <th...@gm...> - 2007-11-09 00:44:10
|
Yeah.. that's i2c 101 =) I had both lines pulled up and still got bus waiting for free messages.. but only when the tsc2003 driver was loaded at the same time as the i2c-pxa module. It didn't matter which order they were loaded in.. either order gave me the same errors when the 2nd module was added. Erick Dave Hylands wrote: > > Hi Erick, > >> I'd like to give your i2c test programs some more trials on my verdex >> someday >> Dave. I know I've got something else configured wrong because even with >> all >> my lines pulled up (and verified pulled up on the scope) I was unable to >> get >> anything to work right as far as I could tell. >> >> My main test case was the tsc2003 driver and whenever I loaded both the >> tsc2003 and i2c-pxa modules I got a waiting for bus to free error >> message. >> Someday I'd like to get to the bottom of it. > > Waiting for bus free means that the SCL signal (and/or SDA - I don't > remember exactly) is being held low. > > When the bus is idle, then both SDA and SCL should be sitting at 3.3v > > -- > Dave Hylands > Vancouver, BC, Canada > http://www.DaveHylands.com/ > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > -- View this message in context: http://www.nabble.com/verdex-%2B-breakout-vx-i2c-pullup-tf4758476.html#a13659314 Sent from the Gumstix mailing list archive at Nabble.com. |
From: Richard B. <rl...@gm...> - 2007-11-09 13:52:51
|
I just did a quick check of the i2c pins with a multi meter on my board and they are all low. I have no i2c devices connect and, at least I think, I have the i2c stuff compiled into the build. I guess this means that I need I2c pull ups. Correct? Richard On Nov 8, 2007 8:44 PM, thaGod <th...@gm...> wrote: > > Yeah.. that's i2c 101 =) > > I had both lines pulled up and still got bus waiting for free messages.. but > only when the tsc2003 driver was loaded at the same time as the i2c-pxa > module. It didn't matter which order they were loaded in.. either order gave > me the same errors when the 2nd module was added. > > Erick > > > > Dave Hylands wrote: > > > > Hi Erick, > > > >> I'd like to give your i2c test programs some more trials on my verdex > >> someday > >> Dave. I know I've got something else configured wrong because even with > >> all > >> my lines pulled up (and verified pulled up on the scope) I was unable to > >> get > >> anything to work right as far as I could tell. > >> > >> My main test case was the tsc2003 driver and whenever I loaded both the > >> tsc2003 and i2c-pxa modules I got a waiting for bus to free error > >> message. > >> Someday I'd like to get to the bottom of it. > > > > Waiting for bus free means that the SCL signal (and/or SDA - I don't > > remember exactly) is being held low. > > > > When the bus is idle, then both SDA and SCL should be sitting at 3.3v > > > > -- > > Dave Hylands > > Vancouver, BC, Canada > > http://www.DaveHylands.com/ > > > > ------------------------------------------------------------------------- > > This SF.net email is sponsored by: Splunk Inc. > > Still grepping through log files to find problems? Stop. > > Now Search log events and configuration files using AJAX and a browser. > > Download your FREE copy of Splunk now >> http://get.splunk.com/ > > _______________________________________________ > > gumstix-users mailing list > > gum...@li... > > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > > > > > -- > View this message in context: http://www.nabble.com/verdex-%2B-breakout-vx-i2c-pullup-tf4758476.html#a13659314 > Sent from the Gumstix mailing list archive at Nabble.com. > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > |
From: thaGod <th...@gm...> - 2007-11-09 18:40:59
|
Well I don't know how well you can tell with a multimeter, but I do know that adding a couple 1.2K resistors (per datasheet callout) won't adversely affect anything even if there are already pullups there. You could add them just to be sure. The datasheet also calls for a 50K to be added to the penirq line. So that's 1.2K or higher value resistors ( try to stay close ) between pins 11 and 12 of the tsc2003 and pin 1 of the tsc2003... and 1 50K resistor between pin 10 and pin 1 of the tsc2003 I think I said 75K before.. that was wrong. Erick rlboyd wrote: > > I just did a quick check of the i2c pins with a multi meter on my > board and they are all low. I have no i2c devices connect and, at > least I think, I have the i2c stuff compiled into the build. > > I guess this means that I need I2c pull ups. Correct? > > Richard > > On Nov 8, 2007 8:44 PM, thaGod <th...@gm...> wrote: >> >> Yeah.. that's i2c 101 =) >> >> I had both lines pulled up and still got bus waiting for free messages.. >> but >> only when the tsc2003 driver was loaded at the same time as the i2c-pxa >> module. It didn't matter which order they were loaded in.. either order >> gave >> me the same errors when the 2nd module was added. >> >> Erick >> >> >> >> Dave Hylands wrote: >> > >> > Hi Erick, >> > >> >> I'd like to give your i2c test programs some more trials on my verdex >> >> someday >> >> Dave. I know I've got something else configured wrong because even >> with >> >> all >> >> my lines pulled up (and verified pulled up on the scope) I was unable >> to >> >> get >> >> anything to work right as far as I could tell. >> >> >> >> My main test case was the tsc2003 driver and whenever I loaded both >> the >> >> tsc2003 and i2c-pxa modules I got a waiting for bus to free error >> >> message. >> >> Someday I'd like to get to the bottom of it. >> > >> > Waiting for bus free means that the SCL signal (and/or SDA - I don't >> > remember exactly) is being held low. >> > >> > When the bus is idle, then both SDA and SCL should be sitting at 3.3v >> > >> > -- >> > Dave Hylands >> > Vancouver, BC, Canada >> > http://www.DaveHylands.com/ >> > >> > >> ------------------------------------------------------------------------- >> > This SF.net email is sponsored by: Splunk Inc. >> > Still grepping through log files to find problems? Stop. >> > Now Search log events and configuration files using AJAX and a browser. >> > Download your FREE copy of Splunk now >> http://get.splunk.com/ >> > _______________________________________________ >> > gumstix-users mailing list >> > gum...@li... >> > https://lists.sourceforge.net/lists/listinfo/gumstix-users >> > >> > >> >> -- >> View this message in context: >> http://www.nabble.com/verdex-%2B-breakout-vx-i2c-pullup-tf4758476.html#a13659314 >> Sent from the Gumstix mailing list archive at Nabble.com. >> >> >> >> ------------------------------------------------------------------------- >> This SF.net email is sponsored by: Splunk Inc. >> Still grepping through log files to find problems? Stop. >> Now Search log events and configuration files using AJAX and a browser. >> Download your FREE copy of Splunk now >> http://get.splunk.com/ >> _______________________________________________ >> gumstix-users mailing list >> gum...@li... >> https://lists.sourceforge.net/lists/listinfo/gumstix-users >> > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > -- View this message in context: http://www.nabble.com/verdex-%2B-breakout-vx-i2c-pullup-tf4758476.html#a13672551 Sent from the Gumstix mailing list archive at Nabble.com. |
From: Dave H. <dhy...@gm...> - 2007-11-09 20:23:38
|
Hi, > Well I don't know how well you can tell with a multimeter, but I do know that > adding a couple 1.2K resistors (per datasheet callout) won't adversely > affect anything even if there are already pullups there. You could add them > just to be sure. The datasheet also calls for a 50K to be added to the > penirq line. > > So that's 1.2K or higher value resistors ( try to stay close ) between pins > 11 and 12 of the tsc2003 and pin 1 of the tsc2003... and 1 50K resistor > between pin 10 and pin 1 of the tsc2003 I would use a higher resistance. If there were already 4.7k, and you add 1.2k (in parallel), then the effective resistance would be 0.955K. I'd probably use 2.2k or higher, and I think 4.7k is fine. The robostix uses 10k and I have that working just fine with the verdex. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: James T. <ja...@al...> - 2007-11-09 20:28:48
|
Dave Hylands wrote: > Hi, > > >> Well I don't know how well you can tell with a multimeter, but I do know that >> adding a couple 1.2K resistors (per datasheet callout) won't adversely >> affect anything even if there are already pullups there. You could add them >> just to be sure. The datasheet also calls for a 50K to be added to the >> penirq line. >> >> So that's 1.2K or higher value resistors ( try to stay close ) between pins >> 11 and 12 of the tsc2003 and pin 1 of the tsc2003... and 1 50K resistor >> between pin 10 and pin 1 of the tsc2003 >> > > I would use a higher resistance. If there were already 4.7k, and you > add 1.2k (in parallel), then the effective resistance would be 0.955K. > > I'd probably use 2.2k or higher, and I think 4.7k is fine. The > robostix uses 10k and I have that working just fine with the verdex. > > I'll second Dave's advice. I inadvertently had two sets of pullups on my I2C bus (two different PCBs) and it did in fact cause problems talking with some devices. -- James Tilley Electrical Engineer Alaska Native Technologies, LLC 360-697-6785 x 314 |
From: Richard B. <rl...@gm...> - 2007-11-09 20:30:57
|
Thanks for the information gentlemen. On Nov 9, 2007 4:31 PM, James Tilley <ja...@al...> wrote: > > > Dave Hylands wrote: > > Hi, > > > > > >> Well I don't know how well you can tell with a multimeter, but I do know that > >> adding a couple 1.2K resistors (per datasheet callout) won't adversely > >> affect anything even if there are already pullups there. You could add them > >> just to be sure. The datasheet also calls for a 50K to be added to the > >> penirq line. > >> > >> So that's 1.2K or higher value resistors ( try to stay close ) between pins > >> 11 and 12 of the tsc2003 and pin 1 of the tsc2003... and 1 50K resistor > >> between pin 10 and pin 1 of the tsc2003 > >> > > > > I would use a higher resistance. If there were already 4.7k, and you > > add 1.2k (in parallel), then the effective resistance would be 0.955K. > > > > I'd probably use 2.2k or higher, and I think 4.7k is fine. The > > robostix uses 10k and I have that working just fine with the verdex. > > > > > > I'll second Dave's advice. > > I inadvertently had two sets of pullups on my I2C bus (two different > PCBs) and it did in fact cause problems talking with some devices. > > -- > James Tilley > Electrical Engineer > Alaska Native Technologies, LLC > 360-697-6785 x 314 > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > |