From: Robert V. IV <ro...@io...> - 2011-04-07 21:06:20
|
Hi all, We are seeing an occasional issue where the Overo is receiving serial data from a PIC and after some period of runtime (probably heating up) the Overo will sometimes see certain characters incorrectly. My assumption is that the clocks are drifting slightly over temperature, and that the baud rates are on the razor edge of compatible. Does anyone know what the actual baud rate is that results when the Overo is set to 115200 in the kernel? Thanks! Robert Vogt IV CEO IOSiX, LLC 2375 Parkwood Ave Ypsilanti, MI 48198 ro...@io... P: 734-730-9690 F: 734-482-2337 |
From: J. L. <vwy...@gm...> - 2011-04-07 21:51:48
|
Do you mean the razor 9DOF IMU? if so while I was still using mine was running 57600. I also have a heat sink on my overo and there is constant airflow and only runs a 2 hour mission tops, so have never run into heat issues as of yet. If I remember correctly it defaults to 38400. Sorry if that wasnt what you meant. On Thu, Apr 7, 2011 at 2:05 PM, Robert Vogt IV <ro...@io...> wrote: > Hi all, > > We are seeing an occasional issue where the Overo is receiving serial data > from a PIC and after some period of runtime (probably heating up) the Overo > will sometimes see certain characters incorrectly. My assumption is that > the clocks are drifting slightly over temperature, and that the baud rates > are on the razor edge of compatible. Does anyone know what the actual baud > rate is that results when the Overo is set to 115200 in the kernel? Thanks! > > > Robert Vogt IV > CEO > IOSiX, LLC > 2375 Parkwood Ave > Ypsilanti, MI 48198 > ro...@io... > P: 734-730-9690 > F: 734-482-2337 > > > ------------------------------------------------------------------------------ > Xperia(TM) PLAY > It's a major breakthrough. An authentic gaming > smartphone on the nation's most reliable network. > And it wants your games. > http://p.sf.net/sfu/verizon-sfdev > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > |
From: Robert V. IV <ro...@io...> - 2011-04-07 22:03:25
|
Hi JL, No, the baud rate is usually divided from the system clock. For instance, a PIC18 running at 16 Mhz trying to output a 115200 clock might use a baud rate generator value of 1, yielding 125000, an 8.51% error. My question is, at 115200, what kind of error is it, and what is the true baud rate? From that, I can adjust the PIC32 baud rate to be closer. For instance, if the Overo is running at 117000, and the PIC32 is running at 113000, then really I should be targeting the Overo 'actual' baud rate to get the best communication. Thanks. Robert Vogt IV CEO IOSiX, LLC 2375 Parkwood Ave Ypsilanti, MI 48198 ro...@io... P: 734-730-9690 F: 734-482-2337 On Thu, Apr 7, 2011 at 5:51 PM, J. L. <vwy...@gm...> wrote: > Do you mean the razor 9DOF IMU? if so while I was still using mine was > running 57600. I also have a heat sink on my overo and there is constant > airflow and only runs a 2 hour mission tops, so have never run into heat > issues as of yet. If I remember correctly it defaults to 38400. Sorry if > that wasnt what you meant. > > > > On Thu, Apr 7, 2011 at 2:05 PM, Robert Vogt IV <ro...@io...> wrote: > >> Hi all, >> >> We are seeing an occasional issue where the Overo is receiving serial data >> from a PIC and after some period of runtime (probably heating up) the Overo >> will sometimes see certain characters incorrectly. My assumption is that >> the clocks are drifting slightly over temperature, and that the baud rates >> are on the razor edge of compatible. Does anyone know what the actual baud >> rate is that results when the Overo is set to 115200 in the kernel? Thanks! >> >> >> Robert Vogt IV >> CEO >> IOSiX, LLC >> 2375 Parkwood Ave >> Ypsilanti, MI 48198 >> ro...@io... >> P: 734-730-9690 >> F: 734-482-2337 >> >> >> ------------------------------------------------------------------------------ >> Xperia(TM) PLAY >> It's a major breakthrough. An authentic gaming >> smartphone on the nation's most reliable network. >> And it wants your games. >> http://p.sf.net/sfu/verizon-sfdev >> _______________________________________________ >> gumstix-users mailing list >> gum...@li... >> https://lists.sourceforge.net/lists/listinfo/gumstix-users >> >> > > > ------------------------------------------------------------------------------ > Xperia(TM) PLAY > It's a major breakthrough. An authentic gaming > smartphone on the nation's most reliable network. > And it wants your games. > http://p.sf.net/sfu/verizon-sfdev > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > |
From: J. L. <vwy...@gm...> - 2011-04-07 22:10:41
|
Got ya sorry you just said razor edge and the IMU I was talking about is called that, sorry for the mix up On Thu, Apr 7, 2011 at 3:02 PM, Robert Vogt IV <ro...@io...> wrote: > Hi JL, > > No, the baud rate is usually divided from the system clock. For instance, > a PIC18 running at 16 Mhz trying to output a 115200 clock might use a baud > rate generator value of 1, yielding 125000, an 8.51% error. My question is, > at 115200, what kind of error is it, and what is the true baud rate? From > that, I can adjust the PIC32 baud rate to be closer. For instance, if the > Overo is running at 117000, and the PIC32 is running at 113000, then really > I should be targeting the Overo 'actual' baud rate to get the best > communication. Thanks. > > > > Robert Vogt IV > CEO > IOSiX, LLC > 2375 Parkwood Ave > Ypsilanti, MI 48198 > ro...@io... > P: 734-730-9690 > F: 734-482-2337 > > > On Thu, Apr 7, 2011 at 5:51 PM, J. L. <vwy...@gm...> wrote: > >> Do you mean the razor 9DOF IMU? if so while I was still using mine was >> running 57600. I also have a heat sink on my overo and there is constant >> airflow and only runs a 2 hour mission tops, so have never run into heat >> issues as of yet. If I remember correctly it defaults to 38400. Sorry if >> that wasnt what you meant. >> >> >> >> On Thu, Apr 7, 2011 at 2:05 PM, Robert Vogt IV <ro...@io...> wrote: >> >>> Hi all, >>> >>> We are seeing an occasional issue where the Overo is receiving serial >>> data from a PIC and after some period of runtime (probably heating up) the >>> Overo will sometimes see certain characters incorrectly. My assumption is >>> that the clocks are drifting slightly over temperature, and that the baud >>> rates are on the razor edge of compatible. Does anyone know what the actual >>> baud rate is that results when the Overo is set to 115200 in the kernel? >>> Thanks! >>> >>> >>> Robert Vogt IV >>> CEO >>> IOSiX, LLC >>> 2375 Parkwood Ave >>> Ypsilanti, MI 48198 >>> ro...@io... >>> P: 734-730-9690 >>> F: 734-482-2337 >>> >>> >>> ------------------------------------------------------------------------------ >>> Xperia(TM) PLAY >>> It's a major breakthrough. An authentic gaming >>> smartphone on the nation's most reliable network. >>> And it wants your games. >>> http://p.sf.net/sfu/verizon-sfdev >>> _______________________________________________ >>> gumstix-users mailing list >>> gum...@li... >>> https://lists.sourceforge.net/lists/listinfo/gumstix-users >>> >>> >> >> >> ------------------------------------------------------------------------------ >> Xperia(TM) PLAY >> It's a major breakthrough. An authentic gaming >> smartphone on the nation's most reliable network. >> And it wants your games. >> http://p.sf.net/sfu/verizon-sfdev >> _______________________________________________ >> gumstix-users mailing list >> gum...@li... >> https://lists.sourceforge.net/lists/listinfo/gumstix-users >> >> > > > ------------------------------------------------------------------------------ > Xperia(TM) PLAY > It's a major breakthrough. An authentic gaming > smartphone on the nation's most reliable network. > And it wants your games. > http://p.sf.net/sfu/verizon-sfdev > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > |
From: Ned F. <nfo...@wh...> - 2011-04-07 22:16:27
|
How about using an oscilloscope to simply measure? Check the transmit output from each device to find its actual baud rate. While there you can check the signal levels to see if that is the real problem. On 04/07/2011 06:02 PM, Robert Vogt IV wrote: > Hi JL, > > No, the baud rate is usually divided from the system clock. For instance, a > PIC18 running at 16 Mhz trying to output a 115200 clock might use a baud > rate generator value of 1, yielding 125000, an 8.51% error. My question is, > at 115200, what kind of error is it, and what is the true baud rate? From > that, I can adjust the PIC32 baud rate to be closer. For instance, if the > Overo is running at 117000, and the PIC32 is running at 113000, then really > I should be targeting the Overo 'actual' baud rate to get the best > communication. Thanks. > > > Robert Vogt IV > CEO > IOSiX, LLC > 2375 Parkwood Ave > Ypsilanti, MI 48198 > ro...@io... > P: 734-730-9690 > F: 734-482-2337 > > > On Thu, Apr 7, 2011 at 5:51 PM, J. L. <vwy...@gm...> wrote: > >> Do you mean the razor 9DOF IMU? if so while I was still using mine was >> running 57600. I also have a heat sink on my overo and there is constant >> airflow and only runs a 2 hour mission tops, so have never run into heat >> issues as of yet. If I remember correctly it defaults to 38400. Sorry if >> that wasnt what you meant. >> >> >> >> On Thu, Apr 7, 2011 at 2:05 PM, Robert Vogt IV <ro...@io...> wrote: >> >>> Hi all, >>> >>> We are seeing an occasional issue where the Overo is receiving serial data >>> from a PIC and after some period of runtime (probably heating up) the Overo >>> will sometimes see certain characters incorrectly. My assumption is that >>> the clocks are drifting slightly over temperature, and that the baud rates >>> are on the razor edge of compatible. Does anyone know what the actual baud >>> rate is that results when the Overo is set to 115200 in the kernel? Thanks! >>> >>> >>> Robert Vogt IV >>> CEO >>> IOSiX, LLC >>> 2375 Parkwood Ave >>> Ypsilanti, MI 48198 >>> ro...@io... >>> P: 734-730-9690 >>> F: 734-482-2337 >>> >>> >>> ------------------------------------------------------------------------------ >>> Xperia(TM) PLAY >>> It's a major breakthrough. An authentic gaming >>> smartphone on the nation's most reliable network. >>> And it wants your games. >>> http://p.sf.net/sfu/verizon-sfdev >>> _______________________________________________ >>> gumstix-users mailing list >>> gum...@li... >>> https://lists.sourceforge.net/lists/listinfo/gumstix-users >>> >>> >> >> >> ------------------------------------------------------------------------------ >> Xperia(TM) PLAY >> It's a major breakthrough. An authentic gaming >> smartphone on the nation's most reliable network. >> And it wants your games. >> http://p.sf.net/sfu/verizon-sfdev >> _______________________________________________ >> gumstix-users mailing list >> gum...@li... >> https://lists.sourceforge.net/lists/listinfo/gumstix-users >> >> > > > > ------------------------------------------------------------------------------ > Xperia(TM) PLAY > It's a major breakthrough. An authentic gaming > smartphone on the nation's most reliable network. > And it wants your games. > http://p.sf.net/sfu/verizon-sfdev > > > > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users -- Ned Forrester nfo...@wh... Oceanographic Systems Lab 508-289-2226 Office / 774-392-5352 Cell Applied Ocean Physics and Engineering Dept. Woods Hole Oceanographic Institution Woods Hole, MA 02543, USA http://www.whoi.edu/ http://www.whoi.edu/page.do?pid=29856 http://www.whoi.edu/hpb/Site.do?id=1532 |
From: Jeff D. <je...@gr...> - 2011-04-07 23:37:59
|
According to the OMAP TRM, the baud rates are generated from a fixed 48 MHz clock, yielding a maximum baud rate error of 0.16% at standard rates. Jeff DeFouw<je...@gr...> Programmer Grand Rapids Technologies On 4/7/2011 6:02 PM, Robert Vogt IV wrote: > Hi JL, > > No, the baud rate is usually divided from the system clock. For instance, a > PIC18 running at 16 Mhz trying to output a 115200 clock might use a baud > rate generator value of 1, yielding 125000, an 8.51% error. My question is, > at 115200, what kind of error is it, and what is the true baud rate? From > that, I can adjust the PIC32 baud rate to be closer. For instance, if the > Overo is running at 117000, and the PIC32 is running at 113000, then really > I should be targeting the Overo 'actual' baud rate to get the best > communication. Thanks. > > > Robert Vogt IV > CEO > IOSiX, LLC > 2375 Parkwood Ave > Ypsilanti, MI 48198 > ro...@io... <mailto:ro...@io...> > P: 734-730-9690 > F: 734-482-2337 > > > On Thu, Apr 7, 2011 at 5:51 PM, J. L. <vwy...@gm... > <mailto:vwy...@gm...>> wrote: > > Do you mean the razor 9DOF IMU? if so while I was still using mine was > running 57600. I also have a heat sink on my overo and there is constant > airflow and only runs a 2 hour mission tops, so have never run into heat > issues as of yet. If I remember correctly it defaults to 38400. Sorry > if that wasnt what you meant. > > > > On Thu, Apr 7, 2011 at 2:05 PM, Robert Vogt IV <ro...@io... > <mailto:ro...@io...>> wrote: > > Hi all, > > We are seeing an occasional issue where the Overo is receiving > serial data from a PIC and after some period of runtime (probably > heating up) the Overo will sometimes see certain characters > incorrectly. My assumption is that the clocks are drifting slightly > over temperature, and that the baud rates are on the razor edge of > compatible. Does anyone know what the actual baud rate is that > results when the Overo is set to 115200 in the kernel? Thanks! > > > Robert Vogt IV > CEO > IOSiX, LLC > 2375 Parkwood Ave > Ypsilanti, MI 48198 > ro...@io... <mailto:ro...@io...> > P: 734-730-9690 <tel:734-730-9690> > F: 734-482-2337 <tel:734-482-2337> > > ------------------------------------------------------------------------------ > Xperia(TM) PLAY > It's a major breakthrough. An authentic gaming > smartphone on the nation's most reliable network. > And it wants your games. > http://p.sf.net/sfu/verizon-sfdev > _______________________________________________ > gumstix-users mailing list > gum...@li... > <mailto:gum...@li...> > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > > > ------------------------------------------------------------------------------ > Xperia(TM) PLAY > It's a major breakthrough. An authentic gaming > smartphone on the nation's most reliable network. > And it wants your games. > http://p.sf.net/sfu/verizon-sfdev > _______________________________________________ > gumstix-users mailing list > gum...@li... > <mailto:gum...@li...> > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > > > ------------------------------------------------------------------------------ > Xperia(TM) PLAY > It's a major breakthrough. An authentic gaming > smartphone on the nation's most reliable network. > And it wants your games. > http://p.sf.net/sfu/verizon-sfdev > > > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users |
From: Devin H. <dkh...@gm...> - 2011-04-08 12:38:11
|
Hi, My experience with the PIC UARTS is that they are the source of the error, especially at the 115200 baud rate (I'm basing this off of the dspic33f's that I use regularly). If you have access to an oscilloscope you can measure the bit times on the TX pins of both the OMAP and the PIC and easily figure out if one is drifting. Just a thought. Best, Devin On 4/7/2011 7:37 PM, Jeff DeFouw wrote: > According to the OMAP TRM, the baud rates are generated from a fixed > 48 MHz clock, yielding a maximum baud rate error of 0.16% at standard > rates. > Jeff DeFouw<je...@gr...> > Programmer > Grand Rapids Technologies > > On 4/7/2011 6:02 PM, Robert Vogt IV wrote: >> Hi JL, >> >> No, the baud rate is usually divided from the system clock. For >> instance, a PIC18 running at 16 Mhz trying to output a 115200 clock >> might use a baud rate generator value of 1, yielding 125000, an 8.51% >> error. My question is, at 115200, what kind of error is it, and what >> is the true baud rate? From that, I can adjust the PIC32 baud rate >> to be closer. For instance, if the Overo is running at 117000, and >> the PIC32 is running at 113000, then really I should be targeting the >> Overo 'actual' baud rate to get the best communication. Thanks. >> >> >> Robert Vogt IV >> CEO >> IOSiX, LLC >> 2375 Parkwood Ave >> Ypsilanti, MI 48198 >> ro...@io... <mailto:ro...@io...> >> P: 734-730-9690 >> F: 734-482-2337 >> >> >> On Thu, Apr 7, 2011 at 5:51 PM, J. L. <vwy...@gm... >> <mailto:vwy...@gm...>> wrote: >> >> Do you mean the razor 9DOF IMU? if so while I was still using >> mine was running 57600. I also have a heat sink on my overo and >> there is constant airflow and only runs a 2 hour mission tops, so >> have never run into heat issues as of yet. If I remember >> correctly it defaults to 38400. Sorry if that wasnt what you meant. >> >> >> >> On Thu, Apr 7, 2011 at 2:05 PM, Robert Vogt IV <ro...@io... >> <mailto:ro...@io...>> wrote: >> >> Hi all, >> >> We are seeing an occasional issue where the Overo is >> receiving serial data from a PIC and after some period of >> runtime (probably heating up) the Overo will sometimes see >> certain characters incorrectly. My assumption is that the >> clocks are drifting slightly over temperature, and that the >> baud rates are on the razor edge of compatible. Does anyone >> know what the actual baud rate is that results when the Overo >> is set to 115200 in the kernel? Thanks! >> >> >> Robert Vogt IV >> CEO >> IOSiX, LLC >> 2375 Parkwood Ave >> Ypsilanti, MI 48198 >> ro...@io... <mailto:ro...@io...> >> P: 734-730-9690 <tel:734-730-9690> >> F: 734-482-2337 <tel:734-482-2337> >> >> ------------------------------------------------------------------------------ >> Xperia(TM) PLAY >> It's a major breakthrough. An authentic gaming >> smartphone on the nation's most reliable network. >> And it wants your games. >> http://p.sf.net/sfu/verizon-sfdev >> _______________________________________________ >> gumstix-users mailing list >> gum...@li... >> <mailto:gum...@li...> >> https://lists.sourceforge.net/lists/listinfo/gumstix-users >> >> >> >> ------------------------------------------------------------------------------ >> Xperia(TM) PLAY >> It's a major breakthrough. An authentic gaming >> smartphone on the nation's most reliable network. >> And it wants your games. >> http://p.sf.net/sfu/verizon-sfdev >> _______________________________________________ >> gumstix-users mailing list >> gum...@li... >> <mailto:gum...@li...> >> https://lists.sourceforge.net/lists/listinfo/gumstix-users >> >> >> >> ------------------------------------------------------------------------------ >> Xperia(TM) PLAY >> It's a major breakthrough. An authentic gaming >> smartphone on the nation's most reliable network. >> And it wants your games. >> http://p.sf.net/sfu/verizon-sfdev >> >> >> _______________________________________________ >> gumstix-users mailing list >> gum...@li... >> https://lists.sourceforge.net/lists/listinfo/gumstix-users > > > ------------------------------------------------------------------------------ > Xperia(TM) PLAY > It's a major breakthrough. An authentic gaming > smartphone on the nation's most reliable network. > And it wants your games. > http://p.sf.net/sfu/verizon-sfdev > > > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users |