From: Vaibhav G. <vai...@gm...> - 2009-10-29 00:38:51
|
hi everyone I am referring to pin .I2C SCL (Port D.0) labelled RX . I am using the i2c-test program to cycle between 3 states - making this pin as input, making this as output and driving it low, making this as output and driving it high. The problem is when I drive it high it only goes to 2.5 V. On driving it low I get 0 V which is fine. On turning it to input I get 0.42 V even though it is pulled high. On repeating the same procedure on I2C SDA (Port D.1) labelled TX, it works fine. When I turn this pin to input it gives me 5V, because it is pulled up. On driving it low I get 0 V. And on driving it high I get 5 V. I should be getting the same behaviour from the other pin as well. I removed the pull-up to VCC from the SCL pin and even now if I drive it high I only get 2.5 V. On turning it to input or driving it low I get 0 V. Any help would be greatly appreciated. Vaibhav -- http://guidance.aero.iisc.ernet.in/vaibhav |
From: Dave H. <dhy...@gm...> - 2009-10-29 01:10:39
|
Hi Vaibhav, On Wed, Oct 28, 2009 at 5:38 PM, Vaibhav Ghadiok <vai...@gm...> wrote: > hi everyone > > I am referring to pin .I2C SCL (Port D.0) labelled RX . > > I am using the i2c-test program to cycle between 3 states - making this pin > as input, making this as output and driving it low, making this as output > and driving it high. > > The problem is when I drive it high it only goes to 2.5 V. On driving it low > I get 0 V which is fine. On turning it to input I get 0.42 V even though it > is pulled high. > > On repeating the same procedure on I2C SDA (Port D.1) labelled TX, it works > fine. When I turn this pin to input it gives me 5V, because it is pulled up. > On driving it low I get 0 V. And on driving it high I get 5 V. I should be > getting the same behaviour from the other pin as well. > > I removed the pull-up to VCC from the SCL pin and even now if I drive it > high I only get 2.5 V. On turning it to input or driving it low I get 0 V. > > Any help would be greatly appreciated. The only thing to do now is to try disconnecting it from the gumstix and seeing if it still behaves the same or not. That will at least isolate if the problem is with the gumstix or robostix. You'll probably need to write a simple program that flashes a LED and at the same time toggles the D.0 pin. Once that's been programmed into the robostix, you should be able to power it off, unplug the gumstix and then power on the robostix and it should run the program. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: VaibhavGhadiok <vai...@gm...> - 2009-10-29 01:57:32
|
I was actually doing the same. I just wrote a simple program to drive the do pin high and it gives me 5V when the robostix is disconnected from the gumstix. As soon as I attach the gumstix the voltage falls to 2.5 V. The modifications I had made to the robostix are as follows. 1. I have shorted the RX, TX for the gumstix in order to be able to program the atmega through the gumstix. 2. I have pulled FFUART RxD (GPIO 34) high. 3. The power connection on he robostix is attached to VCC. 4. And the SCL and SDA pins are pulled high. 5. Also I have a capacitor across VCC-GND on the side where the GPIO pins are. This is just to filter noise. I am really not sure what Gumstix is doing, that is making the pin drop to 2.5 V. Dave Hylands wrote: > > Hi Vaibhav, > > On Wed, Oct 28, 2009 at 5:38 PM, Vaibhav Ghadiok > <vai...@gm...> wrote: >> hi everyone >> >> I am referring to pin .I2C SCL (Port D.0) labelled RX . >> >> I am using the i2c-test program to cycle between 3 states - making this >> pin >> as input, making this as output and driving it low, making this as output >> and driving it high. >> >> The problem is when I drive it high it only goes to 2.5 V. On driving it >> low >> I get 0 V which is fine. On turning it to input I get 0.42 V even though >> it >> is pulled high. >> >> On repeating the same procedure on I2C SDA (Port D.1) labelled TX, it >> works >> fine. When I turn this pin to input it gives me 5V, because it is pulled >> up. >> On driving it low I get 0 V. And on driving it high I get 5 V. I should >> be >> getting the same behaviour from the other pin as well. >> >> I removed the pull-up to VCC from the SCL pin and even now if I drive it >> high I only get 2.5 V. On turning it to input or driving it low I get 0 >> V. >> >> Any help would be greatly appreciated. > > The only thing to do now is to try disconnecting it from the gumstix > and seeing if it still behaves the same or not. That will at least > isolate if the problem is with the gumstix or robostix. > > You'll probably need to write a simple program that flashes a LED and > at the same time toggles the D.0 pin. Once that's been programmed into > the robostix, you should be able to power it off, unplug the gumstix > and then power on the robostix and it should run the program. > > -- > Dave Hylands > Shuswap, BC, Canada > http://www.DaveHylands.com/ > > ------------------------------------------------------------------------------ > Come build with us! The BlackBerry(R) Developer Conference in SF, CA > is the only developer event you need to attend this year. Jumpstart your > developing skills, take BlackBerry mobile applications to market and stay > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > http://p.sf.net/sfu/devconference > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > -- View this message in context: http://www.nabble.com/Robostix-pin-D.0-%28I2C-SCL%29-doesn%27t-drive-high-%28using-i2c-test%29-tp26104495p26105090.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: Dave H. <dhy...@gm...> - 2009-10-29 04:03:57
|
Hi Vaibhav, On Wed, Oct 28, 2009 at 6:57 PM, VaibhavGhadiok <vai...@gm...> wrote: > > I was actually doing the same. I just wrote a simple program to drive the do > pin high and it gives me 5V when the robostix is disconnected from the > gumstix. As soon as I attach the gumstix the voltage falls to 2.5 V. The SDA and SCL signals come from the gumstix, run through a 3.3v to 5v voltage converter and then go to the robostix. On the gumstix side is a pullup from each of these to VCC (3.3v) and on the robostix side is a pullup to VBATT (5v). So you should check those pullups as well. > The modifications I had made to the robostix are as follows. > > 1. I have shorted the RX, TX for the gumstix in order to be able to program > the atmega through the gumstix. > 2. I have pulled FFUART RxD (GPIO 34) high. > 3. The power connection on he robostix is attached to VCC. Hmm. Which VCC? The signal VCC is 3.3v. The signal VCC5 and VBATT are 5v. > 4. And the SCL and SDA pins are pulled high. Hopefully to 5v. > 5. Also I have a capacitor across VCC-GND on the side where the GPIO pins > are. This is just to filter noise. > > I am really not sure what Gumstix is doing, that is making the pin drop to > 2.5 V. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: VaibhavGhadiok <vai...@gm...> - 2009-10-29 19:57:50
|
Hi dave, I am not sure where to check on the gumstix. I have a basix and I am not able to get the schematics. I got this: http://sketchup.google.com/3dwarehouse/details?mid=64bb986a5deac392e55eaf79ca7dc5e7&prevstart=0 But this is not helping. The board is really tiny. I have no clue where to probe. I couldn't figure out the gumstix pins for SDA SCL from the UARTs table given on: http://docwiki.gumstix.org/index.php/Robostix_I/O_pins#In_System_Programming_.28ISP.29 The pin I was talking about in my previous post is the one on the bottom right in the picture showing the bottom side of the robostix board. I have connected that pin to 5v. http://docwiki.gumstix.org/index.php/Robostix_I/O_pins#In_System_Programming_.28ISP.29 Dave Hylands wrote: > > On the gumstix side is a pullup from each of these to VCC (3.3v) and > on the robostix side is a pullup to VBATT (5v). > Thanks. -- View this message in context: http://www.nabble.com/Robostix-pin-D.0-%28I2C-SCL%29-doesn%27t-drive-high-%28using-i2c-test%29-tp26104495p26119707.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: Dave H. <dhy...@gm...> - 2009-10-29 20:55:17
|
Hi Vaibhav, On Thu, Oct 29, 2009 at 12:57 PM, VaibhavGhadiok <vai...@gm...> wrote: > I am not sure where to check on the gumstix. I have a basix and I am not > able to get the schematics. > > I got this: > http://sketchup.google.com/3dwarehouse/details?mid=64bb986a5deac392e55eaf79ca7dc5e7&prevstart=0 > But this is not helping. > > The board is really tiny. I have no clue where to probe. > > I couldn't figure out the gumstix pins for SDA SCL from the UARTs table > given on: > http://docwiki.gumstix.org/index.php/Robostix_I/O_pins#In_System_Programming_.28ISP.29 Just to the left of the white connector is an 8-pin chip. This is the 3.3v to 5v converter for the i2c signals. <http://www.nxp.com/#/pip/pip=[pip=PCA9515_9]|pp=[t=pip,i=PCA9515_9]> Pins 2 & 3 are the 3.3v SCL and SDA signals from the gumstix. Pins 7 & 6 are the corresponding 5v SCL and SDA signals. > The pin I was talking about in my previous post is the one on the bottom > right in the picture showing the bottom side of the robostix board. I have > connected that pin to 5v. > http://docwiki.gumstix.org/index.php/Robostix_I/O_pins#In_System_Programming_.28ISP.29 I think that's the BOARD connector. and that would be the V_ROBOBATT signal, which is the input to the voltage regulators. So 5v on that pin is fine. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: VaibhavGhadiok <vai...@gm...> - 2009-10-29 23:33:48
|
I see a chip as you have described. For me it says LTNX E3. It seems to be from LT. This is to the left of the connector that is used to connect the gumstix to the Tweener/Robostix. In order for me to power the gumstix I need to connect it to either the robostix or the tweener board. In both cases he above specified chip gets covered. Soldering anything on it seemed a bit dangerous. Am I talking about the right chip? Dave Hylands wrote: > > Hi Vaibhav, > > On Thu, Oct 29, 2009 at 12:57 PM, VaibhavGhadiok > <vai...@gm...> wrote: >> I am not sure where to check on the gumstix. I have a basix and I am not >> able to get the schematics. >> >> I got this: >> http://sketchup.google.com/3dwarehouse/details?mid=64bb986a5deac392e55eaf79ca7dc5e7&prevstart=0 >> But this is not helping. >> >> The board is really tiny. I have no clue where to probe. >> >> I couldn't figure out the gumstix pins for SDA SCL from the UARTs table >> given on: >> http://docwiki.gumstix.org/index.php/Robostix_I/O_pins#In_System_Programming_.28ISP.29 > > Just to the left of the white connector is an 8-pin chip. This is the > 3.3v to 5v converter for the i2c signals. > <http://www.nxp.com/#/pip/pip=[pip=PCA9515_9]|pp=[t=pip,i=PCA9515_9]> > > Pins 2 & 3 are the 3.3v SCL and SDA signals from the gumstix. Pins 7 & > 6 are the corresponding 5v SCL and SDA signals. > >> The pin I was talking about in my previous post is the one on the bottom >> right in the picture showing the bottom side of the robostix board. I >> have >> connected that pin to 5v. >> http://docwiki.gumstix.org/index.php/Robostix_I/O_pins#In_System_Programming_.28ISP.29 > > I think that's the BOARD connector. and that would be the V_ROBOBATT > signal, which is the input to the voltage regulators. So 5v on that > pin is fine. > > -- > Dave Hylands > Shuswap, BC, Canada > http://www.DaveHylands.com/ > > ------------------------------------------------------------------------------ > Come build with us! The BlackBerry(R) Developer Conference in SF, CA > is the only developer event you need to attend this year. Jumpstart your > developing skills, take BlackBerry mobile applications to market and stay > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > http://p.sf.net/sfu/devconference > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > -- View this message in context: http://www.nabble.com/Robostix-pin-D.0-%28I2C-SCL%29-doesn%27t-drive-high-%28using-i2c-test%29-tp26104495p26122634.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: VaibhavGhadiok <vai...@gm...> - 2009-10-29 23:44:18
|
I found another 8 pin chip on the other side and it seems to follow what you had stated. 3.3 on pins 2 and 3 and 5 on pins 6 and 7. I was probably looking at the wrong chip. This one is on a corner on the side of the connector that is used to connect to the Wi-Fi stix. VaibhavGhadiok wrote: > > I see a chip as you have described. For me it says LTNX E3. It seems to be > from LT. > > This is to the left of the connector that is used to connect the gumstix > to the Tweener/Robostix. > > In order for me to power the gumstix I need to connect it to either the > robostix or the tweener board. In both cases he above specified chip gets > covered. > > Soldering anything on it seemed a bit dangerous. > > Am I talking about the right chip? > > > Dave Hylands wrote: >> >> Hi Vaibhav, >> >> On Thu, Oct 29, 2009 at 12:57 PM, VaibhavGhadiok >> <vai...@gm...> wrote: >>> I am not sure where to check on the gumstix. I have a basix and I am not >>> able to get the schematics. >>> >>> I got this: >>> http://sketchup.google.com/3dwarehouse/details?mid=64bb986a5deac392e55eaf79ca7dc5e7&prevstart=0 >>> But this is not helping. >>> >>> The board is really tiny. I have no clue where to probe. >>> >>> I couldn't figure out the gumstix pins for SDA SCL from the UARTs table >>> given on: >>> http://docwiki.gumstix.org/index.php/Robostix_I/O_pins#In_System_Programming_.28ISP.29 >> >> Just to the left of the white connector is an 8-pin chip. This is the >> 3.3v to 5v converter for the i2c signals. >> <http://www.nxp.com/#/pip/pip=[pip=PCA9515_9]|pp=[t=pip,i=PCA9515_9]> >> >> Pins 2 & 3 are the 3.3v SCL and SDA signals from the gumstix. Pins 7 & >> 6 are the corresponding 5v SCL and SDA signals. >> >>> The pin I was talking about in my previous post is the one on the bottom >>> right in the picture showing the bottom side of the robostix board. I >>> have >>> connected that pin to 5v. >>> http://docwiki.gumstix.org/index.php/Robostix_I/O_pins#In_System_Programming_.28ISP.29 >> >> I think that's the BOARD connector. and that would be the V_ROBOBATT >> signal, which is the input to the voltage regulators. So 5v on that >> pin is fine. >> >> -- >> Dave Hylands >> Shuswap, BC, Canada >> http://www.DaveHylands.com/ >> >> ------------------------------------------------------------------------------ >> Come build with us! The BlackBerry(R) Developer Conference in SF, CA >> is the only developer event you need to attend this year. Jumpstart your >> developing skills, take BlackBerry mobile applications to market and stay >> ahead of the curve. Join us from November 9 - 12, 2009. Register now! >> http://p.sf.net/sfu/devconference >> _______________________________________________ >> gumstix-users mailing list >> gum...@li... >> https://lists.sourceforge.net/lists/listinfo/gumstix-users >> >> > > -- View this message in context: http://www.nabble.com/Robostix-pin-D.0-%28I2C-SCL%29-doesn%27t-drive-high-%28using-i2c-test%29-tp26104495p26122748.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: Dave H. <dhy...@gm...> - 2009-10-30 00:38:50
|
Hi, On Thu, Oct 29, 2009 at 4:33 PM, VaibhavGhadiok <vai...@gm...> wrote: > > I see a chip as you have described. For me it says LTNX E3. It seems to be > from LT. > > This is to the left of the connector that is used to connect the gumstix to > the Tweener/Robostix. I meant on the robostix board. In this photo: <http://docwiki.gumstix.com/index.php/Robostix_troubleshooting> It's to the right of the VCC that's in red, and above the V_BATT that's in red. You should be able to test the signals without the gumstix connected. When SCL on the robostix side is at 5v, SCL on the gumstix side should be at 3.3v. Similarly for SDA. When one side is at ground, the other side should be at ground. If this looks good, then the problem is almost certainly on the gumstix itself. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: VaibhavGhadiok <vai...@gm...> - 2009-10-30 00:59:43
|
I checked the voltages and they seem to be fine. EN is 5V. VCC for the chip is 3.3V. And the SCL, SDA at pin 2,3 are 3.3V and Pins 6.7 are 5V. Dave Hylands wrote: > > Hi, > > On Thu, Oct 29, 2009 at 4:33 PM, VaibhavGhadiok > <vai...@gm...> wrote: >> >> I see a chip as you have described. For me it says LTNX E3. It seems to >> be >> from LT. >> >> This is to the left of the connector that is used to connect the gumstix >> to >> the Tweener/Robostix. > > I meant on the robostix board. In this photo: > <http://docwiki.gumstix.com/index.php/Robostix_troubleshooting> > It's to the right of the VCC that's in red, and above the V_BATT that's in > red. > > You should be able to test the signals without the gumstix connected. > > When SCL on the robostix side is at 5v, SCL on the gumstix side should > be at 3.3v. > Similarly for SDA. > > When one side is at ground, the other side should be at ground. > > If this looks good, then the problem is almost certainly on the gumstix > itself. > > -- > Dave Hylands > Shuswap, BC, Canada > http://www.DaveHylands.com/ > > ------------------------------------------------------------------------------ > Come build with us! The BlackBerry(R) Developer Conference in SF, CA > is the only developer event you need to attend this year. Jumpstart your > developing skills, take BlackBerry mobile applications to market and stay > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > http://p.sf.net/sfu/devconference > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > -- View this message in context: http://www.nabble.com/Robostix-pin-D.0-%28I2C-SCL%29-doesn%27t-drive-high-%28using-i2c-test%29-tp26104495p26123457.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: Dave H. <dhy...@gm...> - 2009-10-30 01:25:32
|
Hi Vaibhav, On Thu, Oct 29, 2009 at 5:59 PM, VaibhavGhadiok <vai...@gm...> wrote: > > I checked the voltages and they seem to be fine. > > EN is 5V. VCC for the chip is 3.3V. And the SCL, SDA at pin 2,3 are 3.3V and > Pins 6.7 are 5V. Then I think that the problem has to be on the gumstix, unless you can see a solder bridge or something around the pins on the white connector. You should be able to short the 3.3v side to ground and see that the 5v side goes to ground as well. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: VaibhavGhadiok <vai...@gm...> - 2009-10-30 01:59:04
|
I grounded SCL pin on the 3.3V side and I was getting 2.5V (on the 5v side). Should have been getting 0. I grounded the SDA pin on the 3.3 V side and was getting 0.5 V on the corresponding pin on the other side. SCL is the pin that has been giving me problems. Dave Hylands wrote: > > Hi Vaibhav, > > On Thu, Oct 29, 2009 at 5:59 PM, VaibhavGhadiok > <vai...@gm...> wrote: >> >> I checked the voltages and they seem to be fine. >> >> EN is 5V. VCC for the chip is 3.3V. And the SCL, SDA at pin 2,3 are 3.3V >> and >> Pins 6.7 are 5V. > > Then I think that the problem has to be on the gumstix, unless you can > see a solder bridge or something around the pins on the white > connector. > > You should be able to short the 3.3v side to ground and see that the > 5v side goes to ground as well. > > -- > Dave Hylands > Shuswap, BC, Canada > http://www.DaveHylands.com/ > > ------------------------------------------------------------------------------ > Come build with us! The BlackBerry(R) Developer Conference in SF, CA > is the only developer event you need to attend this year. Jumpstart your > developing skills, take BlackBerry mobile applications to market and stay > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > http://p.sf.net/sfu/devconference > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > -- View this message in context: http://www.nabble.com/Robostix-pin-D.0-%28I2C-SCL%29-doesn%27t-drive-high-%28using-i2c-test%29-tp26104495p26123769.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: VaibhavGhadiok <vai...@gm...> - 2009-10-30 02:10:09
|
Just to add. I drove the pin D.0 to low. When I try to pull this using a resistor, it doesn't get pulled up. This is with no gumstix attached. Also on the chip, I get 0 on the SCL on the 3.3 V side and consequently a 0 on the 5V side. For the SDA, I see 3.3 V on the 3.3 V side and 5V on the other side. This is the expected behaviour for this pin. Both SDA and SCL pins are being driven low by me and both are pulled up but only the SDA one is getting pulled up. VaibhavGhadiok wrote: > > I grounded SCL pin on the 3.3V side and I was getting 2.5V (on the 5v > side). Should have been getting 0. > I grounded the SDA pin on the 3.3 V side and was getting 0.5 V on the > corresponding pin on the other side. SCL is the pin that has been giving > me problems. > > > Dave Hylands wrote: >> >> Hi Vaibhav, >> >> On Thu, Oct 29, 2009 at 5:59 PM, VaibhavGhadiok >> <vai...@gm...> wrote: >>> >>> I checked the voltages and they seem to be fine. >>> >>> EN is 5V. VCC for the chip is 3.3V. And the SCL, SDA at pin 2,3 are 3.3V >>> and >>> Pins 6.7 are 5V. >> >> Then I think that the problem has to be on the gumstix, unless you can >> see a solder bridge or something around the pins on the white >> connector. >> >> You should be able to short the 3.3v side to ground and see that the >> 5v side goes to ground as well. >> >> -- >> Dave Hylands >> Shuswap, BC, Canada >> http://www.DaveHylands.com/ >> >> ------------------------------------------------------------------------------ >> Come build with us! The BlackBerry(R) Developer Conference in SF, CA >> is the only developer event you need to attend this year. Jumpstart your >> developing skills, take BlackBerry mobile applications to market and stay >> ahead of the curve. Join us from November 9 - 12, 2009. Register now! >> http://p.sf.net/sfu/devconference >> _______________________________________________ >> gumstix-users mailing list >> gum...@li... >> https://lists.sourceforge.net/lists/listinfo/gumstix-users >> >> > > -- View this message in context: http://www.nabble.com/Robostix-pin-D.0-%28I2C-SCL%29-doesn%27t-drive-high-%28using-i2c-test%29-tp26104495p26123989.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: VaibhavGhadiok <vai...@gm...> - 2009-10-30 03:16:52
|
A small correction to: Also on the chip, I get 0 on the SCL on the 3.3 V side and consequently a 0 on the 5V side. I get 0 on the 5V side and 0.5 V on the 3.3 V side. VaibhavGhadiok wrote: > > Just to add. I drove the pin D.0 to low. When I try to pull this using a > resistor, it doesn't get pulled up. This is with no gumstix attached. > > Also on the chip, I get 0 on the SCL on the 3.3 V side and consequently a > 0 on the 5V side. > For the SDA, I see 3.3 V on the 3.3 V side and 5V on the other side. This > is the expected behaviour for this pin. > > Both SDA and SCL pins are being driven low by me and both are pulled up > but only the SDA one is getting pulled up. > > > VaibhavGhadiok wrote: >> >> I grounded SCL pin on the 3.3V side and I was getting 2.5V (on the 5v >> side). Should have been getting 0. >> I grounded the SDA pin on the 3.3 V side and was getting 0.5 V on the >> corresponding pin on the other side. SCL is the pin that has been giving >> me problems. >> >> >> Dave Hylands wrote: >>> >>> Hi Vaibhav, >>> >>> On Thu, Oct 29, 2009 at 5:59 PM, VaibhavGhadiok >>> <vai...@gm...> wrote: >>>> >>>> I checked the voltages and they seem to be fine. >>>> >>>> EN is 5V. VCC for the chip is 3.3V. And the SCL, SDA at pin 2,3 are >>>> 3.3V and >>>> Pins 6.7 are 5V. >>> >>> Then I think that the problem has to be on the gumstix, unless you can >>> see a solder bridge or something around the pins on the white >>> connector. >>> >>> You should be able to short the 3.3v side to ground and see that the >>> 5v side goes to ground as well. >>> >>> -- >>> Dave Hylands >>> Shuswap, BC, Canada >>> http://www.DaveHylands.com/ >>> >>> ------------------------------------------------------------------------------ >>> Come build with us! The BlackBerry(R) Developer Conference in SF, CA >>> is the only developer event you need to attend this year. Jumpstart your >>> developing skills, take BlackBerry mobile applications to market and >>> stay >>> ahead of the curve. Join us from November 9 - 12, 2009. Register now! >>> http://p.sf.net/sfu/devconference >>> _______________________________________________ >>> gumstix-users mailing list >>> gum...@li... >>> https://lists.sourceforge.net/lists/listinfo/gumstix-users >>> >>> >> >> > > -- View this message in context: http://old.nabble.com/Robostix-pin-D.0-%28I2C-SCL%29-doesn%27t-drive-high-%28using-i2c-test%29-tp26104495p26124399.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: Dave H. <dhy...@gm...> - 2009-10-30 05:12:00
|
Hi Vaibhav, On Thu, Oct 29, 2009 at 8:16 PM, VaibhavGhadiok <vai...@gm...> wrote: > > A small correction to: > Also on the chip, I get 0 on the SCL on the 3.3 V side and consequently a 0 > on the 5V side. > > I get 0 on the 5V side and 0.5 V on the 3.3 V side. So the pullup should have no effect if the line if being driven low or driven high. If the 5v SCL is configured as an input, and you ground the 3.3v side and measure 2.5v on the 5v side, then that suggests that there is a problem with something on the 5v side, most likely a solder bridge or something around the pullup resistors. If the pin is configured as an input, which means that the line is floating, then that's when the pullup kicks in. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: VaibhavGhadiok <vai...@gm...> - 2009-10-31 02:05:30
|
hi Dave My think worked for a while and then stopped. I could cycle through the various states of the SCL pin on the robostix using the i2c-test program on the gumstix. and get the right results. I tried using i2c-load during this time but got the same error that it could not locate 0x0b. Now I am back to square one. Things have stopped working. However, I noticed something interesting. When I run the i2c-test program on the gumstix, my SCL pin does get pulled high. Or for that matter even before starting the program. Essentially the robostix i2c-test program in running on the controller and the first thing it does is to set the robostix SCL, SDA ports as inputs. And then the robostix i2c-test program waits in a while loop, waiting for a character input from the gumstix i2c-test program. And in this state the SCL,SDA should and they do get pulled high to 5V. The problem is when I run the program and start changing things. The robostix i2c-test program essentially changes the states of the robostix pins. It changes between driving high, low and changing to input. When I cycle through these states and again make the SCL pin as input, then it stops being pulled up. In fact even when I change the state to high, the SCL pin goes to 2.5V instead of 5V. Is it something the gumstix side of i2c-test program does that changes things? And yes, if I remove the gumstix and then change the state of the SCL pin to either low, high or input, I get the right results ie 0, 5 and 5 (since it is being pulled up) resp. Everything on the NXP chip is fine, when I ground the 3.3 V side I get a 0.5 V on the 5V side, which I think is fine. This is when I have configured the SCL pin on the Robostix as an input. Thanks Vaibhav -- View this message in context: http://old.nabble.com/Robostix-pin-D.0-%28I2C-SCL%29-doesn%27t-drive-high-%28using-i2c-test%29-tp26104495p26139237.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: VaibhavGhadiok <vai...@gm...> - 2009-10-31 02:14:55
|
On the other hand if I change the i2c-test program on the robostix to drive the pin high by default (initially), before it accepts any input., then I notice that the pin only gets driven to 2.5 V. Maybe the gumstix pins are in some state that cause the voltage to drop. Since I don't do anything to the gumstix side of things. This is without running the gumstix i2c-test program. VaibhavGhadiok wrote: > > hi Dave > > My think worked for a while and then stopped. I could cycle through the > various states of the SCL pin on the robostix using the i2c-test program > on the gumstix. and get the right results. I tried using i2c-load during > this time but got the same error that it could not locate 0x0b. Now I am > back to square one. Things have stopped working. > > However, I noticed something interesting. When I run the i2c-test program > on the gumstix, my SCL pin does get pulled high. Or for that matter even > before starting the program. Essentially the robostix i2c-test program in > running on the controller and the first thing it does is to set the > robostix SCL, SDA ports as inputs. And then the robostix i2c-test program > waits in a while loop, waiting for a character input from the gumstix > i2c-test program. And in this state the SCL,SDA should and they do get > pulled high to 5V. > > The problem is when I run the program and start changing things. The > robostix i2c-test program essentially changes the states of the robostix > pins. It changes between driving high, low and changing to input. When I > cycle through these states and again make the SCL pin as input, then it > stops being pulled up. In fact even when I change the state to high, the > SCL pin goes to 2.5V instead of 5V. Is it something the gumstix side of > i2c-test program does that changes things? > > And yes, if I remove the gumstix and then change the state of the SCL pin > to either low, high or input, I get the right results ie 0, 5 and 5 (since > it is being pulled up) resp. > > Everything on the NXP chip is fine, when I ground the 3.3 V side I get a > 0.5 V on the 5V side, which I think is fine. This is when I have > configured the SCL pin on the Robostix as an input. > > Thanks > > Vaibhav > -- View this message in context: http://old.nabble.com/Robostix-pin-D.0-%28I2C-SCL%29-doesn%27t-drive-high-%28using-i2c-test%29-tp26104495p26139279.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: Dave H. <dhy...@gm...> - 2009-10-31 02:20:17
|
Hi Vaibhav, On Fri, Oct 30, 2009 at 7:14 PM, VaibhavGhadiok <vai...@gm...> wrote: > > On the other hand if I change the i2c-test program on the robostix to drive > the pin high by default (initially), before it accepts any input., then I > notice that the pin only gets driven to 2.5 V. > > Maybe the gumstix pins are in some state that cause the voltage to drop. > Since I don't do anything to the gumstix side of things. This is without > running the gumstix i2c-test program. Just to clarify - you need to make sure that the i2c-pxa and i2c-dev drivers are NOT loaded on the gumstix when using the i2c-test. Otherwise they will see the activity on the SCL and SDA lines and may get confused and may try to drive the lines. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: VaibhavGhadiok <vai...@gm...> - 2009-10-31 02:37:12
|
They are not loaded. Dave Hylands wrote: > > Hi Vaibhav, > > On Fri, Oct 30, 2009 at 7:14 PM, VaibhavGhadiok > <vai...@gm...> wrote: >> >> On the other hand if I change the i2c-test program on the robostix to >> drive >> the pin high by default (initially), before it accepts any input., then I >> notice that the pin only gets driven to 2.5 V. >> >> Maybe the gumstix pins are in some state that cause the voltage to drop. >> Since I don't do anything to the gumstix side of things. This is without >> running the gumstix i2c-test program. > > Just to clarify - you need to make sure that the i2c-pxa and i2c-dev > drivers are NOT loaded on the gumstix when using the i2c-test. > Otherwise they will see the activity on the SCL and SDA lines and may > get confused and may try to drive the lines. > > -- > Dave Hylands > Shuswap, BC, Canada > http://www.DaveHylands.com/ > > ------------------------------------------------------------------------------ > Come build with us! The BlackBerry(R) Developer Conference in SF, CA > is the only developer event you need to attend this year. Jumpstart your > developing skills, take BlackBerry mobile applications to market and stay > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > http://p.sf.net/sfu/devconference > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > -- View this message in context: http://old.nabble.com/Robostix-pin-D.0-%28I2C-SCL%29-doesn%27t-drive-high-%28using-i2c-test%29-tp26104495p26139381.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: VaibhavGhadiok <vai...@gm...> - 2009-10-31 03:04:00
|
Right now, it has again started to work magically but the i2c-load still gives me the same error. VaibhavGhadiok wrote: > > They are not loaded. > > > Dave Hylands wrote: >> >> Hi Vaibhav, >> >> On Fri, Oct 30, 2009 at 7:14 PM, VaibhavGhadiok >> <vai...@gm...> wrote: >>> >>> On the other hand if I change the i2c-test program on the robostix to >>> drive >>> the pin high by default (initially), before it accepts any input., then >>> I >>> notice that the pin only gets driven to 2.5 V. >>> >>> Maybe the gumstix pins are in some state that cause the voltage to drop. >>> Since I don't do anything to the gumstix side of things. This is without >>> running the gumstix i2c-test program. >> >> Just to clarify - you need to make sure that the i2c-pxa and i2c-dev >> drivers are NOT loaded on the gumstix when using the i2c-test. >> Otherwise they will see the activity on the SCL and SDA lines and may >> get confused and may try to drive the lines. >> >> -- >> Dave Hylands >> Shuswap, BC, Canada >> http://www.DaveHylands.com/ >> >> ------------------------------------------------------------------------------ >> Come build with us! The BlackBerry(R) Developer Conference in SF, CA >> is the only developer event you need to attend this year. Jumpstart your >> developing skills, take BlackBerry mobile applications to market and stay >> ahead of the curve. Join us from November 9 - 12, 2009. Register now! >> http://p.sf.net/sfu/devconference >> _______________________________________________ >> gumstix-users mailing list >> gum...@li... >> https://lists.sourceforge.net/lists/listinfo/gumstix-users >> >> > > -- View this message in context: http://old.nabble.com/Robostix-pin-D.0-%28I2C-SCL%29-doesn%27t-drive-high-%28using-i2c-test%29-tp26104495p26139500.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: VaibhavGhadiok <vai...@gm...> - 2009-10-31 03:12:01
|
Also, I tried to load my i2c-io directly on the robostix using uisp. I guess I don't necessarily need the bootloader, however my program on the gumstix still does complain about not being able to access te adc values. Is this a valid approach. Without using the Bootloader. VaibhavGhadiok wrote: > > Right now, it has again started to work magically but the i2c-load still > gives me the same error. > > > > VaibhavGhadiok wrote: >> >> They are not loaded. >> >> >> Dave Hylands wrote: >>> >>> Hi Vaibhav, >>> >>> On Fri, Oct 30, 2009 at 7:14 PM, VaibhavGhadiok >>> <vai...@gm...> wrote: >>>> >>>> On the other hand if I change the i2c-test program on the robostix to >>>> drive >>>> the pin high by default (initially), before it accepts any input., then >>>> I >>>> notice that the pin only gets driven to 2.5 V. >>>> >>>> Maybe the gumstix pins are in some state that cause the voltage to >>>> drop. >>>> Since I don't do anything to the gumstix side of things. This is >>>> without >>>> running the gumstix i2c-test program. >>> >>> Just to clarify - you need to make sure that the i2c-pxa and i2c-dev >>> drivers are NOT loaded on the gumstix when using the i2c-test. >>> Otherwise they will see the activity on the SCL and SDA lines and may >>> get confused and may try to drive the lines. >>> >>> -- >>> Dave Hylands >>> Shuswap, BC, Canada >>> http://www.DaveHylands.com/ >>> >>> ------------------------------------------------------------------------------ >>> Come build with us! The BlackBerry(R) Developer Conference in SF, CA >>> is the only developer event you need to attend this year. Jumpstart your >>> developing skills, take BlackBerry mobile applications to market and >>> stay >>> ahead of the curve. Join us from November 9 - 12, 2009. Register now! >>> http://p.sf.net/sfu/devconference >>> _______________________________________________ >>> gumstix-users mailing list >>> gum...@li... >>> https://lists.sourceforge.net/lists/listinfo/gumstix-users >>> >>> >> >> > > -- View this message in context: http://old.nabble.com/Robostix-pin-D.0-%28I2C-SCL%29-doesn%27t-drive-high-%28using-i2c-test%29-tp26104495p26139521.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: Dave H. <dhy...@gm...> - 2009-10-31 03:14:39
|
Hi Vaibhav, On Fri, Oct 30, 2009 at 8:03 PM, VaibhavGhadiok <vai...@gm...> wrote: > > Right now, it has again started to work magically but the i2c-load still > gives me the same error. And you've reloaded the i2c bootloader? You may also want to check the fuse setting for EESAVE fuse bit. Setting it to 1 will cause the EEPROM to be erased when you program the bootloader. This will ensure that the bootloader uses address 0x0b. Otherwise, if the EEPROM happens to have some old data in it, the bootloader may try to use that as the address rather then 0x0b. The EESAVE is bit 3 of the high fuse byte. So you'd want to change the high fuse bytes from 0xc2 to 0xca. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: VaibhavGhadiok <vai...@gm...> - 2009-10-31 03:29:35
|
Oh my!!! This worked. Can't believe it. Things are working again. Can't thank you enough. I have still no clue why the SCL pin was giving me all this trouble. Right now, I have my i2c-io loaded using i2c-load. Things appear fine so far. So far so good. Should I keep using this setting for the fuse bit. Dave Hylands wrote: > > Hi Vaibhav, > > On Fri, Oct 30, 2009 at 8:03 PM, VaibhavGhadiok > <vai...@gm...> wrote: >> >> Right now, it has again started to work magically but the i2c-load still >> gives me the same error. > > And you've reloaded the i2c bootloader? > > You may also want to check the fuse setting for EESAVE fuse bit. > Setting it to 1 will cause the EEPROM to be erased when you program > the bootloader. This will ensure that the bootloader uses address > 0x0b. Otherwise, if the EEPROM happens to have some old data in it, > the bootloader may try to use that as the address rather then 0x0b. > > The EESAVE is bit 3 of the high fuse byte. So you'd want to change the > high fuse bytes from 0xc2 to 0xca. > > -- > Dave Hylands > Shuswap, BC, Canada > http://www.DaveHylands.com/ > > ------------------------------------------------------------------------------ > Come build with us! The BlackBerry(R) Developer Conference in SF, CA > is the only developer event you need to attend this year. Jumpstart your > developing skills, take BlackBerry mobile applications to market and stay > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > http://p.sf.net/sfu/devconference > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > -- View this message in context: http://old.nabble.com/Robostix-pin-D.0-%28I2C-SCL%29-doesn%27t-drive-high-%28using-i2c-test%29-tp26104495p26139594.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: Dave H. <dhy...@gm...> - 2009-10-31 07:01:06
|
Hi Vaibhav, On Fri, Oct 30, 2009 at 8:29 PM, VaibhavGhadiok <vai...@gm...> wrote: > > Oh my!!! > > This worked. Can't believe it. Things are working again. > > Can't thank you enough. > > I have still no clue why the SCL pin was giving me all this trouble. > > Right now, I have my i2c-io loaded using i2c-load. Yeah - that's the only way it works. i2c-io uses the i2c code that's in the bootloader, so if you try and load i2c-io directly using uisp, then the core i2c code will be missing. > Things appear fine so far. So far so good. > > Should I keep using this setting for the fuse bit Either setting is fine, as long as you're aware of the differences. Sometimes I use one setting, sometimes I use the other. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |