From: Dave H. <dhy...@gm...> - 2006-11-10 09:00:21
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HI Chris, > For this one, I used ONLY the connex and tweener boards. When I first ran > i2c-test, I saw: > > gumstix: SCL: 1 SDA: 1 > > And connecting SCL to Vcc didn't change that. No - it wouldn't since SCL is already at 1. Try alternating back and forth, connecting SCL to Gnd and then to Vcc. If SCL reads 0 when connected to ground and 1 when connected to Vcc, then the wires are connected through the gumstix fine. The later gumstixs have a weak pullup on the gumstix itself, which explains it going high when not connected to the robostix. I looked at the robostix layout and I don't see any place obvious that the SCL line could be shorted out with ground, although there is a possibility that it's shorted out with L_DD14, which is the active low enable for the '245. So here's another test to check for that. Assemble your stack of boards together. Run i2c-test, you should be back at the situation where SCL is 0 on the gumstix side of things. Now try: modprobe proc_gpio echo "GPIO out set" > /proc/gpio/GPIO72 If the SCL line changes to 1, then do: echo "GPIO out clear" > /proc/gpio/GPIO72 and if that makes it go back to zero, then this indicates that there is a short between the SCL and LDD14, which are right next to each other on the pullup resistor pack (U$62). These two pins are towards the center of the board, and are the 2nd and 3rd pins if start counting on the side closest to the hirose connector. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: Chris E. <roo...@gm...> - 2006-11-10 15:28:30
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The saga continues... If SCL reads 0 when connected to ground and 1 when connected to Vcc, > then the wires are connected through the gumstix fine. The later > gumstixs have a weak pullup on the gumstix itself, which explains it > going high when not connected to the robostix. Okay, everything is fine here. I looked at the robostix layout and I don't see any place obvious that > the SCL line could be shorted out with ground, although there is a > possibility that it's shorted out with L_DD14, which is the active low > enable for the '245. > > So here's another test to check for that. Assemble your stack of > boards together. Run i2c-test, you should be back at the situation > where SCL is 0 on the gumstix side of things. > > Now try: > > modprobe proc_gpio > echo "GPIO out set" > /proc/gpio/GPIO72 > > If the SCL line changes to 1, then do: > > echo "GPIO out clear" > /proc/gpio/GPIO72 Nope- setting GPIO72 gave SCL: 0 |
From: Dave H. <dhy...@gm...> - 2006-11-10 16:42:37
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Hi Chris, > > echo "GPIO out set" > /proc/gpio/GPIO72 > > > > If the SCL line changes to 1, then do: > > > > echo "GPIO out clear" > /proc/gpio/GPIO72 > > Nope- setting GPIO72 gave SCL: 0 OK - so it looks like the gumstix is fine, but the robostix has some type of connectivity issues somewhere between the hirose and ATMega128. I put up a photo which identifies all of the spots that the SCL line shows up on the robostix. If you power up the robostix all by itself, you should measure 5v in the following spots: 1 - Pin 25 on the ATMega128 (I put 17 & 32 as references for counting). Pin 25 has a short little trace running from it that drops into a via. 2 - Pin 16 on the UARTs connector. 3 - Pin 7 on the 9515 chip. 4 - The spot labelled "2nd from the right", which is the +5v pullup for SCL. The following spots should measure 3.3v: 1 - Pin 2 on the 9515 chip. 2 - The 2nd from the right on the U$62 chip. This is the +3.3v pullup for SCL. 3 - Pin 20 on the hirose connector (pin 30 in in the top left of the connector). I higlighted the trace which connectst to pin 20. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: Chris E. <roo...@gm...> - 2006-11-10 21:18:54
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Hey Dave, 1 - Pin 25 on the ATMega128 (I put 17 & 32 as references for > counting). Pin 25 has a short little trace running from it that drops > into a via. 1.27v 2 - Pin 16 on the UARTs connector. 1.27v > 3 - Pin 7 on the 9515 chip. 1.04v 4 - The spot labelled "2nd from the right", which is the +5v pullup for SCL. 5.0v The following spots should measure 3.3v: > > 1 - Pin 2 on the 9515 chip. 0.52v 2 - The 2nd from the right on the U$62 chip. This is the +3.3v pullup for > SCL. 0.52v 3 - Pin 20 on the hirose connector (pin 30 in in the top left of the > connector). I higlighted the trace which connectst to pin 20. 0.52v I'm new to a lot of this, so it's possible I did something wrong. I connected the black lead on the multimeter to MOTOR ground, and the red lead to the pin in question. Is there something wrong with the voltage regulator? Why am I seeing the correct voltage for the SCL pullup and not for anything else? By the way, thanks for walking me through this. |
From: Dave H. <dhy...@gm...> - 2006-11-10 22:08:20
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Hi Chris, > I'm new to a lot of this, so it's possible I did something wrong. I > connected the black lead on the multimeter to MOTOR ground, and the red lead > to the pin in question. That's correct. You need to be careful that your probe is only touching one pin, but based on your readings that seems to be the case. > Is there something wrong with the voltage regulator? > Why am I seeing the correct voltage for the SCL pullup and not for anything > else? There is definitely something fishy going on. I'm also suspecting more than one problem. I see I forgot the link to the photo: http://davehylands.com/gumstix-wiki/i2c/Robostix-SCL.jpg (but obviously you found it) Some additional places to check: 1 - Right next to the "Pin 7" is Pin 8 (on the 9515). It should have 3.3v on it. 2 - Following the fat trace coming off of pin 8 and heading left is a 5 pin voltage regulator. Pin 5 (top left as seen in the photo) is the output from the 3.3v voltage regualtor. It should be 3.3v. 3 - Pins 1 and 3 of the 3.3v voltage regulator (bottom left and bottom right) should be at around 5v (the same as the power jack). There are 3 other voltage regulators on the board. Each is an 8-pin 5219. U$59 is to the left of the ATMega128. U$60 is the upper one closest to the ATMega128 on the right hand side and U$50 is the one below and to the right of U$60. Each of these chips has a little dot in one corner. This indicates pin 1, and pins 1 thru 4 are on the same side of the chip. When the gumstix is not plugged in, then Pin 1 (enable) of all of them should be around 3.3v (actualy U$50 pin 1 should be around 5v). Pin 3 (output) of all of them should be at 5v. If the enables are low, then the outputs won't be at 5v. The enables of U$59 and U$60 are pulled up to 3.3v by the U$62 resistor pack (close to the hirose connector). If for some reason the 3.3v regulator isn't working, then that might explain some things. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: Andrei R. <ar...@ya...> - 2006-11-12 20:43:03
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Hi, looking at the picture in http://docwiki.gumstix.org/Robostix_gumstix_ISP it appears that jumpers on robostix UARTS connector short pins 1-4 and 5-8, which are V_BATT--ATM_RX0 and IR_RXD_5--V_BATT respectively. Doesn't make sense. Am I wrong or what's the deal there ? -Andrei. |
From: Dave H. <dhy...@gm...> - 2006-11-12 22:31:48
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Hi Andrei, > looking at the picture in > http://docwiki.gumstix.org/Robostix_gumstix_ISP > it appears that jumpers on robostix UARTS connector > short pins 1-4 and 5-8, which are > V_BATT--ATM_RX0 and IR_RXD_5--V_BATT respectively. > Doesn't make sense. Am I wrong or what's > the deal there ? How are you counting the pins? Or rather what are you using that makes you think that Pin 1 is V_BATT? If you look at this page: <http://docwiki.gumstix.org/Robostix_I/O_pins#UARTS> Pin 1 is STUART-Rxd and Pin 4 is ATM_TxD Pin 5 is STUART-Txd and Pin 8 is ATM_Rxd The silkscreen on the back of the board agrees with this as well -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: Andrei R. <ar...@ya...> - 2006-11-12 22:49:52
Attachments:
uarts-old.jpg
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Or crap, I was using robostix schematics printed about a year ago. It was incorrect then and incorrect still. I'm not making it up - see attached scan picture. Thanks, Dave. --- Dave Hylands <dhy...@gm...> wrote: > Hi Andrei, > > > looking at the picture in > > http://docwiki.gumstix.org/Robostix_gumstix_ISP > > it appears that jumpers on robostix UARTS > connector > > short pins 1-4 and 5-8, which are > > V_BATT--ATM_RX0 and IR_RXD_5--V_BATT respectively. > > Doesn't make sense. Am I wrong or what's > > the deal there ? > > How are you counting the pins? Or rather what are > you using that makes > you think that Pin 1 is V_BATT? > > If you look at this page: > <http://docwiki.gumstix.org/Robostix_I/O_pins#UARTS> > > Pin 1 is STUART-Rxd and Pin 4 is ATM_TxD > Pin 5 is STUART-Txd and Pin 8 is ATM_Rxd > > The silkscreen on the back of the board agrees with > this as well > > -- > Dave Hylands > Vancouver, BC, Canada > http://www.DaveHylands.com/ > > ------------------------------------------------------------------------- > Using Tomcat but need to do more? Need to support > web services, security? > Get stuff done quickly with pre-integrated > technology to make your job easier > Download IBM WebSphere Application Server v.1.0.1 > based on Apache Geronimo > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > |
From: Michal 'L. Z. <la...@fa...> - 2006-11-12 23:10:04
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Hi, Where can I find schematic for the tweener board? I really need to be sure for the cut that I described on the page, before I made it. Thanks, Michal Zygmunt |
From: Michal 'L. Z. <la...@fa...> - 2006-11-12 23:11:12
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Nevermind;) I have just found it:) Thanks, Michal Zygmunt -----Original Message----- From: gum...@li... [mailto:gum...@li...] On Behalf Of Michal 'LaHcIm' Zygmunt Sent: Monday, November 13, 2006 12:03 AM To: 'General mailing list for gumstix users.' Subject: [Gumstix-users] Tweener schematic needed Hi, Where can I find schematic for the tweener board? I really need to be sure for the cut that I described on the page, before I made it. Thanks, Michal Zygmunt ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ gumstix-users mailing list gum...@li... https://lists.sourceforge.net/lists/listinfo/gumstix-users |
From: Dave H. <dhy...@gm...> - 2006-11-13 00:39:48
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Hi Andrei, On 11/12/06, Andrei Rylin <ar...@ya...> wrote: > Or crap, I was using robostix schematics printed > about a year ago. It was incorrect then > and incorrect still. I'm not making it up - > see attached scan picture. Yeah - the schematics posted were incorrect. None of the robostix actually made followed that (except maybe the prototype). -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: Chris E. <roo...@gm...> - 2006-11-10 22:59:28
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Hey Dave, 1 - Right next to the "Pin 7" is Pin 8 (on the 9515). It should have 3.3v on > it. 3.26v 2 - Following the fat trace coming off of pin 8 and heading left is a > 5 pin voltage regulator. Pin 5 (top left as seen in the photo) is the > output from the 3.3v voltage regualtor. It should be 3.3v. 3.26v 3 - Pins 1 and 3 of the 3.3v voltage regulator (bottom left and bottom > right) should be at around 5v (the same as the power jack). Both 5.16v There are 3 other voltage regulators on the board. Each is an 8-pin > 5219. U$59 is to the left of the ATMega128. U$60 is the upper one > closest to the ATMega128 on the right hand side and U$50 is the one > below and to the right of U$60. Each of these chips has a little dot in one corner. This indicates pin > 1, and pins 1 thru 4 are on the same side of the chip. > > When the gumstix is not plugged in, then > > Pin 1 (enable) of all of them should be around 3.3v (actualy U$50 pin > 1 should be around 5v). > Pin 3 (output) of all of them should be at 5v. U$50 1 - 5.16v 3 - 5.00v U$59 1 - 3.05v 3 - 4.97v U$60 1 - 3.05v 3 - 4.96 So the voltage regulators are okay? |
From: Dave H. <dhy...@gm...> - 2006-11-10 23:35:19
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Hi Chris, > So the voltage regulators are okay? Yep - everything looks good on that front. Lets do a continuity test. Robostix powered off, and on its own. Pin 25 on the ATMega128, UART pin 16, Pin 7 on the 9515 and the spot labelled "second from the right" should all be connected to each other. Based on your previous results, you measured: Pin 25 on the ATMega as 1.27v UART Pin 16 as 1.27v Pin 7 on the 9515 chip as 1.04v and the the spot labelled "2nd from the right" as 5v. I suspect you'll find that ATMega128 pin 17, UART pin 16, and 9515 pin 7 are all connected to each other, but the pullup isn't. This would support the voltages that you're seeing. What that means is that the pullup is probably got a bad contact with the pad underneth it, or the via is flawed. The good news, is if this is the case, you can probably just provide your own 10k pullup resistor between UART pin 16, and one of the +5 pins on the UARTS connector (pin 3, 6, 11, or 14). Once you've added the resistor, you can should go back and repeat all of the measurements from the email earlier this morning, where you were getting 1.27v, 1.27v, etc. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: Chris E. <roo...@gm...> - 2006-11-11 00:45:01
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Hey Dave, I suspect you'll find that ATMega128 pin 17, UART pin 16, and 9515 pin > 7 are all connected to each other, but the pullup isn't. I'm assuming you meant ATMega128 pin 25. They are all connected, but the pullup appears to have been soldered poorly. I'm pretty sure it is a bad connection. The good news, is if this is the case, you can probably just provide > your own 10k pullup resistor between UART pin 16, and one of the +5 > pins on the UARTS connector (pin 3, 6, 11, or 14). > > Once you've added the resistor, you can should go back and repeat all > of the measurements from the email earlier this morning, where you > were getting 1.27v, 1.27v, etc. Yep- after adding the resistor between UARTS pins 14 and 16, I'm getting the correct voltages. i2c-test now shows: gumstix: SCL: 1 SDA: 1 robostix: SCLw: 1 SCLr: 1 SDAw: 1 SDAr: 1 DDRD: 0 PIND: 3 I installed i2c-bootloader again and I was able to load i2c-io. The examples on the i2c-io wiki page worked! Thanks so much for all of your help. If I were to try and resolder the pins on the onboard pullup, do I have a high risk of overheating nearby components? Is this something I should attempt? |
From: Dave H. <dhy...@gm...> - 2006-11-11 03:04:50
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Hi Chris, > I installed i2c-bootloader again and I was able to load i2c-io. The examples > on the i2c-io wiki page worked! Thanks so much for all of your help. > > If I were to try and resolder the pins on the onboard pullup, do I have a > high risk of overheating nearby components? Is this something I should > attempt? It depends on whether you have headers installed or not. With the headers, it's really hard to even get the proper angle to do any soldering. Even with easy access, the resistor pads are really small. If you haven't worked with soldering stuff that small before, and don't have the right tools (fine tipped soldering iron, solder braid, liquid flux, fine solder), then I don't think I would attempt it. To do it completely properly you should remove the entire resistor chip, clean things up and resolder. Removing the xexisting part requires the use of a hot air gun, or something like ChipQuik. If you have a soldering iron with a small tip, you could try just heating the pin up for a few seconds (without adding any solder) to try and melt any unmelted solder paste that might be under the chip. Adding solder can make things worst if you don't have a way of removing the solder bridges. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |