From: Dustin W. <dus...@ya...> - 2009-08-12 19:40:30
|
I have written a program that runs on the robostix that monitors the A/D channels. I have it setup such that I can connected to the robostix from my computer via a MAX232. Now I want to replace my computer with a Gumstix Verdex. However when I attach my Robostix to my Verdex I am unable to communicate with the Robostix. I have connected UART-0 on the Robostix to the FFUART on the Verdex. I have even tried keeping the two boards separate and using a ConsoleLCD18-vx to bridge the gap with no luck. Can anyone explain to me how to get serial communication to work between the Verdex and Robostix or point me to documentation? I have tried to find documentation on the Wikis but that has been fruitless. Thanks in advance, Dustin Webb |
From: Dave H. <dhy...@gm...> - 2009-08-12 20:29:07
|
Hi Dustin, On Wed, Aug 12, 2009 at 12:13 PM, Dustin Webb<dus...@ya...> wrote: > I have written a program that runs on the robostix that monitors the A/D > channels. I have it setup such that I can connected to the robostix from my > computer via a MAX232. Now I want to replace my computer with a Gumstix > Verdex. However when I attach my Robostix to my Verdex I am unable to > communicate with the Robostix. I have connected UART-0 on the Robostix to > the FFUART on the Verdex. I have even tried keeping the two boards separate > and using a ConsoleLCD18-vx to bridge the gap with no luck. Can anyone > explain to me how to get serial communication to work between the Verdex and > Robostix or point me to documentation? I have tried to find documentation on > the Wikis but that has been fruitless. If you build a little jumper block, like the one with two yellow wires in the first picture of this page: <http://docwiki.gumstix.com/index.php/Robostix_gumstix_ISP> then that will connect UART-0 on the robostix to the STUART port on the gumstix. The Flash-LED program on this page: <http://docwiki.gumstix.com/index.php/Robostix_samples> writes to both UART ports on the robostix. You can use the sertest program on the gumstix at 38400 baud to read the data (that's the baud rate that Flash-LED uses). http://www.davehylands.com/gumstix-wiki/wikifiles/sertest/ (originally from over here: <http://docwiki.gumstix.com/index.php/Sample_code/C/Serial> -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: Dustin W. <dus...@ya...> - 2009-08-13 00:40:36
|
Hi Dave: > If you build a little jumper block I'm using a cable but it has the same basic configuration. > then that will connect UART-0 on the robostix to the STUART port on the gumstix. Is it required that I connect the Verdex to the Robostix via the STUART or can I use the FFUART? This is really just intellectual curiosity. I have no problem using the STUART instead of the FFUART so long as I can use the FFUART to communicate with my SSC-32. I believe this is possible but I'll have to test it to be sure. > The Flash-LED program on this page > You can use the sertest program on the gumstix at 38400 baud to read the data Got them and compiled them successfully and in the case of the Flash-LED I had no problem loading it onto the Robostix. Now this is where it gets interesting. I notice that if I do not connect the two boards the LEDs on the Robostix flash. If I connect the two boards then the LEDs on the Robostix do not flash if I apply power through the barrel connector on the Robostix. They do flash though if I apply power through the BOARD port on the Robostix however in this configuration the Verdex does not power up. Needless to say, when the Verdex does power up I get nothing from the Robostix via sertest. Now for a little history. I have revision 1131 of the Robostix. As such, since I wanted to develop my program without the Verdex inline, I installed a pullup resistor in accordance with the Robostix Modifications page <http://docwiki.gumstix.org/index.php/Robostix_modifications#Pullup_Resistor_.28applies_to_all_revisions_-_upto_and_including_1131.29>. However this was not enough to get my Robostix working without the Verdex. I also had to install a jumper between pin 6 on the UARTs header and +5V on the BOARD connector. I found this fix on the mailing list though I cannot recall where exactly. Suffice it to say it worked. At this point I am wondering if one or both of these modifications are problematic. The documentation you have already compiled has proven quite useful and I want to thank you for that. With that said any additional help you can provide would be highly appreciated. I am quickly approaching my deadline for this project and this is one of the last tasks I must perform to complete it. Thanks kindly, Dustin Webb ________________________________ From: Dave Hylands <dhy...@gm...> To: General mailing list for gumstix users. <gum...@li...> Sent: Wednesday, August 12, 2009 2:28:55 PM Subject: Re: [Gumstix-users] Gumstix, Robostix, and Serial Communication Hi Dustin, On Wed, Aug 12, 2009 at 12:13 PM, Dustin Webb<dus...@ya...> wrote: > I have written a program that runs on the robostix that monitors the A/D > channels. I have it setup such that I can connected to the robostix from my > computer via a MAX232. Now I want to replace my computer with a Gumstix > Verdex. However when I attach my Robostix to my Verdex I am unable to > communicate with the Robostix. I have connected UART-0 on the Robostix to > the FFUART on the Verdex. I have even tried keeping the two boards separate > and using a ConsoleLCD18-vx to bridge the gap with no luck. Can anyone > explain to me how to get serial communication to work between the Verdex and > Robostix or point me to documentation? I have tried to find documentation on > the Wikis but that has been fruitless. If you build a little jumper block, like the one with two yellow wires in the first picture of this page: <http://docwiki.gumstix.com/index.php/Robostix_gumstix_ISP> then that will connect UART-0 on the robostix to the STUART port on the gumstix. The Flash-LED program on this page: <http://docwiki.gumstix.com/index.php/Robostix_samples> writes to both UART ports on the robostix. You can use the sertest program on the gumstix at 38400 baud to read the data (that's the baud rate that Flash-LED uses). http://www.davehylands.com/gumstix-wiki/wikifiles/sertest/ (originally from over here: <http://docwiki.gumstix.com/index.php/Sample_code/C/Serial> -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ gumstix-users mailing list gum...@li... https://lists.sourceforge.net/lists/listinfo/gumstix-users |
From: Dave H. <dhy...@gm...> - 2009-08-13 02:02:44
|
Hi Dustin, On Wed, Aug 12, 2009 at 5:40 PM, Dustin Webb<dus...@ya...> wrote: > Hi Dave: > >> If you build a little jumper block > I'm using a cable but it has the same basic configuration. > >> then that will connect UART-0 on the robostix to the STUART port on the >> gumstix. > > Is it required that I connect the Verdex to the Robostix via the STUART or > can I use the FFUART? This is really just intellectual curiosity. I have no > problem using the STUART instead of the FFUART so long as I can use the > FFUART to communicate with my SSC-32. I believe this is possible but I'll > have to test it to be sure. The FFUART is the linux console, so all of the bootup messages will be sent to the robostix. No reason why you can't use it, you just need to be aware of what's going where. >> The Flash-LED program on this page >> You can use the sertest program on the gumstix at 38400 baud to read the >> data > > Got them and compiled them successfully and in the case of the Flash-LED I > had no problem loading it onto the Robostix. Now this is where it gets > interesting. I notice that if I do not connect the two boards the LEDs on > the Robostix flash. If I connect the two boards then the LEDs on the > Robostix do not flash if I apply power through the barrel connector on the > Robostix. They do flash though if I apply power through the BOARD port on > the Robostix however in this configuration the Verdex does not power up. > Needless to say, when the Verdex does power up I get nothing from the > Robostix via sertest. When you power up the robostix and the verdex together, then the robostix gets held in reset. Supplying power through the barrel jack will power both the gumstix and the verdex. There are a number of things that you can do on the verdex to get the robostix running, depending on how quickly you want it to start running. I cover the basic approaches on this page: <http://docwiki.gumstix.com/index.php/Robostix_power> > Now for a little history. I have revision 1131 of the Robostix. As such, > since I wanted to develop my program without the Verdex inline, I installed > a pullup resistor in accordance with the Robostix Modifications page > <http://docwiki.gumstix.org/index.php/Robostix_modifications#Pullup_Resistor_.28applies_to_all_revisions_-_upto_and_including_1131.29>. > However this was not enough to get my Robostix working without the Verdex. I > also had to install a jumper between pin 6 on the UARTs header and +5V on > the BOARD connector. I found this fix on the mailing list though I cannot > recall where exactly. Suffice it to say it worked. At this point I am > wondering if one or both of these modifications are problematic. You probably saw it on this page: <http://docwiki.gumstix.com/index.php/Robostix_modifications> > The documentation you have already compiled has proven quite useful and I > want to thank you for that. With that said any additional help you can > provide would be highly appreciated. I am quickly approaching my deadline > for this project and this is one of the last tasks I must perform to > complete it. Hopefully, the above links will prove useful. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: Dustin W. <dus...@ya...> - 2009-08-13 04:04:06
|
Hello again Dave, > The FFUART is the linux console, so all of the bootup messages will be > sent to the robostix. No reason why you can't use it, you just need to > be aware of what's going where. Good to know, this will definitely impact my plans. > When you power up the robostix and the verdex together, then the > robostix gets held in reset. That was precisely the problem. I am not only able to retrieve the data form Flash-LED with sertest but my programs work too! > Supplying power through the barrel jack will power both the gumstix > and the verdex. Does this mean I cannot power the boards using the BOARD connector? > Hopefully, the above links will prove useful. Yes, yes they did. Thanks again, Dustin Webb ________________________________ From: Dave Hylands <dhy...@gm...> To: General mailing list for gumstix users. <gum...@li...> Sent: Wednesday, August 12, 2009 8:02:33 PM Subject: Re: [Gumstix-users] Gumstix, Robostix, and Serial Communication Hi Dustin, On Wed, Aug 12, 2009 at 5:40 PM, Dustin Webb<dus...@ya...> wrote: > Hi Dave: > >> If you build a little jumper block > I'm using a cable but it has the same basic configuration. > >> then that will connect UART-0 on the robostix to the STUART port on the >> gumstix. > > Is it required that I connect the Verdex to the Robostix via the STUART or > can I use the FFUART? This is really just intellectual curiosity. I have no > problem using the STUART instead of the FFUART so long as I can use the > FFUART to communicate with my SSC-32. I believe this is possible but I'll > have to test it to be sure. The FFUART is the linux console, so all of the bootup messages will be sent to the robostix. No reason why you can't use it, you just need to be aware of what's going where. >> The Flash-LED program on this page >> You can use the sertest program on the gumstix at 38400 baud to read the >> data > > Got them and compiled them successfully and in the case of the Flash-LED I > had no problem loading it onto the Robostix. Now this is where it gets > interesting. I notice that if I do not connect the two boards the LEDs on > the Robostix flash. If I connect the two boards then the LEDs on the > Robostix do not flash if I apply power through the barrel connector on the > Robostix. They do flash though if I apply power through the BOARD port on > the Robostix however in this configuration the Verdex does not power up. > Needless to say, when the Verdex does power up I get nothing from the > Robostix via sertest. When you power up the robostix and the verdex together, then the robostix gets held in reset. Supplying power through the barrel jack will power both the gumstix and the verdex. There are a number of things that you can do on the verdex to get the robostix running, depending on how quickly you want it to start running. I cover the basic approaches on this page: <http://docwiki.gumstix.com/index.php/Robostix_power> > Now for a little history. I have revision 1131 of the Robostix. As such, > since I wanted to develop my program without the Verdex inline, I installed > a pullup resistor in accordance with the Robostix Modifications page > <http://docwiki.gumstix.org/index.php/Robostix_modifications#Pullup_Resistor_.28applies_to_all_revisions_-_upto_and_including_1131.29>. > However this was not enough to get my Robostix working without the Verdex. I > also had to install a jumper between pin 6 on the UARTs header and +5V on > the BOARD connector. I found this fix on the mailing list though I cannot > recall where exactly. Suffice it to say it worked. At this point I am > wondering if one or both of these modifications are problematic. You probably saw it on this page: <http://docwiki.gumstix.com/index.php/Robostix_modifications> > The documentation you have already compiled has proven quite useful and I > want to thank you for that. With that said any additional help you can > provide would be highly appreciated. I am quickly approaching my deadline > for this project and this is one of the last tasks I must perform to > complete it. Hopefully, the above links will prove useful. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ gumstix-users mailing list gum...@li... https://lists.sourceforge.net/lists/listinfo/gumstix-users __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com |
From: Dave H. <dhy...@gm...> - 2009-08-13 05:56:24
|
Hi Dustin, >> Supplying power through the barrel jack will power both the gumstix >> and the verdex. > > Does this mean I cannot power the boards using the BOARD connector? You should be able to. The barrel jack switches the GND signal. So the GND from the BOARD connector goes through the barrel jack. When a plug is inserted, then the ground from BOARD is disconnected from the board GND. When you remove the jack, it should connect the BOARD GND through to the robostix GND. You should be able to test this with a multimeter. It's possible that your jack isn't working properly. If it turns out that your jack isn't working, you could solder a wire from pin 1 to pin 2 (the two pins on the sides. This should make the BOARD connector work properly. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: Dustin W. <dus...@ya...> - 2009-08-15 19:38:05
|
Hi Dave: > You should be able to. The barrel jack switches the GND signal. So the > GND from the BOARD connector goes through the barrel jack. When a plug > is inserted, then the ground from BOARD is disconnected from the board > GND. > When you remove the jack, it should connect the BOARD GND through to > the robostix GND. You should be able to test this with a multimeter. > It's possible that your jack isn't working properly. > If it turns out that your jack isn't working, you could solder a wire > from pin 1 to pin 2 (the two pins on the sides. This should make the > BOARD connector work properly. I'm just getting back to this issue. I have to admit I don't completely follow what you are saying. However I took my multimeter to the board anyway to gain a better understanding of what's going on. What I found is that there are 3 terminals on the barrel itself. Two on the sides which appear to be connected when the plug is not inserted and disconnected otherwise. Both of these terminals are attached to the ground terminal on the BOARD and MOTOR headers when the plug is not inserted. When the plug is inserted the left terminal is connected to the ground terminal on the BOARD header while the right terminal is connected to the ground terminal on the MOTOR header. The terminal on the barrel connector, the one coming out from the back, is connected to the +5V on both the BOARD and MOTOR headers regardless of whether the plug has been inserted. Ultimately I want to power the board from a 5 cell 6V NiMH. Hi have tried connecting power to the BOARD and MOTOR headers, though not simultaneously because I didn't think that would be beneficial. From that I have found that if I don't have the Verdex attached then I can power the Robostix via the MOTOR header. If I do have the Verdex attached then I am unable to power either the Robostix or the Verdex through either connector. With all that said could you help me understand how to achieve my goal? Thanks again, Dustin Webb |
From: Dave H. <dhy...@gm...> - 2009-08-15 20:29:51
|
Hi Dustin, On Sat, Aug 15, 2009 at 12:37 PM, Dustin Webb<dus...@ya...> wrote: > Hi Dave: > >> You should be able to. The barrel jack switches the GND signal. So the >> GND from the BOARD connector goes through the barrel jack. When a plug >> is inserted, then the ground from BOARD is disconnected from the board >> GND. > >> When you remove the jack, it should connect the BOARD GND through to >> the robostix GND. You should be able to test this with a multimeter. >> It's possible that your jack isn't working properly. > >> If it turns out that your jack isn't working, you could solder a wire >> from pin 1 to pin 2 (the two pins on the sides. This should make the >> BOARD connector work properly. > > I'm just getting back to this issue. I have to admit I don't completely > follow what you are saying. However I took my multimeter to the board anyway > to gain a better understanding of what's going on. What I found is that > there are 3 terminals on the barrel itself. Two on the sides which appear to > be connected when the plug is not inserted and disconnected otherwise. Both > of these terminals are attached to the ground terminal on the BOARD and > MOTOR headers when the plug is not inserted. When the plug is inserted the > left terminal is connected to the ground terminal on the BOARD header while > the right terminal is connected to the ground terminal on the MOTOR header. > The terminal on the barrel connector, the one coming out from the back, is > connected to the +5V on both the BOARD and MOTOR headers regardless of > whether the plug has been inserted. So that all sounds correct. > Ultimately I want to power the board from a 5 cell 6V NiMH. Hi have tried > connecting power to the BOARD and MOTOR headers, though not simultaneously > because I didn't think that would be beneficial. From that I have found that > if I don't have the Verdex attached then I can power the Robostix via the > MOTOR header. If I do have the Verdex attached then I am unable to power > either the Robostix or the Verdex through either connector. With all that > said could you help me understand how to achieve my goal? Make sure your batteries are fully charged, and that you have minus connected to ground and plus connected to BOARD +5. Other than that it should work. The only other thing to try is to connect your battery between +5 on the BOARD connector and GND someplace else. It might be that the barrel jack is not getting a good ground though between the BOARD connector and GND. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: Dustin W. <dus...@ya...> - 2009-08-16 04:40:08
|
Aloha Dave: > Make sure your batteries are fully charged, and that you have minus > connected to ground and plus connected to BOARD +5. The connections are correct and battery fully charged. However my experiments haven't involved my battery. I have interfaced a circuit of my own design with the Verdex/Robostix stack. As such I have built my own voltage regulator and am using it to supply power to the Verdex/Robostix. I have been assuming that I could get this working and then replace the AC source a battery. It seems though that when I connect my battery to BOARD it everything works as desired! So the question becomes, can I draw power from the stack instead of applying power to it? For instance, can I attach my battery to the BOARD header and then connect my circuit to the MOTOR header to supply it power? Seems like I should be able to but I plan on testing it. Once again I appreciate the tips. Dustin Webb |
From: Dave H. <dhy...@gm...> - 2009-08-16 05:28:36
|
Hi Dustin, On Sat, Aug 15, 2009 at 9:39 PM, Dustin Webb<dus...@ya...> wrote: > Aloha Dave: > >> Make sure your batteries are fully charged, and that you have minus >> connected to ground and plus connected to BOARD +5. > > The connections are correct and battery fully charged. However my > experiments haven't involved my battery. I have interfaced a circuit of my > own design with the Verdex/Robostix stack. As such I have built my own > voltage regulator and am using it to supply power to the Verdex/Robostix. Then the next thing is to make sure that your voltage regulator can deliver enough current. It should be capable of delivering 1A to be comparable to the wall-wart. You might get by with half an amp under the right circumstances Sparkfun just came out with a nice little DC-DC converter module: <http://www.sparkfun.com/commerce/product_info.php?products_id=9275> These are much more efficient than linear regulators, and you'll also get more battery life. > I > have been assuming that I could get this working and then replace the AC > source a battery. It seems though that when I connect my battery to BOARD it > everything works as desired! So the question becomes, can I draw power from > the stack instead of applying power to it? For instance, can I attach my > battery to the BOARD header and then connect my circuit to the MOTOR header > to supply it power? Seems like I should be able to but I plan on testing it. Yeah - that should work fine. BOARD and V_MOTOR are connected in parallel by default. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: Kirk M. <km...@ec...> - 2009-08-16 11:40:15
|
hi - sorry I couldn't find much on the forum archive - but Has anyone managed to use Standby mode OK from OE on the Overo? We're about to try switching from connex at last and if standby works we can make use of it.... cheers! Kirk Martinez University of Southampton http://users.ecs.soton.ac.uk/km/projs/gumstix/gumsense.html |
From: Dustin W. <dus...@ya...> - 2009-08-16 15:22:04
|
Good Morning Dave: > Sparkfun just came out with a nice little DC-DC converter module: > <http://www.sparkfun.com/commerce/product_info.php?products_id=9275> > These are much more efficient than linear regulators, and you'll also > get more battery life. It just so happens that I picked up the components for my power supply circuit from sparkfun <http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=57>, <http://www.sparkfun.com/commerce/product_info.php?products_id=8373> and learned how to build it from their tutorial <http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=57>. Reviewing the components of the circuit it seems it should be able to supply enough current. > Yeah - that should work fine. BOARD and V_MOTOR are connected in > parallel by default. When I burnt the trace on my Robostix lastnight I was trying to determine whether the power coming from V_MOTOR was regulated. I suspect not but I wanted to be certain. Do you happen to know? Also is it safe to connect the battery (5 Cell 6V NiMH) directly to the Robostix or must I regulate it first? Thanks, Dustin Webb ________________________________ From: Dave Hylands <dhy...@gm...> To: General mailing list for gumstix users. <gum...@li...> Sent: Saturday, August 15, 2009 11:28:26 PM Subject: Re: [Gumstix-users] Gumstix, Robostix, and Serial Communication Hi Dustin, On Sat, Aug 15, 2009 at 9:39 PM, Dustin Webb<dus...@ya...> wrote: > Aloha Dave: > >> Make sure your batteries are fully charged, and that you have minus >> connected to ground and plus connected to BOARD +5. > > The connections are correct and battery fully charged. However my > experiments haven't involved my battery. I have interfaced a circuit of my > own design with the Verdex/Robostix stack. As such I have built my own > voltage regulator and am using it to supply power to the Verdex/Robostix. Then the next thing is to make sure that your voltage regulator can deliver enough current. It should be capable of delivering 1A to be comparable to the wall-wart. You might get by with half an amp under the right circumstances Sparkfun just came out with a nice little DC-DC converter module: <http://www.sparkfun.com/commerce/product_info.php?products_id=9275> These are much more efficient than linear regulators, and you'll also get more battery life. > I > have been assuming that I could get this working and then replace the AC > source a battery. It seems though that when I connect my battery to BOARD it > everything works as desired! So the question becomes, can I draw power from > the stack instead of applying power to it? For instance, can I attach my > battery to the BOARD header and then connect my circuit to the MOTOR header > to supply it power? Seems like I should be able to but I plan on testing it. Yeah - that should work fine. BOARD and V_MOTOR are connected in parallel by default. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ gumstix-users mailing list gum...@li... https://lists.sourceforge.net/lists/listinfo/gumstix-users |
From: Dave H. <dhy...@gm...> - 2009-08-16 17:15:05
|
Hi Dustin, >> Sparkfun just came out with a nice little DC-DC converter module: >> <http://www.sparkfun.com/commerce/product_info.php?products_id=9275> >> These are much more efficient than linear regulators, and you'll also >> get more battery life. > > It just so happens that I picked up the components for my power supply > circuit from sparkfun > <http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=57>, > <http://www.sparkfun.com/commerce/product_info.php?products_id=8373> and > learned how to build it from their tutorial > <http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=57>. > Reviewing the components of the circuit it seems it should be able to supply > enough current. Yep - everything seems good. You need to make sure that you get the right caps on the 7805 or it won't work properly. The 7805 is a linear regulator. >> Yeah - that should work fine. BOARD and V_MOTOR are connected in >> parallel by default. > > When I burnt the trace on my Robostix lastnight I was trying to determine > whether the power coming from V_MOTOR was regulated. I suspect not but I > wanted to be certain. Do you happen to know? Also is it safe to connect the > battery (5 Cell 6V NiMH) directly to the Robostix or must I regulate it > first? V_MOTOR and BOARD are inputs to the regulators on the robostix, so do not need to be regulated. You can see this by looking at the robostix schematics: <http://pubs.gumstix.com/boards/ROBOSTIX/PCB00019-R1131/> Actually V_MOTOR is wired up to the +ve voltage on the PWM pins, and by default there is a jumper which connects V_MOTOR and V_ROBOBATT (what's on the BOARD connector) together. The fact that you burned up a trace on the board means that somehow that trace got into part of the circuit that was drawing alot of current. Which means that something was definitely not wired correctly. If you take a 6 volt battery and connected the positive end to one side of the trace and the negative end to the other side of the trace, it would definitely do that. NiMH batteries are capable of delivering enough current to melt metal (I've done that myself by accident - using a 6V NiMH pack from an old laptop - D sized cells). -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: Dustin W. <dus...@ya...> - 2009-08-16 20:55:18
|
Hello again: > Yep - everything seems good. You need to make sure that you get the > right caps on the 7805 or it won't work properly. > The 7805 is a linear regulator. Please forgive me if this is a silly question, I am really new to this stuff, but what constitutes the right caps? I'm using the ones specified in the sparkfun tutorial. Are they acceptable for this application? Is there a better choice? > V_MOTOR and BOARD are inputs to the regulators on the robostix, so do > not need to be regulated. You can see this by looking at the robostix > schematics: > <http://pubs.gumstix.com/boards/ROBOSTIX/PCB00019-R1131/> That's what I thought based on the information in the wiki but it's comforting to get confirmation. > Actually V_MOTOR is wired up to the +ve voltage on the PWM pins, and > by default there is a jumper which connects V_MOTOR and V_ROBOBATT > (what's on the BOARD connector) together. This jumper is still in place which implies to me that even though these connectors lead to voltage regulators pulling the voltage that comes off the board will be exactly that which I put into the board because it has not passed through the regulators at that point. Is my assumption correct? > The fact that you burned up a trace on the board means that somehow > that trace got into part of the circuit that was drawing alot of > current.Which means that something was definitely not wired > correctly. I understand, I just don't know if connecting my multimeter to V_MOTOR while applying power to the BOARD header could have caused this issue. I didn't have the problem the first time I applied power to the BOARD header but it seems plausible that I didn't apply power long enough for the issue to arise. I fear that attaching my battery to the BOARD header and then trying to pull power off V_MOTOR will have the same effect. I suppose I could run power from the battery to Verdex/Robostix stack and my circuit separately but then how does this impact serial communication between those two? TIA, Dustin Webb |
From: Dave H. <dhy...@gm...> - 2009-08-17 03:19:52
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Hi Dustin, On Sun, Aug 16, 2009 at 1:55 PM, Dustin Webb<dus...@ya...> wrote: > Hello again: > >> Yep - everything seems good. You need to make sure that you get the >> right caps on the 7805 or it won't work properly. >> The 7805 is a linear regulator. > > Please forgive me if this is a silly question, I am really new to this > stuff, but what constitutes the right caps? I'm using the ones specified in > the sparkfun tutorial. Are they acceptable for this application? Is there a > better choice? I expect that they're fine. The "right" ones can only be determined by looking at the datasheet for the particular regulator you're using. >> V_MOTOR and BOARD are inputs to the regulators on the robostix, so do >> not need to be regulated. You can see this by looking at the robostix >> schematics: >> <http://pubs.gumstix.com/boards/ROBOSTIX/PCB00019-R1131/> > > That's what I thought based on the information in the wiki but it's > comforting to get confirmation. > >> Actually V_MOTOR is wired up to the +ve voltage on the PWM pins, and >> by default there is a jumper which connects V_MOTOR and V_ROBOBATT >> (what's on the BOARD connector) together. > > This jumper is still in place which implies to me that even though these > connectors lead to voltage regulators pulling the voltage that comes off the > board will be exactly that which I put into the board because it has not > passed through the regulators at that point. Is my assumption correct? Yep. >> The fact that you burned up a trace on the board means that somehow >> that trace got into part of the circuit that was drawing alot of >> current. Which means that something was definitely not wired >> correctly. > > I understand, I just don't know if connecting my multimeter to V_MOTOR while > applying power to the BOARD header could have caused this issue. I didn't > have the problem the first time I applied power to the BOARD header but it > seems plausible that I didn't apply power long enough for the issue to > arise. I fear that attaching my battery to the BOARD header and then trying > to pull power off V_MOTOR will have the same effect. I suppose I could run > power from the battery to Verdex/Robostix stack and my circuit separately > but then how does this impact serial communication between those two? The only way a multimeter probe should have any impact is if it accidentally shorts out a couple of connections. Personally, I don't see how using a multimeter could cause the trace to burn up. I can only imagine that that could happen due to something being wired up incorrectly. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |