From: Gerardo R. <ge...@di...> - 2011-06-20 20:27:43
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hi! what do you think could be a good option to interconnect several gumstix boards? I've seen the StageCoach, and it's definitely an answer, but I'm wondering if there is a simbler solution with probably not as high throughput, but still decent. For example, if only two devices to connect, two mirrored SPI connections could work very well (both devices as master and slave) and give up to... how much? 48 Mbps? Do you think USB could be an option too? I'm thinking on using a custom board where the gumstix (more than 2) will be mounted, so I would love to avoid a USB hub, how possible do you see this option? Any other high speed options? thanks a lot for any help! gera |
From: Marshall C. <ma...@gm...> - 2011-06-20 23:04:11
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Is Ethernet out of the question? That's going to give you the highest throughput by far. If that's not an option, you could always do a Wifi adhoc network unless low power is a concern. And of course there is always the option of connecting serial ports. You could buy a ttl to RS-485 adapter and connect multiple boards to a single serial "network". I would stay away from SPI, I2C, and USB simply because of the unneeded complexity. Good Luck, Marshall 2011/6/20 Gerardo Richarte <ge...@di...>: > hi! > what do you think could be a good option to interconnect several > gumstix boards? > I've seen the StageCoach, and it's definitely an answer, but I'm > wondering if there is a simbler solution with probably not as high > throughput, but still decent. For example, if only two devices to > connect, two mirrored SPI connections could work very well (both devices > as master and slave) and give up to... how much? 48 Mbps? > > Do you think USB could be an option too? I'm thinking on using a > custom board where the gumstix (more than 2) will be mounted, so I would > love to avoid a USB hub, how possible do you see this option? > > Any other high speed options? > > thanks a lot for any help! > gera > > > ------------------------------------------------------------------------------ > EditLive Enterprise is the world's most technically advanced content > authoring tool. Experience the power of Track Changes, Inline Image > Editing and ensure content is compliant with Accessibility Checking. > http://p.sf.net/sfu/ephox-dev2dev > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > |
From: Gerardo R. <ge...@di...> - 2011-06-21 06:20:00
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Marshall, thanks a lot for the ideas! On 06/20/11 20:04, Marshall Crocker wrote: > Is Ethernet out of the question? well... may be, not completely though. All the Gumstix will be on the same board, and we need to minimize the chip count for a very good reason. The StageCoach design has one extra chip for every gumstix (MMIO to ethernet) and one extra chip for the whole thing (an ethernet switch). Our current idea is to use a single FPGA to interconnect all the Gumstix, and I thought using SPI to connect to the FPGA... MMIO could also be an option of course, and will give us higher throughput, but I think it'll make the FPGA design more complex, but I could be wrong... another issue with MMIO is that it'll consume lots of pins (data and address) which I could need for something else (like SPI, I2C, etc). But I'm not sure about this, I'd have to sit down to check pin by pin. > If that's not an option, you could always do a > Wifi adhoc network unless low power is a concern. Power is in fact a concern, and we will be very likely not using the WiFi enabled sticks. > And of course there is always the option of connecting serial ports. This would be kind of lower speed than SPI, even if I push it up to 3.6 mbps... and then, you think I could mange to somehow implement any-to-any communications? oh well... it's not like I want to use an FPGA, but as I said, chip count is really an issue :( thanks again! gera |
From: Marshall C. <ma...@gm...> - 2011-06-21 13:38:33
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An FPGA will make using SPI much easier. We have our gumstix custom board connected to an FPGA and use SPI 3 for data transfer. We are connecting to sensors, not other gumstix modules though. That will probably be your best overall option for low power, high speed, low chip count. Of course it will take a bit of work for the FPGA implementation and linux slave code. Marshall 2011/6/21 Gerardo Richarte <ge...@di...>: > Marshall, thanks a lot for the ideas! > > On 06/20/11 20:04, Marshall Crocker wrote: >> Is Ethernet out of the question? > well... may be, not completely though. All the Gumstix > will be on the same board, and we need to minimize the > chip count for a very good reason. The StageCoach design > has one extra chip for every gumstix (MMIO to ethernet) > and one extra chip for the whole thing (an ethernet switch). > > Our current idea is to use a single FPGA to interconnect > all the Gumstix, and I thought using SPI to connect to the > FPGA... MMIO could also be an option of course, and will > give us higher throughput, but I think it'll make the FPGA > design more complex, but I could be wrong... another > issue with MMIO is that it'll consume lots of pins (data and > address) which I could need for something else (like SPI, > I2C, etc). But I'm not sure about this, I'd have to sit down > to check pin by pin. >> If that's not an option, you could always do a >> Wifi adhoc network unless low power is a concern. > Power is in fact a concern, and we will be very likely not > using the WiFi enabled sticks. >> And of course there is always the option of connecting serial ports. > This would be kind of lower speed than SPI, even if I push it > up to 3.6 mbps... and then, you think I could mange to > somehow implement any-to-any communications? > > oh well... it's not like I want to use an FPGA, but as I said, > chip count is really an issue :( > > thanks again! > gera > > ------------------------------------------------------------------------------ > EditLive Enterprise is the world's most technically advanced content > authoring tool. Experience the power of Track Changes, Inline Image > Editing and ensure content is compliant with Accessibility Checking. > http://p.sf.net/sfu/ephox-dev2dev > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > |
From: Neil M. <ne...@gu...> - 2011-07-04 22:32:14
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The RoboVero expansion board has a CAN transceiver that can be used to network Overo COMs easily. The schematic is here. http://pubs.gumstix.com/boards/ROBOVERO/PCB30019.pdf - Neil On 11-06-21 06:38 AM, Marshall Crocker wrote: > An FPGA will make using SPI much easier. We have our gumstix custom > board connected to an FPGA and use SPI 3 for data transfer. We are > connecting to sensors, not other gumstix modules though. That will > probably be your best overall option for low power, high speed, low > chip count. Of course it will take a bit of work for the FPGA > implementation and linux slave code. > > Marshall > > 2011/6/21 Gerardo Richarte<ge...@di...>: >> Marshall, thanks a lot for the ideas! >> >> On 06/20/11 20:04, Marshall Crocker wrote: >>> Is Ethernet out of the question? >> well... may be, not completely though. All the Gumstix >> will be on the same board, and we need to minimize the >> chip count for a very good reason. The StageCoach design >> has one extra chip for every gumstix (MMIO to ethernet) >> and one extra chip for the whole thing (an ethernet switch). >> >> Our current idea is to use a single FPGA to interconnect >> all the Gumstix, and I thought using SPI to connect to the >> FPGA... MMIO could also be an option of course, and will >> give us higher throughput, but I think it'll make the FPGA >> design more complex, but I could be wrong... another >> issue with MMIO is that it'll consume lots of pins (data and >> address) which I could need for something else (like SPI, >> I2C, etc). But I'm not sure about this, I'd have to sit down >> to check pin by pin. >>> If that's not an option, you could always do a >>> Wifi adhoc network unless low power is a concern. >> Power is in fact a concern, and we will be very likely not >> using the WiFi enabled sticks. >>> And of course there is always the option of connecting serial ports. >> This would be kind of lower speed than SPI, even if I push it >> up to 3.6 mbps... and then, you think I could mange to >> somehow implement any-to-any communications? >> >> oh well... it's not like I want to use an FPGA, but as I said, >> chip count is really an issue :( >> >> thanks again! >> gera >> >> ------------------------------------------------------------------------------ >> EditLive Enterprise is the world's most technically advanced content >> authoring tool. Experience the power of Track Changes, Inline Image >> Editing and ensure content is compliant with Accessibility Checking. >> http://p.sf.net/sfu/ephox-dev2dev >> _______________________________________________ >> gumstix-users mailing list >> gum...@li... >> https://lists.sourceforge.net/lists/listinfo/gumstix-users >> > > ------------------------------------------------------------------------------ > EditLive Enterprise is the world's most technically advanced content > authoring tool. Experience the power of Track Changes, Inline Image > Editing and ensure content is compliant with Accessibility Checking. > http://p.sf.net/sfu/ephox-dev2dev > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users |