It will be impossible to do that with that amount of channels. Each sample has 16 bit.
48 Channels * 450 kS/s * 16 bit = 345.6 Mbit/S. Besides that is probably beyond any bus speed on the SoC. It would as well require you to interface with 24 SPI lines in parallel in full speed. There is absolutely no way to do that on a BeagleBone. You'll have to go for a FPGA or a faster ADC with analog multiplexing in you front-end. Bests, Julian On Tue, Sep 22, 2015 at 6:10 PM, Antônio Albuquerque <[email protected]> wrote: > something around 450kS/s > > > 2015-09-22 12:47 GMT-03:00 Julian David Rath <[email protected]>: >> >> What is your planned sample frequency? >> >> On Tue, Sep 22, 2015 at 4:50 PM, Antônio Albuquerque <[email protected]> >> wrote: >> > Hello Julian >> > >> > Thank you for your fast reply. >> > I am trying to use the same ADS8528 to read 48 channel of sensors using >> > daisy-chain to get the information simultaneously. >> > Definitely I appreciate if you can send me some code. >> > >> > Best regards, >> > Antonio >> > >> > >> > 2015-09-22 10:48 GMT-03:00 Julian David Rath <[email protected]>: >> >> >> >> Hej Antonio, >> >> >> >> I used the PRU to communicate with the BBB, which works quite good. >> >> But datarates with more the 20 Mbit are not realistic since the PRUs >> >> have a clock of 200 Mhz. >> >> If you are interested I could prepare some code to release. >> >> >> >> bests, >> >> >> >> Julian >> >> >> >> >> >> On Tue, Sep 22, 2015 at 2:52 AM, <[email protected]> wrote: >> >> > Hello Julian, >> >> > I am having the same issue, could you let me know about the solution? >> >> > Have >> >> > you found some workaround to use BBB->SPI and ADS8528? >> >> > Best regards >> >> > Antonio >> >> > >> >> > >> >> > Em segunda-feira, 10 de março de 2014 07:15:25 UTC-3, Julian David >> >> > Rath >> >> > escreveu: >> >> >> >> >> >> Hi, >> >> >> >> >> >> I just found out that this is a better place to ask my question, it >> >> >> seams >> >> >> like there is also a beaglebone Google group, little confusing. So >> >> >> here >> >> >> my >> >> >> cross-post: >> >> >> >> >> >> I'd like to connect 4 ADS8528[0] daisy-chained via SPI to a BBB. I >> >> >> want >> >> >> to >> >> >> test it in different iterations first I want to measure the 32 >> >> >> Analog >> >> >> input >> >> >> channels captured by the ADS8528s with 1kHz and at the end with >> >> >> 200kHz. >> >> >> Those ADS8528 using 4 SPI Channels in daisy-chain mode. So I did >> >> >> some >> >> >> calculations on the needed bandwidth: >> >> >> >> >> >> for 1Khz: >> >> >> 12Bit * 32Channels * 4KHz = 384 Kbit/s >> >> >> >> >> >> On 4 SPI Channels that means: >> >> >> 12* 32*1Khz = 96 Kbit/s per SPI channel >> >> >> >> >> >> for 200Khz: >> >> >> 12Bit * 32Channels * 200KHz = 76.8 Mbit/s = 9.6MByte/s >> >> >> >> >> >> On 4 SPI Channels that means: >> >> >> 76.8Mb/s /4 = 19.2 Mbit/s per SPI channel >> >> >> >> >> >> Now 2 things: >> >> >> * Should/Can I use the built-in SPI of the BBB or do I have to >> >> >> implement >> >> >> 4 channels SPI bus by hand (High datarates PRUSS I guess)? >> >> >> * Do you think the high datarates for the 200Khz are achievable? >> >> >> >> >> >> Thanks, >> >> >> >> >> >> /Julian >> >> >> >> >> >> [0]: http://www.ti.com/product/ads8528 >> >> > >> >> > -- >> >> > For more options, visit http://beagleboard.org/discuss >> >> > --- >> >> > You received this message because you are subscribed to a topic in >> >> > the >> >> > Google Groups "BeagleBoard" group. >> >> > To unsubscribe from this topic, visit >> >> > >> >> > https://groups.google.com/d/topic/beagleboard/SpRz6u9_8aA/unsubscribe. >> >> > To unsubscribe from this group and all its topics, send an email to >> >> > [email protected]. >> >> > For more options, visit https://groups.google.com/d/optout. >> >> >> >> -- >> >> For more options, visit http://beagleboard.org/discuss >> >> --- >> >> You received this message because you are subscribed to a topic in the >> >> Google Groups "BeagleBoard" group. >> >> To unsubscribe from this topic, visit >> >> https://groups.google.com/d/topic/beagleboard/SpRz6u9_8aA/unsubscribe. >> >> To unsubscribe from this group and all its topics, send an email to >> >> [email protected]. >> >> For more options, visit https://groups.google.com/d/optout. >> > >> > >> > >> > >> > -- >> > Atenciosamente, >> > Antônio Albuquerque >> > >> > -- >> > For more options, visit http://beagleboard.org/discuss >> > --- >> > You received this message because you are subscribed to a topic in the >> > Google Groups "BeagleBoard" group. >> > To unsubscribe from this topic, visit >> > https://groups.google.com/d/topic/beagleboard/SpRz6u9_8aA/unsubscribe. >> > To unsubscribe from this group and all its topics, send an email to >> > [email protected]. >> > For more options, visit https://groups.google.com/d/optout. >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to a topic in the >> Google Groups "BeagleBoard" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/beagleboard/SpRz6u9_8aA/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> [email protected]. >> For more options, visit https://groups.google.com/d/optout. > > > > > -- > Atenciosamente, > Antônio Albuquerque -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. 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