Thanks Sungiin, Do you know a route to capture ADC and store in memory (eg SSD on USB, etc.) RT ? Is this possible? jb
On Wednesday, April 16, 2014 6:23:28 PM UTC-4, Sungjin Chun wrote: > > From http://processors.wiki.ti.com/index.php/AM335x_ADC_Driver%27s_Guide, > ADC in AM335x can sample in 200KSPS(Kilo Samples Per Second) so 44K could > be possible. However I think you have to do this with faster interface > which means > you cannot use sysfs; instead you have to use /dev/mem or PRU. > > I have very simple example of using ADC in these manner. > > 1. Using /dev/mem > > https://github.com/chunsj/nxctrl/blob/master/adc-test.c > > 2. Using PRU > > https://github.com/chunsj/nxctrl/blob/master/adcpru-test.p > > Though I'm not sure on your exact needs, I hope this can help you. > > > > > On Wed, Apr 16, 2014 at 10:52 PM, <[email protected] > <javascript:>>wrote: > >> Hi all people here. >> >> I must to say im newbie in BB and RT data. >> >> So, im going to ask simple: >> I need to acquire in ADC of the BB in RT over 44khz, only read, i dont >> need to process it in RT >> is it possible to use the ADC of the BB to do it and DMA..? >> >> If it possible, can you show me some sample code to start with, or where >> to look at? (some link).. >> >> Really thanks >> >> El lunes, 10 de septiembre de 2012 07:29:55 UTC-4:30, Evan Thomas >> escribió: >>> >>> >>> Hello, >>> >>> embedded/real time/hardware newbie here. I have an requirement to read >>> an ADC, perform some simple FP calculations and write to DAC. It needs to >>> be at least 20KHz but importantly the latency on the DAC/ADC needs to less >>> than 10us. Low jitter is also important. Is the beaglebone up to it? I see >>> this asked many times but not answered so I am not really expecting an >>> answer now :) >>> >>> I have two specific questions >>> >>> 1) This might be naive but I thought I would try the PREEMPT_RT patch. >>> In particular, I wanted to combine it with Robert Nelson's patches and >>> build process. After many hours of random git commands, patch and modifying >>> scripts I came to the conclusion that the current PREEMPT_RT patch is for >>> 3.4 whereas Robert's patches are for 3.6. Firstly, does it even make sense >>> to try PREEMPT_RT on BB? If so, what is the best way to proceed? Use 3.4 >>> versions of Robert's patches and risk bugs and missing features? Wait >>> for PREEMPT_RT patch against 3.6? >>> >>> 2) What is the best way to do low latency (<10us) 14bit ADC and DAC on >>> the BB? I assume it would have to be over the SPI bus, but beyond that I'm >>> clueless. If someone can point me in the right direction I would really >>> appreciate it. >>> >>> Thanks, >>> Evan. >>> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> 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 the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
