>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]> 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]. > 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.
