http://lmgtfy.com/?q=AM335c+ADC+module -> http://processors.wiki.ti.com/index.php/AM335x_ADC_Driver's_Guide#Introduction
An analog-to-digital converter (abbreviated ADC) is a device that uses > sampling to convert a continuous quantity to a discrete time representation > in digital form. > > The TSC_ADC_SS (Touchscreen_ADC_subsystem) is an 8 channel general purpose > ADC, with optional support for interleaving Touch Screen conversions. The > TSC_ADC_SS can be used and configured in one of the following application > options: > > - 8 general purpose ADC channels > - 4 wire TS, with 4 general purpose ADC channels > - 5 wire TS, with 3 general purpose ADC channels > - 8 wire TS > > *ADC used is 12 bit SAR ADC with a sample rate of 200 KSPS (Kilo Samples > Per Second).* The ADC samples the analog signal when "start of > conversion" signal is high and continues sampling 1 clock cycle after the > falling edge. It captures the signal at the end of sampling period and > starts conversion. It uses 12 clock cycles to digitize the sampled input; > then an "end of conversion" signal is enabled high indicating that the > digital data ADCOUT<11:0> is ready for SW to consume. A new conversion > cycle can be initiated after the previous data is read. Please note that > the ADC output is positive binary weighted data. > On Mon, Jun 20, 2016 at 2:33 PM, <[email protected]> wrote: > > the best woud be the PRU because you can store the data in the share > memory. > > Do you mean the 12KB data memory? As I understand it, it's only shared > between PRUs, not directly with the CPU. Moving data from there to the CPU > would require DMA, as 'programmed' access would not keep up with 1.6 MSPS. > Is that right? But if I understand correctly, the ADC can be configured to > send its results (through an intermediate FIFO) to DMA, so the PRU would > just be a needless layer of complexity. > > Of course, If I could find free or inexpensive software that needed little > or no modification to do the job, I wouldn't mind if it happened to use the > PRU :) > > Thanks. > > On Monday, June 20, 2016 at 12:53:28 PM UTC-7, Micka wrote: >> >> the best woud be the PRU because you can store the data in the share >> memory. That is the fastest way. >> >> you can stop the acquisition whenever you want or let it go back at the >> beginning of your memory and go on. >> >> >> Le lun. 20 juin 2016 à 21:29, <[email protected]> a écrit : >> >>> I'm looking to write a simple app for BBB. When started from the >>> command line, it would set up the ADC in continuous mode and read ~1 M >>> samples from e.g. AN0 into memory. After the capture is complete, it would >>> write the data to a file and exit. >>> >>> Ideally, it would run at the hardware limit of 1.6 MSPS (15 cycles of 24 >>> MHz adc_clk per sample). If that's not practical, 800 KSPS or better would >>> be acceptable. >>> >>> What is an easy way to do this? Most Beaglebone ADC examples sample at >>> kilohertz rates or slower. >>> >>> This guide: >>> http://processors.wiki.ti.com/index.php/Linux_Core_ADC_User%27s_Guide >>> speaks of 200 KSPS. What is the limitation here? >>> >>> I've seen various suggestions to use the PRU, but don't understand why. >>> I would think that since DMA would be required anyway, there should be no >>> requirement to otherwise access the hardware with tight timing. If PRU is >>> indeed necessary, is there a suitable example or tutorial? (None of the >>> libpruio built-in examples deal with rapid sampling or large amounts of >>> data.) >>> >>> Any other ideas for a simple way to capture data fast will be gratefully >>> appreciated. >>> >>> Thanks. >>> >>> -- >>> 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]. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/beagleboard/c5cae6bf-c8e0-45c4-ab5b-6bc236766d09%40googlegroups.com >>> <https://groups.google.com/d/msgid/beagleboard/c5cae6bf-c8e0-45c4-ab5b-6bc236766d09%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> 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]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/bd593480-ae6b-453b-addd-0b9cb07036d6%40googlegroups.com > <https://groups.google.com/d/msgid/beagleboard/bd593480-ae6b-453b-addd-0b9cb07036d6%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > 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]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CALHSORr8_iM7HfKT%3DxsbdBgdda_9V5AM%2BD7MMyNUOJWRBv5O3Q%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
