BBB - Read high speed ADC via GPIO pins

hamidreza

Other Parts Discussed in Thread: ADS4149

Hi,

I am using Beaglebone black (BBB) and for some specific reasons I need to connect it to an external high speed ADC (more than 30 MHZ and maximum about 100 MHz) .

I am thinking to connect the parallel output data of the ADC board to the GPIO pins of BBB and read-store the data. I see in the catalogue that it is possible to directly access to the GPIO pins by the processor (AM335x).

I wonder if it is possible to read the ADC data and save them somewhere in memory in such a way that I don't loss the high speed data (about and more than 30 MHz)?

I don't know how many instruction does it take that the processor access to GPIO data?

(Please note that due to the physical sizing requirement in my application, I cannot use any FPGA boards for this purpose and I must only use a very small board such as BBB.)

Thanks a lot in advance!

Looking forward to hearing from you.

Cheers,

Hamid

over 11 years ago

0 Biser Gatchev-XID over 11 years ago

TI__Guru**** 393215 points

Hi Hamid,

There is no way that you can achieve frequencies like these via GPIO. What is the ADC part number? Have you checked whether it can be attached to the GPMC interface?

0 hamidreza over 11 years ago in reply to Biser Gatchev-XID

Prodigy 160 points

Hi,

Thanks for the quick reply,

the ADC board that I am going to use is "ADS4149 EVM" from TI. The GPMC has a speed limitation, what I need is the speed rate more than 30 MHZ...so there is no sulotion for that?

0 Biser Gatchev-XID over 11 years ago in reply to hamidreza

TI__Guru**** 393215 points

From what I saw of this EVM, first of all it uses LVDS data output. The AM335X has no way to connect to this. If CMOS output mode is used, it would only be possible to capture data into the AM335X PRU-ICSS, but then there is no software available for this, you will have to write your own. For both cases the BB Black is not usable.

0 hamidreza over 11 years ago in reply to Biser Gatchev-XID

Prodigy 160 points

Hi Biser,

Thanks again. About the ADC output, I got your point. But about capturing the data into RPU, does the software can access to GPIO fast enough?

You mentioned that BBB is usable even if RPU is used?

By the way do you have any alternative to do the high speed capturing from TI product? (an stand-alone board with a small size possibly including embedded memory )

It will help me a lot...

Thanks again and regards,

hamid

0 Biser Gatchev-XID over 11 years ago in reply to hamidreza

TI__Guru**** 393215 points

Hi Hamid,

From what I see here: http://www.ti.com/tool/ads41b49evm#Technical Documents it seems that this ADC is mainly intended to be interfaced to FPGAs. There is a capture board mentioned in the EVM user guide: https://estore.ti.com/TSW1200EVM-TSW1200-High-Speed-ADC-LVDS-Evaluation-System-P1045.aspx. If you have more questions about this ADC please direct them to this dedicated forum: http://e2e.ti.com/support/data_converters/high_speed_data_converters/default.aspx

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BBB - Read high speed ADC via GPIO pins