Hi Marcus, Thanks for the detailed answer. I already know get_rx_dboard_iface method as it is it that I use to access the IO of LFRX and LFTX.
The problem is that this is asynchrous. For my need, I would like to feed it synchronously at a defined sample rate for audio purpose for example. Do you think if I write an OOT sink or source that use that method I can get create something near synchronous ? Best regards, Fabien, F4CTZ ---- Marcus Müller a écrit ---- >Just realized that there *is* a C++ API: > >usrp_block->get_device()->get_rx_dboard_iface()->read_aux_adc(); > >replace _rx_ with _tx_ for the LFTX, and read_aux_adc with write_aux_dac for >the DAC. > >Best regards, >Marcus > >DISCLAIMER: Any attached Code is provided As Is. It has not been tested or >validated as a product, for use in a deployed application or system, or for >use in hazardous environments. You assume all risks for use of the Code. Use >of the Code is subject to terms of the licenses to the UHD or RFNoC code with >which the Code is used. Standard licenses to UHD and RFNoC can be found at >https://www.ettus.com/sdr-software/licenses/. > >NI will only perform services based on its understanding and condition that >the goods or services (i) are not for the use in the production or development >of any item produced, purchased, or ordered by any entity with a footnote 1 >designation in the license requirement column of Supplement No. 4 to Part 744, >U.S. Export Administration Regulations and (ii) such a company is not a party >to the transaction. If our understanding is incorrect, please notify us >immediately because a specific authorization may be required from the U.S. >Commerce Department before the transaction may proceed further. > >On 05.03.22 13:31, Marcus Müller wrote: >> Hi Fabien, >> >> no need to modify the FPGA. The functionality is there – it's just not >> exposed to the >> user. Also, note that interacting with the auxiliary ADC and DAC is going to >> be >> asynchronous to the sample flow – there might be millions of samples from >> the main ADC >> that have flown by before an AUX_DAC setting takes effect! >> >> You also don't really need to modify UHD – you *can* use the UHD property >> tree (through >> uspr_block->get_device()->get_tree()->access() ), it's just not a proper, >> stable, >> well-tested, failure-checking API. >> >> Best regards, >> Marcus >> >> On 04.03.22 15:01, Fabien PELLET wrote: >>> Yes, sorry indeed I was talking about AUX_DAC and AUX_ADC that are >>> replicated from the >>> motherboard. >>> >>> I already use IO which works very well. So there is no way to send samples >>> (or receive) >>> at a specific sample rate using that AUX_DAC or ADC. It is just some >>> "analog IOs" for >>> reading some external sensors for example if I understand well what you >>> wrote. >>> >>> What are the specifications of that AUX ? >>> >>> Using a specifique FPGA firmware and custom UHD library, would it be >>> possible to >>> transform them as GR source or sink ? >>> >>> Thanks, >>> >>> Best regards, >>> >>> Fabien, F4CTZ. >>> >>> Le 04/03/2022 à 14:35, Marcus Müller a écrit : >>>> Sorry, hit "send" accidentally: >>>> >>>> Dear Fabien, >>>> >>>> there's no ADC on these daughterboards. Just an EEPROM for identification, >>>> opamps for >>>> amplification and signal conditioning, and on the LFTX a switch-mode power >>>> supply. >>>> You're right, they do exppose the AUX DACs and ADC lines from the >>>> motherboad. >>>> >>>> However, these are without further ado not accessible from UHD, and thus >>>> also not from >>>> GNU Radio. Some daughterboard drivers use them. >>>> >>>> I'm not sure UHD exposes them in all version, but `uhd_usrp_probe --tree` >>>> might show >>>> properties called "AUX_DAC_A" (or _B, or AUX_ADC_.., you get the idea). >>>> You can use >>>> get_device() on your USRP blocks and access theses properties from your >>>> GNU Radio >>>> program (from C++), but it's not really an API – more an exposing of >>>> intestines... >>>> >>>> Best regards, >>>> Marcus >>>> >>>> On 04.03.22 14:30, Marcus Müller wrote: >>>>> Dear Fabien, >>>>> >>>>> there's no ADC on these daughterboards. Just an EEPROM for >>>>> identification, opamps for >>>>> amplification and signal conditioning, and on the LFTX a switch-mode >>>>> power supply. >>>>> >>>>> Best regards, >>>>> Marcus >>>>> >>>>> On 04.03.22 10:30, Fabien PELLET wrote: >>>>>> Hello, >>>>>> >>>>>> As there are IOs available on LFTX and LFRX, there are also ADC and DAC >>>>>> available. >>>>>> >>>>>> Is there a way to use them as SOURCE and SINK in gnuradio for low speed >>>>>> conversion ? >>>>>> >>>>>> Thanks, >>>>>> >>>>>> Best regards, >>>>>> >>>>>> Fabien, F4CTZ. >>>>>> >>>>>> >>>> >>> >
