This particular problem sounds reasonable straightforward with a few fpga edits. I have successfully commandeered a few gpios in the E310 before for scoping a couple clock signals.
One possible suggestion for a quick fix: when you set a master clock rate, then the radio_clk wire in the fpga will run at that frequency. So at 1 MHz, radio_clk would be high for 0.5 us, low for 0.5 us. This is by definition synchronized with the digital sampling. I'd buffer it with a higher rate signal (bus_clk, for example, which runs at 50 MHz), then you could pretty easily route it out one of the gpios. Hope that helps, EJ On Jul 14, 2017 4:58 PM, "Marcus D. Leech via USRP-users" < usrp-users@lists.ettus.com> wrote: On 07/11/2017 11:56 AM, Will Thompson via USRP-users wrote: Hi all. So I’m thinking of starting a project with the E310 that requires high accuracy control of a switch. Basically I need to receive a single RF sample (@1MHz) (1us), then send a signal via the GPIO on a second sample (2us), and then receive a signal again on the third sample (3us) and alternate between these functions for a period of time. I was wondering if anyone has experience with controlling the GPIOs on the E310, and knows how accurate you can synchronise the signal outputs with RF received samples? i.e. Can I synchronise the GPIO signalling and the received RF sampling down to micro seconds? Also, if anyone has any good resource links for the E310 and GPIO could you pass them on please? Kind regards Will The GPIO interface is normally accessed using UHD host-side API elements, which operate asynchronously to the sample stream, so there's no way to guarantee really-tight timing. You'd likely need to dive into FPGA coding to achieve this type of application. https://files.ettus.com/manual/page_gpio_api.html Has a little bit of information, but deep answers to your query can be found in the FPGA source code. -- William Thompson Ph.D. Senior Research Engineer Toshiba Research Europe Limited 32 Queen Square, Bristol, BS1 4ND, UK Tel: +44 (0) 117 906 0734 ------------------------------ NOTE: The information in this email and any attachments may be confidential and/or legally privileged. This message may be read, copied and used only by the intended recipient. If you are not the intended recipient, please destroy this message, delete any copies held on your system and notify the sender immediately. Toshiba Research Europe Limited, registered in England and Wales (2519556). Registered Office 208 Cambridge Science Park, Milton Road, Cambridge CB4 0GZ, England. Web: www.toshiba.eu/research/trl ------------------------------ This email has been scanned for email related threats and delivered safely by Mimecast. For more information please visit http://www.mimecast.com ------------------------------ _______________________________________________ USRP-users mailing listUSRP-users@lists.ettus.comhttp://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com _______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
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