You don't specify a delay, you send one timed command to make the pin go HIGH, and another timed command to make it go LOW. And the two command-times should be "your delay" apart.
This may help: https://www.youtube.com/watch?v=ppD06ZETnek&t=75s&pp=ygUPZ3Jjb24gdXNycCBncGlv --M On Sat, Feb 22, 2025 at 12:12 PM <kavin...@atindriya.co.in> wrote: > Hi, > How to give the delay in uhd_usrp_set_command_time(uhd_usrp_handle > h,int64_t full_secs,double frac_secs,size_t mboard) function? > > > > > > > > > > On 2025-02-22 00:10, Marcus D. Leech wrote: > > On 21/02/2025 23:56, kavin...@atindriya.co.in wrote: > >> Hi, > >> Can I use usleep(1) or any other technique is there for GPIO . > >> > > You might be able to use timed commands: > > > > https://files.ettus.com/manual/page_timedcmds.html#timedcmds_gen_cmds > > > > But since usleep() cannot guarantee any kind of maximum period that > > your process will go to sleep, it is an unreliable > > method when precision and repeatable timing of ANY kind of "doing > > stuff with external hardware" is required. Even if > > usleep() at microsecond-scale intervals *WAS* reliable and > > repeatable, there's no guarantee about all the *other* things > > that are required to launch a command over a latency-not-guaranteed > > bus to the external hardware, including kernel-layer > > USB drivers, etc, etc. > > > > > >> > >> On 2025-02-21 23:37, Marcus D. Leech wrote: > >>> On 21/02/2025 23:22, kavin...@atindriya.co.in wrote: > >>>> Hi, > >>>> Thanks for answering. > >>>> Can you explain me clearly? > >>>> > >>>> Thanks. > >>> I'd suggest, at a minimum, looking at the MAN page for usleep(). > >>> > >>> > >>>> > >>>> > >>>> > >>>> On 2025-02-21 23:11, Marcus D. Leech wrote: > >>>>> On 21/02/2025 23:05, kavin...@atindriya.co.in wrote: > >>>>>> Hi, > >>>>>> In USRP B205mini-i I am able to access the GPIO Pin. I have to > >>>>>> create a Pulse in the GPIO pin. I want to make high the gpio pin > >>>>>> for 1microsecond and low for 999microseconds. How to achieve this > >>>>>> timings through coding. Can you give me the solution for this? > >>>>>> > >>>>>> In coding after making high I am giving usleep(1) function but > >>>>>> when I am check in the oscilloscope it is showing 64microseconds. > >>>>>> How? > >>>>>> > >>>>>> > >>>>> Because an application-land program executing on an ordinary > >>>>> general-purpose operating system is unlikely to be able to > >>>>> achieve repeatable, 1usec-scale timing. This has nothing to do, > >>>>> per se, with UHD or USRPs, but rather, to understanding > >>>>> how applications execute in a general-purpose operating system > >>>>> that isn't ruthlessly optimized for "hard" real-time tasks. > >>>>> > >>>>> > >>>>> _______________________________________________ > >>>>> USRP-users mailing list -- usrp-users@lists.ettus.com > >>>>> To unsubscribe send an email to usrp-users-le...@lists.ettus.com > >>> _______________________________________________ > >>> USRP-users mailing list -- usrp-users@lists.ettus.com > >>> To unsubscribe send an email to usrp-users-le...@lists.ettus.com > > _______________________________________________ > > USRP-users mailing list -- usrp-users@lists.ettus.com > > To unsubscribe send an email to usrp-users-le...@lists.ettus.com > _______________________________________________ > USRP-users mailing list -- usrp-users@lists.ettus.com > To unsubscribe send an email to usrp-users-le...@lists.ettus.com >
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