Stephen, If you can restrict your hopping to a 20 MHz range, then you can use a sample rate of 20 Msps and hop instantly (well, within a 50 ns sample period) in software.
If you need to hop over more than 20 MHz and must control the hopping from a host computer over USB, then your tuning time will be dominated by USB latency. I'm not sure how quickly you would be able to tune, but I guess something like 2 ms. If you can tune in firmware, then you can reduce the tuning time considerably. I've measured tuning times between 145 us and 750 us from firmware. I haven't done much work to optimize this, but it is probably possible to achieve consistent sub-200 us tuning time for most applications. Tuning doesn't take much CPU time. The reasons it takes time (roughly in order) are: 1. USB latency (if controlled by host computer) 2. inter-chip serial communication 3. PLL settling You might find this talk interesting: https://www.youtube.com/watch?v=3AZgQzrevjo Mike On Wed, Jul 06, 2016 at 03:48:39AM +0000, Yen, Stephen wrote: > > Hello, > > I have a HackRF One that's been running various transmitter modulation > schemes and would like to know how quickly one could hop around in carrier > frequency. For example, how much time is required to sweep a 1MHz BW data > message on an FM modulated carrier starting from 600MHz to 700MHz in 1MHz > intervals (around 100 channels)? Is the time needed to switch carrier > frequencies mainly dependent on the internal CPU execution time? > > Thanks, > -Stephen _______________________________________________ HackRF-dev mailing list [email protected] https://pairlist9.pair.net/mailman/listinfo/hackrf-dev
