Re: [Discuss-gnuradio] Sync 2x USRP2s

2010-03-19 Thread Josh Blum
You need the sleep(1) to guarantee that the time is latched into the registers before starting streaming. Prior to that, the time is unknown. And there seems to be a little bug in the fpga that makes the streaming hang if this time happens to be in the past. When I update the example, I will

Re: [Discuss-gnuradio] Sync 2x USRP2s

2010-03-19 Thread Lyndon Evans
Hi Doug, Thanks for the quick reply. In rx_timed_samples I basically do start_rx_streaming() right after set_time_at_next_pps(), so yeah, I'll try the sleep(1). What do you mean by "if the host PC doesn't have direct access to the PPS signal" (read the serial data from the GPS)? Yes, I've r

Re: [Discuss-gnuradio] Sync 2x USRP2s

2010-03-19 Thread Doug Geiger
On 3/19/2010 10:48 AM, David Evans wrote: Hi, I want to sync two USRP2s, and currently trying to modify the VRT rx_timed_samples... usrp2::clock_config_t cc; cc.ref_source = usrp2::clock_config_t::REF_INT; cc.pps_polarity = usrp2::clock_config_t::PPS_NEG; cc.pps_source = usrp2::clock_config_t

[Discuss-gnuradio] Sync 2x USRP2s

2010-03-19 Thread David Evans
Hi, I want to sync two USRP2s, and currently trying to modify the VRT rx_timed_samples... usrp2::clock_config_t cc; cc.ref_source = usrp2::clock_config_t::REF_INT; cc.pps_polarity = usrp2::clock_config_t::PPS_NEG; cc.pps_source = usrp2::clock_config_t::PPS_SMA; cc.provide_ref_to_mimo = false;