Jetson/FAQ/BSP/PTP Synchronization
Below steps show how to do PTP synchronization between two Jetson devices.
Steps
1. Prepare two Jetson devices, 1 master DUT 1 slave DUT
2. Install ptp package on both DUTs
sudo apt update sudo apt install linuxptp
3. Run below commands to disable default ptp service on both DUTs
systemctl stop ptp4l systemctl disable ptp4l systemctl reboot
4. Assign static IP to both DUTs
5. Connect two DUTs directly with cable. Make sure two DUTs can ping each other
6. Disable time/date sync using below command on both DUTs
sudo timedatectl set-ntp 0
7. Run below command on slave DUT to set a different timestamp
sudo date 040403312012
8. Run below command on both DUTs
sudo ifconfig eth0 allmulti promisc
9. Run below command on master DUT with gPTP.cfg
sudo ptp4l -i eth0 -m -f gPTP.cfg
10. Run below commands on slave DUT gPTP.cfg (run in different terminal)
sudo ptp4l -i eth0 -m -s -f gPTP.cfg # start ptp daemon sudo phc2sys -w -s eth0 -O 0 # sync system time with ptp
Then you can see slave's system time is synced with master
gPTP.cfg:
[global] # # Default Data Set # twoStepFlag 1 gmCapable 1 priority1 248 priority2 248 domainNumber 0 clockClass 248 clockAccuracy 0xFE offsetScaledLogVariance 0xFFFF free_running 0 freq_est_interval 1 # # Port Data Set # logAnnounceInterval 1 logSyncInterval -3 logMinPdelayReqInterval 0 announceReceiptTimeout 3 syncReceiptTimeout 3 delayAsymmetry 0 fault_reset_interval 4 neighborPropDelayThresh 800 min_neighbor_prop_delay -20000000 # # Run time options # assume_two_step 1 logging_level 6 path_trace_enabled 1 follow_up_info 1 hybrid_e2e 0 tx_timestamp_timeout 1 use_syslog 1 verbose 0 summary_interval 0 kernel_leap 1 check_fup_sync 0 # # Servo options # pi_proportional_const 0.0 pi_integral_const 0.0 pi_proportional_scale 0.0 pi_proportional_exponent -0.3 pi_proportional_norm_max 0.7 pi_integral_scale 0.0 pi_integral_exponent 0.4 pi_integral_norm_max 0.3 step_threshold 0.0 first_step_threshold 0.00002 max_frequency 900000000 clock_servo pi sanity_freq_limit 200000000 ntpshm_segment 0 # # Transport options # [eth0] transportSpecific 0x1 [global] ptp_dst_mac 01:80:C2:00:00:0E p2p_dst_mac 01:80:C2:00:00:0E uds_address /var/run/ptp4l # # Default interface options # network_transport L2 delay_mechanism P2P time_stamping hardware tsproc_mode filter delay_filter moving_median delay_filter_length 10 egressLatency 0 ingressLatency 0 boundary_clock_jbod 0
