Network and Wifi Latency Tool

[Pito Salas]

Hi all,

I was getting some error messages claiming that time stamps from one computer (Raspberry Pi) were not matching up with the other computer (MacOS running VW Ware).So we built a simple tool to check that question. Simple: you run the same program on both computers, with two arguments “A” and “B” on one and “B” and “A” on the other. They start publishing on topics where the payload is their local time and when they receive it on the other end they check. Here is the output. As you can see the two clocks are pretty well synchronized.

I don’t claim this is any brainstorm or invention just a handy tool: https://github.com/Boston-Robot-Hackers/handy

[vmubuntu:~/ros2_ws] ros2 run handy net_latency B A
[INFO] [1761071680.188711005] [B_delay_node]: Node started: subscribing to B_topic, publishing to A_topic
Time skew from A to B is 4.92 ms
Time skew from A to B is 6.14 ms
Time skew from A to B is 7.35 ms
Time skew from A to B is 9.43 ms
Time skew from A to B is 6.19 ms
Time skew from A to B is 7.63 ms
Time skew from A to B is 6.34 ms
Time skew from A to B is 5.43 ms
Time skew from A to B is 7.91 ms
Time skew from A to B is 5.32 ms
Time skew from A to B is 5.79 ms
Time skew from A to B is 5.18 ms

[dome:~/linorobot2_ws] ros2 run handy net_latency A B
[INFO] [1761071660.810864189] [A_delay_node]: Node started: subscribing to A_topic, publishing to B_topic
Time skew from B to A is 172.77 ms
Time skew from B to A is 1.50 ms
Time skew from B to A is 5.03 ms
Time skew from B to A is 2.08 ms
Time skew from B to A is 4.23 ms
Time skew from B to A is 3.10 ms
Time skew from B to A is 2.67 ms
Time skew from B to A is 1.96 ms
Time skew from B to A is 4.39 ms
Time skew from B to A is 2.09 ms
Time skew from B to A is 1.82 ms
Time skew from B to A is 4.13 ms
Time skew from B to A is 4.62 ms

Best,

Pito

Boston Robot Hackers &&
Comp. Sci Faculty, Brandeis University (Emeritus)