| name | drive-satpulsed-from-log |
| description | Drive a test satpulsed instance from a recorded packet log, with no GPS hardware, by replaying the log through a FIFO with original packet pacing. Use to exercise the full scan/decode/event pipeline or the web interface from a capture. |
| user-invocable | true |
| allowed-tools | Read, Bash, Glob, Grep, Write, Edit, AskUserQuestion |
Drive satpulsed from a packet log
Replay a recorded JSONL packet log into satpulsed through a FIFO, so the daemon runs its normal serial-input path with no GPS hardware attached. Useful for testing the web interface, or verifying the scan/decode/event pipeline, from a captured log.
Setup
Use the satpulsed-test-instance skill to build and configure the daemon, with these specifics:
- Set
[serial] device to a FIFO path with a sensible basename. The basename becomes the log basename (/tmp/fifo0 produces event.fifo0.jsonl), so avoid a confusing name.
- Enable
[[http]] on a non-2000 port if you want the web interface.
- The event log (
[log] event = true) is optional. Enable it to confirm the replay pipeline is producing events; skip it if you only care about the web interface. The event log is always a good way to check the pipeline is working, but it is not always needed.
Create the FIFO and start satpulsed
mkfifo /tmp/fifo0
Start satpulsed in the background (per the setup skill) with device = "/tmp/fifo0". satpulsed opens the FIFO O_RDWR, so the order does not matter: if pack starts first its write will block until the daemon opens the FIFO for reading.
Replay the log
Pick a packet log, for example /var/log/satpulse/packet.ttyACM0.jsonl, or a smaller test fixture. Replay it into the FIFO in the background:
out/$ARCH/satpulsetool pack --realtime \
/var/log/satpulse/packet.ttyACM0.jsonl > /tmp/fifo0
--realtime reproduces the original inter-packet pacing (about 1 Hz for typical logs). Without it, pack writes as fast as the daemon reads.pack writes only packets received from the receiver; out:true and non-packet metadata entries are skipped automatically.- Use
--tag/--msg to replay only some packets. See satpulsetool-pack(1).
Verify
- Web interface:
curl http://localhost:2001/position should return a position that advances as the replay runs, or open the GUI at http://localhost:2001/.
- Pipeline (if the event log is enabled): the event log should grow and contain the expected event types (
time, posGeo, velGeo, navEpoch, satellites, ...).
Teardown
Stop the daemon per the setup skill. Because the daemon holds the FIFO O_RDWR, it does not exit when pack finishes, so you must stop it explicitly. Once the daemon is gone, pack exits on SIGPIPE (or kill it).
