drive-satpulsed-from-log

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).