Minimal debugging output is generated by default. You can increase the output in different ways. Easiest is to increase debug level on the fly with the running sensorfwd. Output can be seen with
journalctl -af
Dynamically increase debug level from command line:
devel-su
kill -USR1 \`pgrep sensorfwd\`
twice for highest output level.
For status report:
devel-su
kill -USR2 \`pgrep sensorfwd\`
Static increase debugging level
If running from systemd, edit /lib/systemd/system/sensorfwd.service and change --log-level=warning to --log-level=test or do:
devel-su
sed -i -e 's/--log-level=warning/--log-level=test/' /lib/systemd/system/sensorfwd.service
then run
devel-su
systemctl daemon-reload
Then reboot or
systemctl restart sensorfwd