Is there any way to filter bad values coming from NMEA2k? AIS GPS puts out garbage until it gets a fix.

[bradharley]

I'm wondering if there is any way to filter/discard bogus position data on N2k? My AIS (Vesper Marine XB-8000) puts out garbage upon power on until it gets a fix. I can clean it up, but it would be nice to be able to filter known bad values. I sometimes get Longitude at 600+, which is humorous. Example from influx log...

time 1m_jsonValue 1m_lat 1m_lon context source

---

1681393080000000000 {"longitude":-1e-7,"latitude":-1e-7} -1e-7 -1e-7 vessels.urn:mrn:imo:mmsi:367763630 Actisense.c078c3003f02a0b3
1682086680000000000 {"longitude":-9.8304e-11,"latitude":0.00201863462912} 0.00201863462912 -9.8304e-11 vessels.urn:mrn:imo:mmsi:367763630 Actisense.c078c3003f02a0b3
1727040180000000000 {"longitude":-41.2975088,"latitude":-159.9143928} -159.9143928 -41.2975088 vessels.urn:mrn:imo:mmsi:367763630 Actisense.c0328200222363ad
1732819920000000000 {"longitude":-179.3489905,"latitude":-121.801164} -121.801164 -179.3489905 vessels.urn:mrn:imo:mmsi:367763630 Actisense.c0328200222363ad
1734647100000000000 {"longitude":-194.1594355,"latitude":-55.6559096} -55.6559096 -194.1594355 vessels.urn:mrn:imo:mmsi:367763630 Actisense.a0be00f835403b08
1744650000000000000 {"longitude":-1e-7,"latitude":-1e-7} -1e-7 -1e-7 vessels.urn:mrn:imo:mmsi:367763630 Actisense.c078c3003f02a0b3
1749243720000000000 {"longitude":-1e-7,"latitude":-1e-7} -1e-7 -1e-7 vessels.urn:mrn:imo:mmsi:367763630 Actisense.c078c3003f02a0b3

If not, I'll just plug back in my old GPS. :)

[sbender9]

You can use node-red to filter it

[sbender9]

This is an example flow that filters out bogus wind data.

[{"id":"95042388.f05db8","type":"signalk-input-handler","z":"f8b48a68.917e28","name":"Wind Speed","context":"vessels.self","path":"environment.wind.speedApparent","source":"","x":140,"y":240,"wires":[["6367f13d.a4938"]]},{"id":"d6ac2711.cdda9","type":"signalk-input-handler-next","z":"f8b48a68.917e28","name":"","x":630,"y":240,"wires":[]},{"id":"6367f13d.a4938","type":"switch","z":"f8b48a68.917e28","name":"> 100 knots","property":"payload","propertyType":"msg","rules":[{"t":"lt","v":"194.384","vt":"num"}],"checkall":"true","repair":false,"outputs":1,"x":380,"y":240,"wires":[["d6ac2711.cdda9"]]}]

[bradharley]

Thanks Scott! I didn't know about the inputfilter node.... thanks!

…

On Sun, Jun 15, 2025, at 11:21 AM, Scott Bender wrote: You can use node-red to filter it — Reply to this email directly, view it on GitHub <#183 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAEHFXC7FUADXRVPLHR37AL3DWTSLAVCNFSM6AAAAAB7LQDE7OVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTGNBXGU2TOMA>. You are receiving this because you authored the thread.Message ID: ***@***.***>