- Tue Mar 28, 2006 7:21 am
#11582
Hello,
Deeply impressed with the Lassen IQ logger - great job folks! Have never ever before picked a high tech gadget out of the mailing box and had it working so quickly.
But, all my GPSnnn.TXT files (and any other file system item generated by these things) appear to have been last updated on 04 March 2005... Hope you can pick up the correct date and time from the GPS and put a real datetime in the file system? I suppose I can put the Lassen IQ unit on the USB interface module, and there reprogram it to include other NMEA messages, some of which also include the date, but in the default version files easily get mixed up... Could also be a neat trick to include a unit identifier (user programmable?) in the file names?
I understand from other posts that the LED blinks during the time it takes to write a record to the SD-card. This may be convenient for many, but I would like to see a blink for the exact time of the 1s GPS pulse, and have that pulse available somewhere. If the receiver does not currently have a valid fix, the internal logger/GPS clock or counter will drift, and the pulses will not be accurate - in this case I would hope to see a double blink or some other warning (the logger will save records, but with missing or low quality content?).
Have tested three logger units in parallel - the blinks appear to be in sync when the units are stationary with a good view of the sky. When driving through a tunnel, the units quickly come out of sync (may drift visibly out of sync and back into near sync in a matter of 5-10 seconds). In order to synchronize readings from several units (being anywhere from 10 cm to 10s of kilometers apart), it would be nice to know that the 1s pulse is used, and that the log record represents data taken exactly at each one second trigger (I understand that part of the GPS system spec is that these pulses appear simultaneously all over the globe?).
Will it be possible to upgrade firmware on current modules (perhaps with a little soldering, etc.)?
Best regards
Terje
Deeply impressed with the Lassen IQ logger - great job folks! Have never ever before picked a high tech gadget out of the mailing box and had it working so quickly.
But, all my GPSnnn.TXT files (and any other file system item generated by these things) appear to have been last updated on 04 March 2005... Hope you can pick up the correct date and time from the GPS and put a real datetime in the file system? I suppose I can put the Lassen IQ unit on the USB interface module, and there reprogram it to include other NMEA messages, some of which also include the date, but in the default version files easily get mixed up... Could also be a neat trick to include a unit identifier (user programmable?) in the file names?
I understand from other posts that the LED blinks during the time it takes to write a record to the SD-card. This may be convenient for many, but I would like to see a blink for the exact time of the 1s GPS pulse, and have that pulse available somewhere. If the receiver does not currently have a valid fix, the internal logger/GPS clock or counter will drift, and the pulses will not be accurate - in this case I would hope to see a double blink or some other warning (the logger will save records, but with missing or low quality content?).
Have tested three logger units in parallel - the blinks appear to be in sync when the units are stationary with a good view of the sky. When driving through a tunnel, the units quickly come out of sync (may drift visibly out of sync and back into near sync in a matter of 5-10 seconds). In order to synchronize readings from several units (being anywhere from 10 cm to 10s of kilometers apart), it would be nice to know that the 1s pulse is used, and that the log record represents data taken exactly at each one second trigger (I understand that part of the GPS system spec is that these pulses appear simultaneously all over the globe?).
Will it be possible to upgrade firmware on current modules (perhaps with a little soldering, etc.)?
Best regards
Terje