RP6conrad
commented
2 years ago I did take a look for the NAV_SAT sentences, but as they have a variable length, It seemed not so easy for me. The baud rate is now 19200 baud, which is fine for the NAV_PVT. Is there a setting in the M8N so that the NAV_SAT is @. Hz, and the @. Hz ? Otherwise, a higher baud rate is necessary. For the moment, I have no plans for logging the NAV_SAT, but as someone will evaluate three GNSS, it could be usefull/necessary.
Greetings, Jan.
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Van: prichterich Verzonden: zaterdag 14 mei 2022 16:18 Aan: RP6conrad/ESP-GPS-Logger CC: Subscribed Onderwerp: [RP6conrad/ESP-GPS-Logger] Support NAV-SAT sentences (Issue #5)
The current firmware only logs NAV-PVT sentences. But for evaluation and debugging, it can often be useful to also have NAV_SAT sentences to see which satellites where used, and what the signal levels (C/N0) were. For example, I recently ordered two BN220 chips which behaved quite differently. One started slower, and often tracked fewer satellites. Looking at signal levels from NAV_SAT sentences showed that the chip with fewer satellites had an average signal strength that was about 3 db lower. I propose to add a config flag that allows logging of NAV_SAT sentences. NAV-SAT sentences can be 4 x larger than NAV-PVT sentences when many satelites are tracked, so transmission rates are an issue. This can be partly addressed by logging NAV-SAT only every 10th cycle, which works fine at 5 Hz. The default should be to not log NAV-SAT sentences, since this information is not normally used to determine speeds. I have modified the local copy of my fork to support NAV_SAT logging, but not pushed the changes to GitHub for various reasons. If anyone else wants to also use NAV-SAT, please let me know, and I'll put the change up. — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you are subscribed to this thread.Message ID: @.***>
The current firmware only logs NAV-PVT sentences. But for evaluation and debugging, it can often be useful to also have NAV_SAT sentences to see which satellites where used, and what the signal levels (C/N0) were. For example, I recently ordered two BN220 chips which behaved quite differently. One started slower, and often tracked fewer satellites. Looking at signal levels from NAV_SAT sentences showed that the chip with fewer satellites had an average signal strength that was about 3 db lower.
I propose to add a config flag that allows logging of NAV_SAT sentences. NAV-SAT sentences can be 4 x larger than NAV-PVT sentences when many satelites are tracked, so transmission rates are an issue. This can be partly addressed by logging NAV-SAT only every 10th cycle, which works fine at 5 Hz. The default should be to not log NAV-SAT sentences, since this information is not normally used to determine speeds.
I have modified the local copy of my fork to support NAV_SAT logging, but not pushed the changes to GitHub for various reasons. If anyone else wants to also use NAV-SAT, please let me know, and I'll put the change up.