Just purchased a Navio+ and was wondering about eventually using the RTKLIB on my RPi2 with it for more precise positioning.
The original Navio (Navio Raw) came with a NEO-6T Ublox GPS receiver chip that allowed for the raw pseudo range data to be output straight off the board. The “better” Navio+ has a NEO-M8N chip` that DOES NOT output the raw pseudo range data (or timing, “T”) right off the chip.
NEO-M8N does not support raw-data officially. However, it is known that some F/W version can be configured to output raw-data as TRK-MEAS and TRK-SFRBX messages. I confirmed it by F/W version 2.01. The latest RTKLIB (2.4.2 p11) can also handle such messages. For details, refer the following material.
I found some limitation by M8N compared to M8T.
(1) Raw message can be used only with 1 Hz (NG with 5 Hz).
(2) Only GPS ambiguities can be resolved (NG for GLONASS or BeiDou)
Again, these are not supported by u-blox formally. Other F/W versions may not support them.
So basically… Navio stripped off the ability to do RTKLIB natively on the Navio+ board, put it on their REACH module, then charge you 5 times more? Whats even more funny is that originally they had extra NEO-6T modules which they were put on a usb dongle for $50… but now REACH costs $570?
I’ll stop complaining now, but here’s my request to please put the timing enabled ublox chips BACK on the Navio? Call it Navio 2.0??
(I almost agree with @jstromsoe. While Emlid is a company and it has to make money and I have nothing against this I think there was a communication error with the name “Navio+”, maybe putting extensively that M8N has not the same performances of NEO-6T in terms of raw messages and RTK, IMHO)
I think that there is some misunderstanding here. Navio did not strip off anything. It was made to be used as a platform for APM, yes we had a RAW version with NEO-6T, but it was not very popular. It does not make sense to put M8T in each Navio+ as it will increase price significantly for everyone.
Reach does not cost $570, this is the price for 2 Reach RTK + 2 Tallysman antennas. Also, each Reach includes Intel Edison processing module with Wi-Fi and BT. Single unit is just 225$.
@keithc You can desolder M8N and put M8T in its place, they are compatible, however that will void your warranty.