I just ordered a Grove GPS based on the Ublox Neo-6M. While waiting for Grove GPS to arrive, I have been reviewing the board and schematic, along with the Ublox documentation. As i understand the Neo-6M, there are a few great features that can be added to the Grove board without to much effort or expense.
The procedures for adding the improvements that I’m suggesting is described in detail in the Ublox Hardware Integration Manual.
Battery Backup option V_BCKP (pin 22) - Instead of forcing the V_BCKP to ground, bring it out to a strapping pad or header so that an optional 3.3v backup battery can be connected - or just shorted if no battery backup is desired. The cost of this mod is near zero and is well worth it have the option of a 3.3v standby battery to allow GPS hot/warm start .
Add an EEPROM to the unused I2C port (pins 18, 19) - As described in the Hardware Integration Manual, the Neo-6M is able to persistently store it’s configuration in a 4k byte EEPROM connected to the I2C bus and restore it when the Neo-6 is powered up. The cost of a 24AA32A SOT-23 EEPROM is about $0.30 or less - well worth it to get the Ublox GPS restarted quickly and without any, or minimal, re-programming and re-initialization.
Add USB connectivity (pins 5,6,7)- By adding a 3.3v LRO and ESD diode protection, the USB port can be exposed to a 4 pin header. This will allow for optional direct USB connectivity at a cost < $1.00. for the 3.3v LDO and dual ESD chip.
Expose the SPI ports (pins 14,15,16) - Add a 4 pin header to expose the SPI interface, protect with an ESD chip.
Protect all external i/o ports with ESD chips - We don’t need to risk zapping the GPS when ESD diode chips are so inexpensive.
I do know that space is tight on the current board footprint. But by shifting some components and/or mounting them on both sides of the board, these mods should be possible.