If I wanted to connect my handheld Garmin GPS (instead of the EM406 provided with the logger) to the SFE GPS Logger V2.4 (each device running on a separate power supply), would it be sufficient to simply connect the GND, TX, and RX pins from the Garmin to the associated GND, TXD1, and RXD1 pins on the SFE Logger? No connection would be made between the Garmin and the V+ pin on the SFE Logger.
Are there any concerns I should have, or precautions I should take, with this scenario?
The SFE Logger schematic can be found here:
http://www.sparkfun.com/datasheets/GPS/ ... _4_sch.PDF