Might have fried NEO-6M GPS?

I am using an Uno, connected Vin to a 12v lead acid battery (no car involved). That is a little outside the recommended voltage I know, but it is simple and has worked okay for most of my experiments.
For this experiment I connected a NEO-6M GPS, on an XBee shield, to the 3.3v arduino output, along with the proper ground and I used software serial on pins 11 and 12 for RX & TX pin connections etc. All of these things I learned from this forum, thank you all. I got good data sent to my computer monitor too.

Then I decided to send configuration data to the gps. That was a bad idea, because I forgot to consider that the gps is 3.3v and the serial TX to it was coming from an arduino running at 5v. It is interesting to notice that the 3.3v RX input from the gps was okay with Arduino, but not the other way around. I learned that I should have put a 10K resistor in the wire from Arduino TX to Neo RX. The result seems to be that the gps doesn't find any satellites anymore, but it still outputs the 6 $GP... strings every second, but with blanks, zeros, and nines, like it does indoors.

Has anyone else made this mistake too? Am I evaluating the results logically?

I am going to close out this thread with a few new clues, but the GPS is still not receiving satellite data. First, a little more detail on the GPS: It is GPS Bee V1.0 from ElecFreaks.com. There is no memory or battery or USB connection.
Lessons learned: 1) No, it’s not fried. It still outputs strings, and it accepts configuration requests. 2) The pins marked SCL and SDA are “for configuration only” but that does not mean that they are the only pins that can be used for configuration. The pin marked GPS_RX, which I connected to the Arduino software serial pin TX, will also accept configuration! 3) Although the GPS shield is running on 3.3v supplied by the Arduino, it still accepts configuration transmissions from the Arduino, which are 5v. Nonetheless, here is how I created a level adjuster: from Arduino pin 11 (sofwareserial TX) , through a 2.2K resistor to a 4.6K resistor to ground. Then from between the resistors, (now 66% of the voltage on pin 11) to the GPS RX.
Attached is the sketch for your enjoyment. It does the expected, which is to change the output frequency from 1 Hz to 5 Hz. It is simple, therefore, to verify that it works. This shield has no memory, so it always goes back to normal upon power interruption. In the sketch, other hardware is mentioned, I always include a complete pin out for the Arduino in my sketches so that I can verify the hardware before I upload a sketch.

configureGPS.ino (5.36 KB)

If you can't get it to work, it is probably fried (perhaps only the GPS receiver part).

We have all done something similar. Buy a new one and write off the cost to "lesson learned".

jremington:
If you can’t get it to work, it is probably fried (perhaps only the GPS receiver part).

We have all done something similar. Buy a new one and write off the cost to “lesson learned”.

Indeed, we have! more than once.

Paul