# MacBook Pro 2016 and Dual GPS-160A Logging

OK, this is a bit mysterious, but if you are trying to do data recording from the Mac, it is super convenient to be able have a GPS log with time stamps along with your video. While the Mac does capture time super well, what about location. Here is one way to do it (note this is an old post from 2017, but was lost in another blog, so here it is for completeness

1. Get a Dual GPS-160A. This allows up to five devices to connect via Bluetooth to it. I've tried to make it work with GPS Sharing application that broadcasts on the network but that doesn't seem to work.
2. Next do a bluetooth connection from macOS Sierra. this is super frustrating because many times, you will never see a new Bluetooth device. Discovery seems very flaky. I have tried rebooting the machine and turning on and off the system, but you just have to keep trying.
3. When you do see it, you click on System Preferences/Bluetooth and look at the list of unpaired. Eventually you will see something with the GPS-160A prefix. Note that by default, MacOS assumes you want the Bluetooth Serial Port Profile installed and creates a pseudo tty for you.
4. Now to see if you have a live connection, you will notice that the blue LED on the GPS does not blink nor does it say connected. The system remains unconnected unless you request data from it. There should be a /dev/tty/ entry with something like /dev/cu.GPS-160A as the prefix. To verify it that it works start terminal and run screen /dev/cu.GPS-160A* and you should now see the LED go solid and then a whole stream of ASCII strings burst out. Look for ones that have the prefix GPGSA which means a fix. These are each NMEA sentences
5. To see if this works try running screen /dev/cu.GPS-160A* and then hit enter, you should see a lot of these previews. To get out, you type CTRL-A and then a k to kill the last session.

Now the really hard part is to find some Mac software that can log NMEA strings in a decent format. The iPhone and Android applications work really well, but this is very unusual these days to have a PC with GPS information:

1. LoadMyTracks. This has the most hits, but doesn't work with the GPS-160.
2. MacGPSPro. This is $30 and says it works with anything that speaks NMEA on a serial port, so we will see 3. BT-747. This only works with a certain chipset (not the one in the GPS-160 apparently). 4. MacGPSPro. It does cost$30, but it is worth it if you doing collection. This one finally did the trick, set it in Preferences to the GPS160 port and then to 38400 baud for Bluetooth (I didn't know that one) and then just NMEA as the format. It will take some time. Then you can see the location Real Time/Display Current GPS Readings to make sure it works. It will take about 30 seconds for the connection to get made and you will see a solid dot and will come up with a spurious error message saying try to reset and then it works and then to log while reading set it to Real-Time/Collect Current Readings into a File and then Real-Time/Show Position on Google Maps