AdafruitUltimate GPS Breakout 66 Channel Module with 10Hz Updates Version 3, Blue

Setting up with Raspberry Pi 4B and DietPi with Tunerstudio for Speedometer of PiDash. VIN (GPS) to 3.3V on Pi, GND (GPS) to ground on Pi, RX (GPS) to TX on Pi, TX (GPS) to RX on Pi. Use DietPi-Config / option 4 : Advanced Options / Serial/UART to make sure ttyS0 console is off and ttyS0 (mini UART) device is on. I used CuteCom to set the baud to 115200 and refresh rate to 10Hz. Default GPS unit is 9600 baud and 1Hz. Start with CuteCom set to 9600 and send $PMTK251,115200*1F to change baud. Change CuteCom to 115200 baud and send $PMTK220,100*2F to change refresh to 10Hz. Make sure you have the battery backup installed in the GPS or else it will revert back when powered off. In Tunerstudio Beta (there was a problem with GPS which I don't know is fixed in the stable release yet) use Communications/ GPS Configuration to set up. See pic for details. I am using it with an external antenna so I can't comment on the internal one.

I bought this for a GPS guided robot project using an Arduino. Works well and gets a lock with-in a minute even in doors.Some tips if you are going to use this on an Arduino:- Baud rate is 9600- You really only need to hook up the Tx pin to the Arduino, RPi or PC. (I don't know what commands you can send to it anyway)- Use the "TinyGps" library in your project [...] to parse the NMEA strings from this GPS.- No extra serial port? No problem! Use the "SoftwareSerial" library that is part of the Arduino IDE ... with that you can assign any of the Arduino pins to be an Rx/Tx pair.- I soldered header pins to the bottom of the board so that the GPS antenna can be free and clear of any wires.5 stars because it does the job!

This little GPS works great. I found sample code on the Adafruit website and had it up and running in a couple of minutes. After a minute or two it picked up GPS signals *inside* my house with just the built-in antenna. I put the coordinates into Google maps and that put me in my garage, which is on the other end of the house. I don't know if Google maps are off or the GPS coords were off but it's still pretty darned good for being an indoors reading, especially considering my Garmin car GPS won't get a signal inside my home.Seller was very cool by e-mailing that it wouldn't arrive on time (Xmas week order) and gave me the opportunity to cancel the order if the delivery delay was a problem.

This is an extremely sensitive serial gps unit. Has a PPS output pin as well. Works on anything from +3.3v to +5v as well. Great if you're using it with one of the many arm based boards. I bought an external antenna, but even before that, I was noticing it getting a fix indoors across the room from two windows with the blinds shut. Please note the little red light flashes fast when acquiring, then very slowly when it gets a fix. Doesn't turn green or anything, just starts flashing very slowly. If you're good with a small soldering iron, mount the battery clip on the back and put a battery in. It'll lock much faster after that.

UPDATE:I've had time to continue to collect various data points and program this and a NEO-6M (both in CircuitPython/Python and Arduino's C/C++. I've decided the Adafruit Ultimate GPS is decent for most beginner projects (Adafruit's goal as I've read from them....I'm certainly a huge fan!).In Western Washington, it closely meets its' spec of being within 3 meters when I'm in a cul-de-sac without trees or buildings for 10-12 meters. I had one-time, single position under 2 meters, but this is a single data point from many. Generally, it seems to put me about 6-10 meters from where I actually am for this region.In the Great Flat Plains of Kansas, where the only thing in sight is the edge of the Earth in all directions, it is better being within 2 meters.Taking the same positions from my NEO-6M, the NEO-6M just puts me spot on (<1m) with every data point in Kansas and within 2-3 meter's from some of the difficult places in Western Washington.Having spent several hours programming both, I think the CircuitPython makes the Ultimate GPS a super product to get going. There might be better accurate data from this device as NMEA sentence it pulls data from, the GPS position is slightly different than at least one other sentence. This might be why the NEO-6M presents better, the CircuitPython pulls the information from a different NMEA sentence on the NEO-6M. My to-do list is to compare the sentence information from the same chip.Original Review:This took a couple hours to get setup using CircuitPython on a Feather M0 Basic.It doesn't pick any signal up inside (unlike NEO-6M I also purchased). Once outside, it took a while to pick up signal, but was extremely stable in the location values it produced (where as the NEO-6M picked up immediately, although its' values had some flutter to them).I'm looking forward to using both.

Having a battery on-board helps greatly reduce the time to acquiring satellites.20 minutes (indoors) w/o, and 30 seconds (indoors) with the battery already in place.Performs nicely.

I'm not exactly a ninja with a soldering iron, but this kit (OK, it's just a matter of soldering the pins on, but like I said, I'm no ninja with the iron) was easy to assemble.The manufacturer's website has a really good set of documentation for both Pi and Arduino connections, and I got mine online in a minimal amount of time via a breadboard.On warning (not this components fault at all); make sure you get the right pigtail to connect it to an external antenna. Adafruit has the right one listed, and you can find it here on Amazon too.