MakerFocus 2 Pack GT-U7 GPS Module Satellite Navigation Positioning GPS Receiver Drone Microcontroller Compatible with NEO-6M 51 Microcontroller STM32 Arduino UNO R3 with IPEX Antenna High Sensitivity

I'm using these modules to get accurate time for a Raspberry Pi based clock. For a first test I simply connected one of the modules (the package contains two of them) using a micro-USB cable to a Linux laptop and confirmed that it was working properly.It took a little longer to setup the Raspberry Pi to enable a serial port on GPIO pins 14 & 15 as well as a PPS input on GPIO pin 18. After disconnecting the USB cable and using test leads with mini-clips, I connected the GPS module to the GPIO pins (as well as power) on the Raspberry Pi (I used a Pi 3B this time, but any model should work). Using gpsd I confirmed that I got time and position data from the module as well as the PPS ticks for extra clock precision.The sensitivity of the module is sufficient to get good data from several satellites anywhere within the house (I tried a number of locations to confirm the clock would work there).Unlike GPS modules that I have used in the past (like SiRF-III), these modules have an external antenna (included). Attaching the antenna to the module is a little fiddly (due to the small size of the connector) but the advantage is of course that the antenna can be placed outside of any project case that may otherwise block the reception.The GPS module has a sticker identifying it as a Goouuu GT-U7 but the software recognized it as a uBlox compatible module (given the low price it is either a uBlox product from an older generation or a 3rd-party clone). I did not do any testing regarding location accuracy or the speed of obtaining a 3D-fix since those are not relevant for my purpose.I'll keep the 2nd module for a future project.I'm perfectly happy with this purchase.

Overall; Recommended.Purchased to add GPS to a Heltec V3 LoRa device running Meshtastic. Hookup instructions can be found on the Meshtastic website and several other locations (Amazon Terms of Use prohibit providing the links, use your fav search engine to find them). Remember to redefine the GPIO pins for RXD (GPS_RX_PIN 45) and TXD (GPS_TX_PIN 46) signals. I didn't bother with the GPS_Enable pin for now, manually disconnecting the VCC header (may add a switch or the switching transistor mod described on the Meshtasitc site later).Pinout on the GPS board is slightly different than the examples I found, but the labeling is correct. I used the headers provided with the Heltec and with the GPS and a set of breadboard jumpers I already had for wiring, this simplifies disconnecting the GPS if not needed. The headers complicate packaging if you want to use one of the case designs on 3D printing sites or available for purchase. Of course, you can solder direct-wire for a less bulky assembly.The antenna is separate and comes with an IPEX connector to attach to the GPS board. The antenna can be mounted to maximize GPS signal reception while the GPS receiver can be mounted forGPS performance is good, and it picks up signals inside my house better than a USB-based GPS I use for 2M VHF AFSK APRS. The additional power consumption is not bad, a few days of tests suggests I can get a bit over 24 hours of operation with a 3000 mAH battery. The Heltec V3 is not ultra low power consumption, so I would expect much longer operation with a less power-hungry LoRa device.

DARK BLACK MODEL:This is the puck one with the tiny DuPont connectors. The connectors are not for 2.54 DuPont pins but if you shove hard enough they’ll go in and make good contact.It has a good receiver and low power (20ma). It gets a fix about as quickly as the bare board model but does it in places in my house where none of my other units can (the ‘black’ ones which are just the board and antenna).It is 38400 baud by default, that can be changed via i2c or with the ublox windows app. Ublox has an i2c driver on github but it’s too big for a nanos 328p memory.So I use it at 38400 on the nano’s internal uart . You have to set the Serial baud rate to 38400 and then disconnect the wire between the gps and the uart RxD (pin 2) to download programs. You can still print debug statements to the USB port but they’re going to have be at 38k. This model emits messages much faster than the once per second of the black model, at least 5x, maybe more.I have had it in hand for a couple of years but just started using it. During my first day I see it producing $GNRMC messages as opposed to the $GPRMC messages I am used to from the other units in this ad. The GN messages are probably from GLONASS but might just be the way this company handles supporting both GPS and GLONASS. In any case GNRMC messages are formatted the same as GPRMC. There are plenty of other messages but I only care about RMC ones.It updates 5 times per second but the first of those may not come out until the end of the second. The latency seems to slew slowly from being early to being late. This results in the time being accurate sometimes and 1-second slow later.BLACK MODEL:Update: one of my nanos was only putting out 4.2v on the 5v pin and that caused many problems includingvery poor reception by this gps. If yours acts up check the voltage it’s getting.Update: For my clocks I finally wrote my own nmea parser that only looks at the RMC messages. TinyGPS hides the actual message type from you, it waits until the age and error flags are all proper before it hands data off to you and it takes time extracting a lot of stuff I don’t care about. I have things to get done and TinyGPS was getting in the way.20ma draw.First (cold) start under a tin roof at 2000ft above sea level approx 10 min but may not happen at all until satellite view improves.Warm start 10min later still under tin but against outside wooden wall is 5 seconds. 12 sats in view and 9 tracked.‘Tepid’ start after being off overnight is about 5-10 seconds in the same conditions to emit time but getting the date takes maybe another 5 seconds.Sentences with time appear as soon as the first sat is in view. (Nice for use as a clock source).