Doudou 2pcs GT-U7 GPS Module Navigation Satellite Positioning Compatible with NEO-6M 51 MCU STM32 High Sensitivity Low Power Consumption High-Precision Positioning Suitable for Vehicles

Wired up to a Helcat V3 device and it "saw" 7 satellites on my windowsill (see attached photo). Be careful with wiring and setting the GPIO pins in the "settings/position" page in iOS (same in Android). I wired VCC to 3v3, RX to Pin 46, TX to Pin 45 and GND to GND. Software/App-wise, I used pin 45 for "GPS Receive GPIO" and pin 46 for "GPS Transmit GPIO" setting. I left the "GPS EN GPO" pin setting to "Unset" and it all worked fabulously! I purchased a case to hold the Helcat and the GPS and a new battery (smaller) but have not assembled as yet. I bought the Helcat V3 on Amazon with the case, battery, antenna and Helcat V3. The GPS will NOT FIT this case, as an FYI. You must use a case designed to fit everything including the GPS.

Great unit for my APRS project. The one from Aliexpress never worked.

Works great on either serial or USB; can be used "hybrid" with the PPS signal and USB for the data delivery which is nice on the Pi series machines which only have one serial port and you might ant that one for a console. One of these plus a "Pi" makes for a very nice and low-cost Stratum 1 NTP time server.

I found these to be quite sensitive. I was able to get a GPS fix in my basement. I'm sure it was pretty coarse! But since you don't expect a fix under those circumstances at all it was quite impressive. Screen shot of satellite reception from my basement in u-center attached. Which reminds me, you can plug these straight into your computer and configure them via u-center which is awesome. Plus it's one of the few GPS modules anywhere that breaks out the PPS signal. I've bought a few now for various projects and will buy more if need be.

I have this wired to a Heltec v3. Just need a switch to prevent it from being powered if the unit is off.