Greetings, first post here. I’m the senior GIS admin for a small municipality in FL and I’m doing some research on building an RTK device. I’ve built some extensive code that uses a cheapo NEO-M6, runs on an M5Stack Tab5 and records lat, long and altitude on an SD card. And that works fabulously - albeit not very accurate of course with the NEO-M6. I have an FPRN account with FDOT and am able to successfully receive correction packets from a nearby tower via a Wifi hotspot on my phone and the Tab5 – even though the NEO-M6 can’t do anything with the data. So now, I’m looking to update my code to work with your ZED-F9P for better accuracy. I ordered the ZED-F9P from Amazon and am just a little confused about the voltage requirements. The description says it can accept both 5V and 3.3V, but only operates on 3.3v logic. OK, understood. But I have read that supplying 5V to it via qwiic cable to the input will fry the module. I really would love to use a qwiic cable between the ZED-F9P and the Tab5 grove port, as my current setup does this. But I have read that doing so will fry the module, as the voltage regulator only is between the 5V pad or USB and not the qwiic cable. Is this true? Cutting the 5v line on the qwiic cable and then using USB to power it as I’ve also read seems very clunky to me. I’d really like to simply use the cable. Is it true that using qwiic cable from grove port will destroy the board? Any assistance would be GREATLY appreciated. Oh, and BTW – Joelle was very friendly and directed me here from Amazon. Thanks again!
Howdy!
Your research is correct, supplying 5v to the qwiic port will inject 5v downstream of the F9P’s regulator (it ties directly to the 3v3 rail)
and the Tab5 does output 5v on its grove port
While seemingly clunky I do think cutting the qwiic/grove cable’s power wire and supplying power via usb or 5v pin (you could cut the qwiic cable and use its end to connect to the 5v PTH hole, as long as it is cut long enough) is probably the easiest/most practical way to get goin’
The other methods would be swapping to a different MCU, use a logic level shifter, or to not use the qwiic port (you could wire the Tab5 to the F9P’s UART instead)
Thanks very much for the fast reply! And for the detailed explanation. I really appreciate it, and the options you provided will give me some things to try. I’m looking forward to getting this working. Thanks again, cheers!