Trouble reading GPS from "NEO-6" module

[Ioannis]

What is the output of GPS? TTL or RS232 level?

You have to use the appropriate. If the GPS has true (that is non inverting) TTL output then connect it directly to the PIC input. If it has a RS232 level then you may damage the PIC input and you have to use a converter from RS232 to TTL.

Ioannis

[CuriousOne]

https://www.addicore.com/products/ne...le-with-eeprom

I just read about 3.3V, will try it now...

[CuriousOne]

No change...

But it does output something like which starts with $GNGAO (changing numbers)

[Ioannis]

The module can tolerate up to 6V on Vdd but the Tx/Rx are 3.6 max. This can be a problem if your PIC is supplied at 5V.

The site you posted says:

" To use with a 5V logic device, such as an Arduino, we suggest level shifting the 5V TX signal using one of the following:
Two 1N4148 diodes in series between the TX pin on your 5V device and the RX pin on this GPS module (will drop voltage to ~3.6V)"

Page 8 of GPS datasheet
"1.8 Raw data
Raw data output is supported at an update rate of 5 Hz on the NEO-6T and NEO-6P. The UBX-RXM-RAW
message includes carrier phase with half-cycle ambiguity resolved, code phase and Doppler measurements,
which can be used in external applications that offer precision positioning, real-time kinematics (RTK) and
attitude sensing."

Note that the module can output 3 protocols, NMEA, UBX and RTCM. See 1.15 section for setting protocol. If you want NMEA make sure that you have configured it propelry, that is CFG_COM0 and CFG_COM1 pins at logic 1.

Also I would set CFG_GPS0 at logic 1 also for maximum performance and NO sleep.

Ioannis

[CuriousOne]

I connected it directly to the PC via USB<>TTL serial adapter and with own software, u-center, it works fine - locks satellites, displays position, displays time.
As I understand, I need to care for this line only:

$GNZDA,202437.000,21,07,2024,,*48

So I believe that issues are related with maybe voltage levels, I'll try to add some resistor dividers tomorrow and will check again.

[CuriousOne]

Fixed!

Issue was with AI error - it suggested GPRMC as sequence to wait, but in real life it is GNRMC.
Fixed it and everything works fine, even with software serial.