GPS data collection using UART6 of STM32F411VEH6

[GBISW.1]

Hello,

I am using NEO M8U as GPS sensor in our custom board.

GPS data is has to be collected using UART6 of MCU(STM32F411VEH6). Signal names in schematics as (MCU_GNSS_UART_TX and MCU_GNSS_UART_RX).

Code has been attached . I am unable to receive data. I am suspecting some configuration issue of UART6.

Kindly suggest.

Regards,

GBiswal

[waclawek.jan]

> I am unable to receive data.

Make sure data are arriving at the pin you've chosen, by measuring using oscilloscope directly on the pin.

Read out and check content of UART and relevant GPIO registers.

Make sure clocks/baudrate are set appropriately. The easiest way to accomplish that is to Tx from the same UART and observe using oscilloscope/logic analyzer.

JW

[Tesla DeLorean]

Please try to crop images appropriately, this was unusable on my android

Don't pull RESETn LOW, also don't drive it with a Push-Pull Driver. Should be pulled high, and clamped low with open-drain if required.

You could also try disconnecting RESET if the part isn't starting properly.

RX/TX look good. Should be able to scope data bursts on NEO-M8U TX pin, defaults should be 9600 8N1 with a grouping of NMEA sentences.

[GBISW.1]

Thanks for suggestion.

Actually I am not using any GPIO out for RESETn to NEO M8U .

Now I have added a GPIO out pin (PA5) in STM32, which is used as RESETn and made output level as "High" as shown in figure.

After that I am able to receive some data. But actual datas are missing.

output file is also attached.

Kindly suggest.

Regards,

GBiswal

[Tesla DeLorean · Accepted solution]

That's kind of indicative of not having a fix.

You might expect it to take 30-45 second to get a fix if the antenna is working properly, and it has a clear view of the sky.

What did I say about RESET using a Push-Pull driver?

[GBISW.1]

Thanks for helping.

In a clear view of sky I am able to receive GPS data.

After fetching from NMEA sentence(GNGLL) the data is showing some 30 KM far from my location.

Output file attached.

Regards,

GBiswal

[Tesla DeLorean]

That would be more indicative of you not translating the degrees/minutes format use by NMEA into decimal degrees properly.​

[GBISW.1]

Thanks.

Yes its my mistake. I was putting directly NMEA data in google map.

After converting minute to degree I am getting 4m accuracy.

Regards,

GBiswal