GPS operation nRF9160

[SergioT]

Hi:

I already updated the SDK to the first release version V1.0.0 and the unit works well with NB-IoT, UART and SPI. I'd like now to include real GPS data but I can't get the GPS example to work.

I believe GPS should already be working with mfwnrf9160100 version. What am I doing wrong? Do I need an external antenna instead of the board antenna?

Of course I'm trying to get GPS data with the board exposed outside in free air.

It might be important: I am using pca10090 version 0.8.3.

[MJD093]

Can you also give us some more information on why the GPS example isn't working. Can you post the serial port log from the example or the build error if that is what you are experiencing.

[SergioT]

The example compiles and operates as expected. I just added to prj.conf the necessary lines to enable RTT in SES so that I can ee the result of the printk. I added:

CONFIG_PRINTK=y
CONFIG_UART_CONSOLE=n
CONFIG_CONSOLE=y
CONFIG_RTT_CONSOLE=y
CONFIG_HAS_SEGGER_RTT=y
CONFIG_USE_SEGGER_RTT=y

Now I can see on the Debug window:

Tracking: 0 Using: 0 Unhealthy:0
Seconds since last fix 265

Scanning [-]

The number increments every second.

I would expect ot get GPS data after some time, but nothing.

[Carl Richard]

I have access to both 0.8.3 and 0.8.5. Will do a quick GPS test on the 0.8.3 now to check.

[MJD093]

Quicker to tell if you see J6 on the antenna line. That would be the bad antenna circuit

[SergioT]

There is a Murata connector called J6! I checked against 0.8.5 and it is really different.

Can I connect there an external antenna ? If the matching is wrong then it might help...

[SergioT]

From I see in the schematic, the connector is already after the matching, so it will not help.

[MJD093]

It will, any external connector, such as the molex 206640 (which I use on the v0.8.5 DK cause my on-board one flicked off) don't need a matching circuit as they are designed to work off-board. They just need a 50ohm line.

If your board is basically a v0.8.2 GPS board. You have two options really, get a new DK that is of the latest hardware design or buy the murata cable that can connect to that connector and then connect an external antenna that can use the screw antenna connector thing. (seeMurata part no. MXHS83QE3000)

There is a blog post about this somewhere.

[SergioT]

We have a 50 ohm GPS antenna that we developed for another project: We will try it out and  you the result.

[MJD093]

Please see Bjorn's reply in this question, you need that cable, an external antenna and a Bias Tee circuit.

devzone.nordicsemi.com/.../187462

[SergioT]

Our connector doesn't match, so we will need to check it some other day. It will can take a while until we can test...

But thanks for the information. I'll keep on following the development because our own board design is almost ready for prototyping: then we will see if it works or not.

[MJD093]

Sergio, no connector will fit the Murata RF switch connector except their own one. You need the MXHS83QE3000 cable or you can buy the connector end separately and wire stuff to it. I know this because I actually called Murata about this before I swapped my 0.7.0 board for a 0.8.5 board. These are the connections the operator recommended for thier connector.

"Thank you for your phone call yesterday.

MM8130-2600 is our SWF connector type and you can see the recommended probe information as shown below:

 

https://www.murata.com/en-eu/products/productdetail?partno=MM8130-2600 MM8130-2600 Connector

https://www.murata.com/en-eu/products/en-gb/products/productdata/8796821389342/SWN1PR1.pdf?1437968896000 Manual Probe MXHS83QE3000"

EDIT:

Sorry, forgot the other ones were images in the email:

MM126320

MM126056

[Carl Richard]

You were entirely right MJD093! I also got it confirmed from when checking with a Nordic employee; V0.8.3 is V0.8.2 with minor changes.

SergioT, could you mark MJD093's answer as the solution if it was sufficient?