Control of MAGPIO during %XRFTEST

[McRancor]

Hi!

I have an issue with control of the MAGPIO during RFTEST procedures.

The device is using RF Switch (like Thingy91) and I want to perform SNR/Received signal power tests to make sure the matching network is properly working.

I have the following problem. The MAGPIO configuration I can prepare for testing purpose is only valid when the Modem is on (AT+CFUN=1). When I switch the modem off, all the GPIO output drop to low state.

However, the RF SNR test (%XRTEST=3,...) is working reliably only when the modem is offline (AT+CFUN=0). When I'm trying to perform this test while the modem is online, the modem seems to freeze.

The modem fw is 1.1.4.

The question is:

- How to control the MAGPIO when the modem is offline, or how to perform SNR tests when the modem is online?

Any help appreciated!

[Håkon Alseth]

Hi,

 

However, the RF SNR test (%XRTEST=3,...) is working reliably only when the modem is offline (AT+CFUN=0). When I'm trying to perform this test while the modem is online, the modem seems to freeze.

This is correct. The modem must be offline when using these test commands.

- How to control the MAGPIO when the modem is offline, or how to perform SNR tests when the modem is online?

Modem must be in offline mode.

You can use this AT command to set the MAGPIO:

https://infocenter.nordicsemi.com/topic/ref_at_commands/REF/at_commands/sip_pin_configuration/xmagpio_set.html?cp=2_1_5_1_0

 

How are you setting the MAGPIO before issuing AT%XRFTEST command? Can you share the logs from your side?

 

Kind regards,

Håkon

[McRancor]

Hi!

Let me use this example:

The AT host sample started
AT+CFUN=0
OK
AT%XMAGPIO=1,1,1,1,7,600,2100
OK
AT%XRFTEST=3,1,19,8800,-65,1,0
%XRFTEST: -177,-24516
OK

The problem is that this MAGPIO setup is not effective while AT+CFUN=0. All MAGPIO are down. Once I switch the modem on - all MAGPIO go to 1.8V (as expected). Taking the modem off causes all MAGPIO to go back to low (0V). Offline modes etc (AT+CFUN=4, 44 etc.) give the same result.

[Håkon Alseth]

Hi,

 

It seems that your MAGPIO mask is setting for "state" 7 (5th input), which is GPS, but the test parameter is for RX SNR.

Try this mask:

AT%XMAGPIO=1,1,1,7,1,746,803,2,698,746,2,1710,2200,3,849,894,4,894,960,6,803,849,7,1574,1577

 

And see if this enables the GPIOs when issuing the XRFTEST RX mode test.

 

Kind regards,

Håkon

[McRancor]

Hi!

I now checked again everything with a proper oscilloscope setup and I can confirm my original assumption was wrong.

The MAGPIO are not set immediately, however launching the RF test does switch them on, and also they stay on after the test, until the whole setup is relaunched.

Your question about checking GPIO after issuing XRFTEST was the spark, thank you!

[Håkon Alseth]

Hi,

 

Glad to hear that the issue was resolved.

Hope you have a wonderful day!

 

Cheers,

Håkon