ST87M01 RF_AUX to GNSS_ANT

[JustTinker]

Hi,

I have a board design with the ST87M01-1301 that I am trying to bring up. The ST87M01 boots and I can control the device from the ST 87Mxx OM GUI tool, no issues with any of that.

I am trying to get the GNSS working with a single antenna as shown in the data sheet and the EVKIT. The board is routed with RF_AUX (pin 33) connected to GNSS_ANT (pin 31), all per the guidelines. A passive GPS antenna is connected at the RF_ANT (pin 35)

Is there an AT command that switches the RF_AUX On/Off to connect to the GNSS_ANT pin, or is the RF_AUX o/p always available? I have not been able to find this information in any of the ST87M01 documentation.

At the moment my board is never able to get a GNSS fix and I want to be sure I have not missed a critical configuration AT command. The GUI continually outputs #GNSSFIX: 5.

Thank you in advance for any comments or guidance. 

JT

[Didier HERROUIN]

Dear JustTInker,

Your connection is correct, you do not need a AT command to enable the RF_AUX.

I have attached the GNSS Application Note in case you don't have it already (it should be in the GUI folder after GUI installation), it may help. The GNSS fix must be done with the antenna placed outside a building.

If I well understand, you don't use an eval kit but your own design. Please check that you have really received the 1301 chipset version.

Regards,