RAK3172-SIP trasmit problem

I purchased 2 rak3172-sip powered them up and tried the at commands. unfortunately I immediately found 2 problems:

  1. when I try to read VBAT it returns 0.
  2. When I try to do Join the device communicates with a very weak signal even though the gateway is a few meters away.
    The firmware Is the last version of RUI, ed the problem Is the same with the firmware insider the module, the band Is EU868.

HI @Egodomenico ,

For the VBAT, can you please confirm what is connected on PIN_A0? This is GPIO PB3.

On the weak signal, what is the antenna used with RAK3172-SiP?

The antenna is the one supplied by RAK with the module.

I connect PB3 to VCC but
03:29.658: AT+BAT=?
AT+BAT=0.000000
OK
and
When I run JOIN the consumption is around 11mA
AT+JOIN=1:0:10:8
OK
The signal is very low, barely perceptible from the gateway
Other information
07:48.348: AT+VER=?
AT+VER=RUI_3.5.3_RAK3272-SiP
OK
AT+CLIVE: Command not found!!
08:25.981: AT+APIVER=?
AT+APIVER=3.2.2
OK
08:44.322: AT+HWMODEL=?
AT+HWMODEL=rak3172-sip
OK
08:51.815: AT+HWID=?
AT+HWID=stm32wle5xx
OK
10:47.685: AT+CLIVER=?
AT+CLIVER=1.5.7
OK
AT+SYSV=3.316113
OK

the antenna is the one supplied by RakWireless with the RAK3272-SiP and the configured band is EU868

Have you used the iPex connector for the antenna ? If so are you sure it’s properly plugged (these connectors are very fragile and very easy to destroy if you don’t plug them properly !

Hi @vincen @Egodomenico ,

There are firmware bugs introduced specifically to RAK3172-SiP on RUI3 v3.5.3 which affects signal strength.

This is already addressed on our issue/bug tracking system. If really critical do to some verifications on signal levels, you can try to do firmware downgrade temporarily which has no issue on RSSI levels for RAK3172-SiP.