I am testing WIFI signal strength with external antenna on WiPy 3 with latest FW (1.18.1.r1). I am using this antenna: https://pycom.io/product/external-wifi-antenna/

I scan for networks with this code:

from network import WLAN
wlan = WLAN(mode=WLAN.STA)
wlan.antenna(WLAN.EXT_ANT)
nets = wlan.scan()
for net in nets:
print(net)

I usually see rssi-values in the range -65 - -70, the same when I use the internal antenna. When I put my thumb over the integrated antenna rssi goes to appr. -85. This makes me belive that this antenna is in use.

Adding this code makes the board behave as expected.

from machine import Pin
p_out = Pin('P12', mode=Pin.OUT)
p_out.value(1)