ESP32-S3-WROOM external antenna

[AcmeUK]

I have a ESP32-S3 UNO with a ESP32-S3-WROOM chip.

If I run a Bluetooth scanner I get the same RSSI with and without the external antenna connected.

Is the chip connected to an onboard antenna? If so how do I activate the external antenna?

[lichurbagan]

Most ESP32-S3-WROOM boards do have an onboard antenna. The ESP32 won’t automatically switch to your external antenna unless the board is designed for it. You may need to change the RF routing on the PCB.

[AcmeUK]

Hi Lichurbagan

My ESP32-S3 UNO board has a U.FI connector on the chip.

See image on this link https://en.paradisetronic.com/products/ ... kompatibel

Thus I assume a connection to an external antenna is available.

[AcmeUK]

Further research indicates that the external antenna is already selected automatically.

So, I am mystified as to why can I receive Bluetooth signals without an external antenna connected, but connecting an antenna makes no difference to the received signal levels?

[lbernstone]

Is that an Espressif branded module? AFAIK, the ESP32-S3-WROOM modules have either an IPEX or a PCB antenna, not both.

[AcmeUK]

I am confused; if I scan for Bluetooth devices and get the RSSI, I get the same RSSI with or without the external antenna connected.

If I scan for Wi-Fi devices and get the RSSI, I get at least 3dBm lower with the antenna connected e.g. -48dBm V -52dBm.

I have repeated these tests on a second ESP32-S3 UNO board with similar results.

HOWEVER, if I do the tests on a ESP32 Devkitc V4, ie with PCB antenna, I see a higher Bluetooth RSSI -63dBm V -81dBm

With the Wi-Fi scan the ESP32 Devkitc V4 I see a higher RSSI -45dBm V -52dBm.

So my conclusion, based on my adhoc tests, is that either the ESP32-S3 UNO board is a poor design, OR that the ESP32-S3 WROOM with the external antenna connector has issues.

I was not able to test a ESP32-S3 UNO without an external connector on the WROOM chip/module, as when I ordered one the vendor shipped one with the external connector. When I questioned why, they said that was all they now stocked!

My way forward will be to abandon the UNO board and use a Devkit type board WITHOUT an external antenna connector.

Any thoughts guys?