https://devzone.nordicsemi.com/f/nordic-q-a/122059/nrf21540-not-functioning-with-nrf54l15Hi, We are developing the module based on nRF54L15 with nRF21540.nRF54L15 working fine now nRF21540 not functioning. We have also verify with to connect nRF54L15 DK with nRF21540 EK board. We have checked the RSSI by to connect with nRF21540. pleaseen-USTelligent Community 13Thu, 05 Jun 2025 13:52:14 GMThttps://devzone.nordicsemi.com/thread/538245?ContentTypeID=1Thu, 05 Jun 2025 13:52:14 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ed21adf5-9722-444b-acab-a69c615633f8Bendik Heiskel<p>Hi Irfan,</p> <p>Can you define not functioning?</p> <p>Are you seeing low output power or no transmission at all?</p> <p>Using RSSI is not a good way to trouble shoot, as it is not a accurate measurement. For troubleshooting you need to be able to do real measurements of the output power using a spectrum analyzer.</p> <p>&nbsp;</p> <p>All BLE samples have by default a output power of 0dBm, even when built with a nRF21540, To change this you need to either set the output power statically using <code><span>CONFIG_BT_CTLR_TX_PWR_ANTEN</span></code> or dynamically using the ble hci commands, see the hci_pwr_ctrl sample:<br /><a href="https://github.com/nrfconnect/sdk-zephyr/blob/d07064e0c1c9f6b8f5c52d1ae9280b2b13894c99/samples/bluetooth/hci_pwr_ctrl/src/main.c#L82C1-L112C2">https://github.com/nrfconnect/sdk-zephyr/blob/d07064e0c1c9f6b8f5c52d1ae9280b2b13894c99/samples/bluetooth/hci_pwr_ctrl/src/main.c#L82C1-L112C2</a></p> <p>&nbsp;</p> <p>Best regards,</p> <p>Bendik</p><div style="clear:both;"></div>