https://devzone.nordicsemi.com/f/nordic-q-a/47759/ble-eddystone-example-unable-to-change-tlm-tx-powerGood day, I program my nRF52-DK with BLE Eddystone example&#39;s pre-compiled hex: \nRF5_SDK_15.3.0_59ac345\examples\ble_peripheral\ble_app_eddystone\hex\ble_app_eddystone_pca10040_s132.hex Slot 0 transmits URL frame by default at 0dBm. I then use nRFen-USTelligent Community 13Tue, 28 May 2019 08:01:35 GMThttps://devzone.nordicsemi.com/thread/189487?ContentTypeID=1Tue, 28 May 2019 08:01:35 GMT137ad170-7792-4731-bb38-c0d22fbe4515:04d43e59-77f8-4c22-bdfe-791e0f812033NordicHam<p>Noted, thank you&nbsp;Torbj&oslash;rn.</p> <p></p> <p>Regards<br />Jacques</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/189478?ContentTypeID=1Tue, 28 May 2019 07:45:14 GMT137ad170-7792-4731-bb38-c0d22fbe4515:45218c3f-5661-499a-976f-8cc65cc6e188ovrebekk<p>Hi</p> <p>I reproduced the problem, and traced it down to an app_error_check on line 154 of es_slot.c in the Eddystone source code.&nbsp;</p> <p>Essentially the nRF52 will assert if you try to change the TX power on a TLM slot, it will only work on UID, URL and EID slots.&nbsp;&nbsp;</p> <p>One of the designers believe this is enforced by the Eddystone specification, and that you are not supposed to set TX power directly on TLM&nbsp;packets.&nbsp;</p> <p>As mentioned <a href="https://developers.google.com/beacons/eddystone">here</a> &quot;<span>TLM should be interleaved with an identifying frame such as Eddystone-UID or Eddystone-EID&quot;, and you can set the TX power on the interleaved UID or EID packet (slot) instead.&nbsp;</span></p> <p><span>So for now please refrain from trying to set the TX power on a TLM slot. I will discuss this with the app developer and see if we should change the app to remove this configuration field for TLM slots.&nbsp;</span></p> <p><span>Best regards<br />Torbjørn</span></p><div style="clear:both;"></div>