https://devzone.nordicsemi.com/f/nordic-q-a/4942/redbear-blendmicro-nrf8001---constant-tx-power-direct-test-modeHi, I am a new comer to the nRF8001. I am using Redbear Blendmicro (nRF8001) for my project. I have wrote a apps to scan my Blendmicro(s) and acquire their RSSI value so that the distance between BLE and smartphone could be deduced. Howeveren-USTelligent Community 13Mon, 29 Dec 2014 09:31:56 GMThttps://devzone.nordicsemi.com/thread/17430?ContentTypeID=1Mon, 29 Dec 2014 09:31:56 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ec6ca679-7ae0-4de5-a473-a2b4ae08877enamed.kai<p>Hi Star,</p> <p>Thanks for the reply. I will try to modify the code at later on.</p> <p>Besides, as mentioned, the influence may be caused by reflections and multi-path, do you think the fluctuating RSSI value may due to Doppler effect also? If yes, the estimated distance is valid only if the transmitter (Say, Blend micro) is static !!</p> <p>Regards, Angus</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/17429?ContentTypeID=1Sat, 27 Dec 2014 22:31:36 GMT137ad170-7792-4731-bb38-c0d22fbe4515:dd168337-df57-4942-8f82-34890351b305David Edwin<p>The default TX power is 0 dBm. The test mode that you mention is typically used for RF compliance tests. Look at the ACI Test command in section 24 of the nRF8001 datasheet.</p> <p>It is also likely that your RSSI is changing due to the antenna design used, on the blend micro and the smartphone, additionally reflections and multi path influence RSSI, so even if the transmit power is the same the RSSI can change.</p><div style="clear:both;"></div>