https://devzone.nordicsemi.com/f/nordic-q-a/8706/not-able-to-set-transmission-power-using-s110-apisHi , I tried to change the transmission power using the s110 API and tried checking if the value of the register storing the transmission power is changed or not. Following is the portion of code code that I wrote: #define TX_POWER_LEVEL (-8) . en-USTelligent Community 13Fri, 14 Aug 2015 10:58:01 GMThttps://devzone.nordicsemi.com/thread/31929?ContentTypeID=1Fri, 14 Aug 2015 10:58:01 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9383ad06-a6c7-4339-abe2-50b6dbc721a5Ulrich Myhre<p>Yes, depending on how strict the memory protection is enabled to be (by default it is off) you will either get invalid values (often 0 or 255) or a HardFault.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/31928?ContentTypeID=1Fri, 14 Aug 2015 10:54:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:963067fa-bb2d-4406-ad1e-334e4d655534akhil<p>@Ulrich Myhre ok. yeah. You mean to say the protected peripherals can be read as document in the link you provided says, but will yield invalid values after being read. Am I right? Please correct me if I am wrong.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/31927?ContentTypeID=1Thu, 13 Aug 2015 10:32:04 GMT137ad170-7792-4731-bb38-c0d22fbe4515:255f65d9-24e0-4727-8195-67de5df5a2eeUlrich Myhre<p>Hi,</p> <p>When the SoftDevice is enabled, the RADIO peripheral is protected. Trying to access its registers while it is running will yield invalid values. For more information about the protected peripherals, refer to the individual SoftDevice Specification. <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.pdf.sds/S110_SDS_v2.0.pdf">Here is the one for S110</a>.</p> <p>There is currently no way to retrieve the TX power through an API call, but the SoftDevice will not change this by itself (unless you disable and re-enable the SoftDevice), so the last value given to sd_ble_gap_tx_power_set() should stay valid.</p><div style="clear:both;"></div>