https://devzone.nordicsemi.com/f/nordic-q-a/21144/twi-without-softdeviceHi, I just switch to Embbeded Studio following the last tutorial ( here ). I&#39;m working on NRF51822 with SDK12 and TWI_sensor example (without SoftDevice). I followed the tutorial to import Keil project.I can compile my project without problem. en-USTelligent Community 13Thu, 06 Apr 2017 13:27:04 GMThttps://devzone.nordicsemi.com/thread/82737?ContentTypeID=1Thu, 06 Apr 2017 13:27:04 GMT137ad170-7792-4731-bb38-c0d22fbe4515:268a590e-1f4c-47f8-ad2e-0c01412af640julienh<p>Thank you for your help. I don&#39;t know why but the value of err_code which is displayed in debugger mode is not the good one... I still have 0x01, I can&#39;t explain why. I added NRF_LOG to TWI module to debug and I can confirm that there is no error...</p> <p>Just have no ACK from the device but I should find the problem quickly.</p> <p>Thank you</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/82736?ContentTypeID=1Thu, 06 Apr 2017 07:49:15 GMT137ad170-7792-4731-bb38-c0d22fbe4515:2d2b119f-676a-4b4d-8874-050b5579addbbjorn-spockeli<p>The nrf_drv_twi is not dependent on the SoftDevice and consequently does not perform any SV calls. As @danify (Daniel Wang) says, nrf_drv_twi_tx() does not return that error code, see the API documentation <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v12.2.0/group__nrf__drv__twi.html#ga2c5ea8408254dfa9cbff55dbee171a95">here</a>. Please provide the returned error code in hex.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/82735?ContentTypeID=1Wed, 05 Apr 2017 20:13:19 GMT137ad170-7792-4731-bb38-c0d22fbe4515:56aa0e8c-4466-40b3-8a04-8f547f687868Daniel Wang<p>Are you sure that it&#39;s <code>NRF_ERROR_SVC_HANDLER_MISSING</code>? I don&#39;t think it should be possible that <code>nrf_drv_twi_tx()</code> function return that err_code. What number is the err_code ?</p><div style="clear:both;"></div>