https://devzone.nordicsemi.com/f/nordic-q-a/9436/iot-sdk-connect-twi-i2c[Dev Env] nRF51 DK IoT SDK 0.8 IoT SoftDevice [Question] anybody help me. In Iot SDK can&#39;t access TWI interface? any Sample ?? HardFault_Handler (/attachment/fbd403f1c1c47dcb2a8365c80f82a589) bool twi_master_init(void) { . en-USTelligent Community 13Fri, 25 Sep 2015 13:19:44 GMThttps://devzone.nordicsemi.com/thread/34831?ContentTypeID=1Fri, 25 Sep 2015 13:19:44 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e3a18f2a-e53d-4c3c-af97-ec32d311ff24RK<p>PPI is a restricted peripheral, and in earlier versions of the softdevice, that causes direct access to it to cause a hardfault. There are sd_ functions to access the PPI channels safely, you should use those.</p> <p>However .... that hack for using a PPI channel to stop the TWI device was only ever needed for the 1st version chips with the anomaly that the TWI shortcut didn&#39;t work, that was fixed in version 2 of the chips, a long, long time ago and there&#39;s no need to use a PPI channel at all any more. You can change it to use the now-working shortcut - or switch to the more-recent nrf_drv_twi.c if you have recent-enough hardware to run it on.</p><div style="clear:both;"></div>