https://devzone.nordicsemi.com/f/nordic-q-a/46892/nrf52840-i2c-bus-lockHi, I&#39;m using nrf52840 TWI master. Sometimes the I2C bus result as locked in endless loop to retry the start conditions. I see that in this case SDA and SCL are tied low for some time (about 100msec) I am aware that these are very sketchy informationsen-USTelligent Community 13Fri, 03 May 2019 09:20:56 GMThttps://devzone.nordicsemi.com/thread/185111?ContentTypeID=1Fri, 03 May 2019 09:20:56 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d1c69fa6-70fb-4b78-b5dc-02d85f9868e5awneil<p>First thing to work out is if it&#39;s the nRF that&#39;s &quot;locking&quot; the bus, or (one of) the attached slave(s)</p> <p>This application note gives some suggestions on recovering a locked I2C bus:</p> <p><a href="https://www.analog.com/media/en/technical-documentation/application-notes/54305147357414AN686_0.pdf">https://www.analog.com/media/en/technical-documentation/application-notes/54305147357414AN686_0.pdf</a></p><div style="clear:both;"></div>