https://devzone.nordicsemi.com/f/nordic-q-a/6024/softdevice-safe-twi-implementation-broke-with-sdk-8-0-0So I&#39;ve been using a user submitted SD safe TWI implementation that I found here. This has worked well so far, but upon updating to SDK 8.0.0 parts have broken. Now when I perform reads it continues to read past the correct number of bytes for long perioden-USTelligent Community 13Fri, 13 Mar 2015 00:20:58 GMThttps://devzone.nordicsemi.com/thread/21059?ContentTypeID=1Fri, 13 Mar 2015 00:20:58 GMT137ad170-7792-4731-bb38-c0d22fbe4515:7a8afd7e-1a46-456a-ab2a-410a66c7109eSeth<p>This one was dumb, but my application was expecting SD 8, but I still had SD 7 in memory and because the TWI implementation I was using was calling SD functions, unexpected behavior resulted. Now to solve my other various SDK upgrade related issues...</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/21058?ContentTypeID=1Fri, 13 Mar 2015 00:19:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:33769de1-5a6f-4b7b-9575-92e9ef021b32Seth<p>This is a good point about checking success. I can;t give you a great answer for why the provided library code doesn&#39;t work, but it has something to do with the SD using the PPI channels, and it does not work with the soft device initialized. I did solve my issue, about to post the answer below.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/21057?ContentTypeID=1Fri, 13 Mar 2015 00:01:00 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a3d571a9-c04c-473f-9728-4c1289645cbeRK<p>In what way is the standard twi_hw_master.c not softdevice safe, what happens when you just use that code as-is with a softdevice?</p> <p>As far as I can see from diff-ing that code it just replaces all the NRF_PPI-&gt;CH[0] calls with sd_ppi_* ones which do exactly the same thing, I&#39;ve not found a place it differs yet. It is true that when the SD is enabled one is encouraged to use the sd_* calls to ensure you&#39;re accessing available resources, but in this case you are, PPI channel 0 is reserved for the application, so the two should be identical (one without the SD overhead).</p> <p>The only other comment I can make about that code is it calls the sd_ functions but doesn&#39;t check their return values, again they ought to return success, but checking them would be good, even just in debug mode.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/21056?ContentTypeID=1Thu, 12 Mar 2015 21:03:51 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e7f07df4-f3e4-4dc6-9445-7ad523230598Matt Barr<p>Ouch, that&#39;s the TWI version I am using as well. Are you also using S110 8.0.0 and IC rev 3?</p><div style="clear:both;"></div>