https://devzone.nordicsemi.com/f/nordic-q-a/5104/the-new-dk-vs-the-old-ekWhy is the &quot;old&quot; EK &quot;not recommended for new designs&quot;? Will the old EK work with the IOT SDK? (Maybe it is chip rev dependent? I don&#39;t have the my EK on hand so I don&#39;t recall what rev 822 is on it, I got it in April 2014 when the newer revs came outen-USTelligent Community 13Tue, 13 Jan 2015 15:51:18 GMThttps://devzone.nordicsemi.com/thread/17951?ContentTypeID=1Tue, 13 Jan 2015 15:51:18 GMT137ad170-7792-4731-bb38-c0d22fbe4515:33b81e2c-3c61-4561-8a26-5a5c1fcb6e84Stefan Birnir Sverrisson<p>Hi Simon</p> <p>As a rule of thumb, a new design should use the latest hardware revision as it has some fixed anomalies and has somewhat better performance, see <a href="https://www.nordicsemi.com/eng/nordic/Products/nRF51822/PCN-092/38893">PCN-092</a>. I expect that your EK should work with IoT SDK, as long as you have second or third nRF51 hardware revision residing on your EK. Just follow the guide <a href="http://developer.nordicsemi.com/nRF51_SDK/doc/7.1.0/s110/html/a00018.html">here</a> to have the leds and buttons mapped correctly on your EK.</p> <p>You should be able to see what hardware revision you have by looking at the chip markings on the nRF51 chip on your EK and compare them with the build codes given in the <a href="https://www.nordicsemi.com/eng/nordic/Products/nRF51822/ATTN-51/41917">nRF51 compatibility matrix</a>.</p><div style="clear:both;"></div>