https://devzone.nordicsemi.com/f/nordic-q-a/20210/p0-09-as-gpioHello I try to use P0.09 as GPIO with this simple code but not working. (Works well with pin P0.08) #include &lt;stdbool.h&gt; #include &lt;stdint.h&gt; #include &quot;nrf_delay.h&quot; #include &quot;boards.h&quot; const uint32_t UICR_ADDR_0x20C __attribute__((at(0x1000120Cen-USTelligent Community 13Tue, 03 Apr 2018 07:36:02 GMThttps://devzone.nordicsemi.com/thread/126587?ContentTypeID=1Tue, 03 Apr 2018 07:36:02 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0921f00b-f399-43ec-87fd-972f6dc9acbfFormerMember<p>I will add it as a suggestion internally.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/126429?ContentTypeID=1Fri, 30 Mar 2018 05:53:03 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ed6a2db7-1926-4464-b86e-33a0f4ddc096Manoj Hiwarkar<p>why this cannot come with&nbsp;<span>development kit. Why consumer has to struggle.?</span></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/78746?ContentTypeID=1Mon, 06 Mar 2017 11:41:25 GMT137ad170-7792-4731-bb38-c0d22fbe4515:cfa9829b-7f92-48f3-a5ed-eeb6443914c4manymany<p>In fact the code is working but on the development kit PCA10040 board pin P0.09 is not connected resistor R27 and R28 must be added.</p> <p><img src="https://devzone.nordicsemi.com/cfs-file/__key/communityserver-discussions-components-files/4/NFC_5F00_R26_5F00_R27.jpg" alt="image description" /></p><div style="clear:both;"></div>