https://devzone.nordicsemi.com/f/nordic-q-a/8914/what-is-the-difference-between-gpios-of-nrf51422-and-nrf51822Hii all, I wanted to generate a clock pulse from the pin P0.05, I&#39;ve written the code and when I tested the application with nrf51 DK with chip 51422-AC its working fine and I can able to see the clock, but when I changed the linker script to aa anden-USTelligent Community 13Thu, 27 Aug 2015 09:24:12 GMThttps://devzone.nordicsemi.com/thread/32805?ContentTypeID=1Thu, 27 Aug 2015 09:24:12 GMT137ad170-7792-4731-bb38-c0d22fbe4515:934b6ef4-4a0d-4954-a66a-bf2fa513a99eStian R&#248;ed Hafskjold<p>The chips are equal except for the RAM, which should be handled by the linker script. (And that 822 doesn&#39;t support ANT). Also, there are different chip revisions which is given by the xx in nRF51822xxAA. Check out the <a href="http://infocenter.nordicsemi.com/index.jsp?topic=/com.nordic.infocenter.nrf51.v1.0.0/pdflinks/nrf51_comp_matrix.html">compatibility matrix</a> to see which chip you have and which SDK and SD that goes with that chip.</p> <p>The GPIOs depends on the board you are using. Is it the PCA10001 board you are using for the xxAA chip? Try to define the right board in the makefile (i.e. BOARD_PCA10001) to get the right GPIO settings.</p><div style="clear:both;"></div>