https://devzone.nordicsemi.com/f/nordic-q-a/25605/nrf51-custom-board---keil-works-but-makefile-does-notHello, I have an NRF51822 custom board. I am trying to flash the code under C:\Users\Home\Desktop\nrf51\nRF5_SDK_12.3.0_d7731ad\examples\ble_peripheral\ble_app_uart\pca10028\s130 I am trying to flash it with KEIL and it works. I can see NORDIC_UARTen-USTelligent Community 13Tue, 17 Oct 2017 23:03:47 GMThttps://devzone.nordicsemi.com/thread/100929?ContentTypeID=1Tue, 17 Oct 2017 23:03:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:53bde85b-9d52-4a0e-9f7b-ba6198b3598cJai<p>You mentioned that you are using the &#39;default&#39; Makefile from the project folder. In my experience, when my coworkers develop the project in Kiel, and when I bring the same project over to my GCC environment, I have to update all the component folder paths and C file paths before I can run anything. Kiel does not update the Makefile automatically.</p> <p>So you probably just need to include the missing headers?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/100928?ContentTypeID=1Mon, 02 Oct 2017 09:24:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:294c350b-ebc4-4440-ac5e-a5fe1f4e5cf9Sigurd<p>Hi,</p> <p>Did you change the last line in the makefile, from <code>nrfjprog --eraseall -f nrf52</code> to <code>nrfjprog --eraseall -f nrf51</code> ?</p> <p>How much RAM and Flash do you have on the NRF51822 for the custom board?</p><div style="clear:both;"></div>