I have 2 of the nRF51 Dev. kits and have been ble to run Blinky, BLE_UART and set up the 2 dev kits so that I can send data from one DK to the other and to an external board on each that accepts the uart data and sends/receives to a terminal program. I have no problems building the projects and loading with nRFGo Studio. I am now trying to learn more about the actual software. I previously used TI's MSP430 MCUs. With the SDK there are many header files to look through and I am confused about where the port pins are set/cleared for input or output. I can see pins are assigned in the PCA10028.h file. I have not used ARM before. I just ish to set up simple programs where I can gradually build my program to do more complex tasks. I now have a PCB with a separate MCU to send/receive data via it's uart to the nrf51822 module. I wish to eliminate my MCU and use the module to do some basic functions. Can anyone suggest a place to start? I have been told that the support from Nordic is excellent which is one reason I picked their BT module. My knowledge of C is also a little rusty as I have been using assembler for some time. Any help would be appreciated.