I'm trying to program a nRF51822 custom board using Debug out pin P19 of NRF51-DK through Keil MDK, here is the problem I encounter:
To simplify I just use the simple blinky_s130_pca10028 project. First I compile and load the program to DK on board 51422 chip without problem. The LEDs were blinking.
Then I connected the custom board to NRF51-DK via Debug out P19 using a 10pin cable, but just use 4 wires which are EXT_VTG, EXT_SWIO, EXT_SWCLK, and GND.
Then I powered up the custom board with 3V voltage.
After that I clicked Load button in Keil, erase and program successfully! The strange thing is all the messages was the same like I programmed the on board 51422 chip (Target info:-Device: nRF51422_xxAC, VTarget = 3.300V), but I know it wasn't really loaded to the on board chip because the LEDs were keeping blinking during the flashing process. And if I disconnect the EXT_SWCLK wire from the custom board and Load again it shown a error message: No Cortex-M SW Device Found. Which means the DK is able to detect the custom board.
So I suppose the program was loaded to the external custom board. Unfortunate there was no signal output from the 51822 chip of the custom board , which means the program may not correctly loaded to the external 51822 chip. I verified all the connections and voltage, it's all good.
So I don't know if I missed something? If 51-DK programs the custom board, should the target info the same like I program the on board chip (such as Target info:Device and VTarget etc. ) ? I know the VTarget = 3.3V was not correct because the target board voltage should be 3V instead of 3.3V, and what the Device name it should show?
Many thanks for the help! I have been stuck here for couple of days!
