Can mbed hex app run on custom board?

[gdou]

Hi, I have done the following:

1. Built a custom board with a brand new 128Kb nRF51822. On the board I only have the 16MHz xtal.
2. Routed out SWD IO/CLK and connected to an nRF51 DK external debug-out P20, with VDD/VSS connection as well.
3. I created a blinky_led HEX file from mBED to blink IO pin19 of the chip.
4. I used nRFgo or nrfjprog to load the HEX file, since external debugging of nrf51-dk does not support mbed. It goes through saying "programming successful".

However the LED connected on pin11 does not blink. I tried to load the softdevice first and then load the mbed HEX, but it says mbed HEX has info in the softdevice region and they conflict. I have two questions:

1. Does the fact that the burning process goes through fine mean that the custom PCB is built correctly? I was able to write, read, and erase the memory space. I'd assume if the PCB is faulty I won't be able to program the chip at all?
2. How do I get the pin11 to work? any hint? Does the HEX generated from mbed work on generic PCB with nrf51822?

Thanks!

###########Edit########### I have uploaded the mbed hex file - it's just a turn-on pin11, without any BLE stuff. I have tried the blinky from SDK using GCC and it works. Could it be because of the 128kb version that I need extra settings in mbed when compiling the HEX?blinky.hex

[Anders Strand]

Hello.

The hex generated from mbed should work.

Does your blinky project include any BLE libraries, or is it a pure blinky? Since you do not have a 32Khz crystal, a softdevice might not work because it uses an external 32kHz crystal by default.

The softdevice is places in the bottom of flash (address 0x00). The softdevice region error you get, is given because the blinky app is also compiled to be at address 0x00. Can you try the blinky example from our SDK, and see if that works? By doing this, we can eliminate the custom hardware.

1. Yes, but it does not mean that the application will run without errors.
2. It should work.

Can you send a link to the mbed project, or attach the hex file?

-Anders

[gdou]

I have added the HEX file in the original post. Thanks for the help!

[Anders Strand]

I flashed your hex to a nRF51 DK. Pin 11 is high. If you are making a "blinky", you should turn it off AND on, then it is easier to see if anything happens. Many LED's will turn on when the output is LOW. Maybe this is why your led is not lighting up?

[gdou]

Thanks Anders - Yes it will work on a nRF51 DK, but it does not work on the custom board. I made it pin11 high instead of blinky just to make it simple - and HIGH should light the LED in my board. I am wondering if the mbed compiles the HEX with a setting that does not work with my nRF51822 version, which is NRF51822-QFAB-R7. Is that possible?

[Anders Strand]

It is possible that the mBed code requires an external 32 Khz crystal. That is why i asked you if you had any BLE libraries in your project. Can you either send a link to the project, or export the project to Keil, and then upload it here?