Monday, December 09, 2013

Setting up Eclipse under Mac OS X for the Nordic Semiconductor nRF51822

I'm developing a smartwatch with the Nordic Semiconductor nRF51822 IC (a really nice chip!).

The development environment that comes with Nordic's Development Kit is based on Keil (a very expensive commercial IDE), which has a limit of 16K code to use in circuit debugging. Therefore I want to set up a development environment on my Mac using free and open source tools. Nordic has an application note, nAN-29, which describes doing this for Windows.

I will try installing the GCC ARM Embedded, because according to this post on the Nordic forums (quote):

  1. a new gcc toolchain based on gcc ARM embedded instead of Codesourcery (As Nordic has chosen to support it and not the other)
  2. Codesourcery on Mac OSX is only a great trouble, as this toolchain lacks of S3 Mentor libs) 
  3. Nordic has released new linker scripts for gcc ARM embedded.
I'm going to try to use Eclipse rather than XCode, so that the project won't depend on OS X.

I downloaded the "Mac Installation Tarball", which didn't contain an installer. I'm not sure where to put it, so for now I'll put it in my Eclipse workspaces folder.

I created a symbolic link (not an alias) called "gcc-arm-none-eabi" so I wouldn't have to change paths in the project if I update the cross compiler version.

I installed Eclipse according to nAN-29. When I build, it tries and fails to use "C:/Program Files/GNU Tools ARM Embedded/4.7 2013q1/bin/arm-none-eabi-gcc" to compile the project. I need to find where to change this path.  nrf51_sdk_v5_0_0_34603/nrf51822/Source/templates/gcc/Makefile.common uses a GNU_INSTALL_ROOT environment variable, I wonder where it is set.

The file nrf51_sdk_v5_0_0_34603/nrf51822/Source/templates/gcc/Makefile.common references Makefile.posix, which does not seem to exist.

GNU_INSTALL_ROOT is set in, but I don't see why is used. I'll try to make a Makefile.posix and see if it works better.

I made a Makefile.posix as follows:
GNU_INSTALL_ROOT := /Users/erlandlewin/Eclipse-workspaces/gcc-arm-none-eabiGNU_VERSION := 4.7.4
GNU_PREFIX := arm-none-eabi
 I had to edit the Makefile.common as follows:
#ifeq ($(OS),Windows_NT)
#include $(TEMPLATE_PATH)
include $(TEMPLATE_PATH)Makefile.posix
I can now build the project in Eclipse and from the command line!

I will download the J-Link software for Mac from here.

 Followed the instructions in nAN-29 to set up the debugging. In the "GDB command" field of the Debug Configurations dialog, I used the Browse button to find the arm-none-eabi-gdb binary. This way I don't have to set up any paths.

I start the gdb server using the terminal from the /Application/SEGGER directory, using the following command line:

./JLinkGDBServer -if SWD -device nRF51822
(Thanks to info from Christopher Mason)

Woohoo! I can now run debug the ble_app_hrs project from Eclipse via the JLinkGDBServer!