Warning !
This repo is not maintained anymore, here is the new one:
https://github.com/medialablasalle/twiz
What?
TWI stands for Tangible Wireless IMU. It is basically composed with a 9 axis IMU and an ARM-BLE SOC made by Nordic Semi, the nRF51822. This repository contains the software to program this CPU, and the PCB can be found here:
How?
Base
Before testing on the custom PCB a cheap dev board can be used:
...this cheap programmer is fine too:
Once everything is gathered, most of the nRF51822 bringup procedure can be made thanks to this tuto:
http://www.funwithelectronics.com/?id=168
Workarounds
A few steps might no work when following this tutorial, here are a few solutions:
1) It might not be useful to download the Mentor toolchain, it is incomplete. Instead, the one Linaro one can be used (from the official ARM developers):
https://launchpad.net/gcc-arm-embedded
2) [This section is not useful anymore, Nordic opened access to all the useful files] If you miss the Nordic files you can use git to travel in the past:
https://github.com/Sproutling/nRF51822-OSX-Sample
It won't be the latest version but you should find what you need. The nrf51 SDK install doesn't always work with wine. A Windows XP in virtualbox doesn't alway help but it works with a real windows (vista for example).
3) The linker script used in the tuto's makefile is supposed to be given by
Nordic but it doesn't seem to exist anymore (with this name) so this one can be
used: gcc_nrf51_blank_xxaa.ld
4) You have to define your exact CPU such as NRF51422_QFAA_C0 in your CFLAGS
otherwise it won't compile compile (but you might be using another kind of CPU).
5) In Ubuntu, to be able to use the segger script, you might need to install
lib32readline5 even if you use a 64 bits OS.
6) Known issues:
a) If an error such as the following happens, you might need a 32bit verion of libusb:
./JLinkExe: error while loading shared libraries: libusb-0.1.so.4: cannot open shared object file: No such file or directory
This command might help finding the culprit:
apt-file search libusb-0.1.so.4
The following should solve the problem:
apt-get install libusb-0.1-4:i386
b) Similarly, if you get this error:
./JLinkExe: error while loading shared libraries: libjlinkarm.so.4: cannot open shared object file: No such file or directory
The following should solve the problem:
export LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH
In general ldd /opt/JLink/JLinkExe, should help finding which libraries are missing (adapt your path).
Bonus!
- Video of the 1st blinking test:
- Test IMU (video here):
Enjoy!
A lot of awesome nRF51 repo are available on github or bitbucket, but feel free to ask if you need any help:
contact(a)honnet.eu
May the force be with you!
License
This project is released under a Creative Commons, Attribution-NonCommercial-ShareAlike, Version 3.0 License: http://creativecommons.org/licenses/by-nc-sa/3.0