For the first generation of the INTRO Zumo robots, I have Pololu optical wheel encoders (see “Adding Quadrature Encoder to the Zumo Chassis“) which were available last year. It seems that Pololu heard my feedback, and are offering new encoders. Time to move things to the next level, using an optical encoder attached to the motor shaft:
Optical Motor Shaft Encoder
As mentioned in Part 9: There is a new GNU ARM Eclipse plugin 2.1.1, and this one makes project creation for Freescale devices easier than ever 🙂
GNU ARM Eclipse 2.1.1
On Monday the new semester starts, and yet again: we will do a Sumo thing :-). They can choose which tool chain they would like to use to develop their application for the ARM Cortex-M0+ used from Freescale. One option is to create a ‘Do-It-Yourself’ toolchain. Since the start of the series, things have evolved: there is a new GNU ARM tool chain available, Segger has updated their drivers, and most important the GNU ARM Eclipse plugin has been greatly extended to support Freescale parts and Processor Expert. So instead to read through all the previous tutorials, this one is about putting together a free tool chain less than 10 minutes (not counting the time to download around 500 MByte).
DIY Eclipse Toolchain
University research projects can be a lot fun, and are very challenging the same time. The good thing is that there is always someting new to learn :-).
This week-end I was working on my Internet of Things (IoT) project, based on a Freescale KL15Z and a nRF24L01+ transceiver. In essence it is a wireless data logger. For this, I only can afford a few micro amps consumed by the whole board over an extended period of time. I mean 21 micro amps for running a whole board with sensor, EEPROM, wireless transceiver, operating system and an ARM Cortex-M0+ ready to crunch numbers at 20 MHz 🙂
21 micro amps for wireless sensor node (when not sending)
I have carefully implemented my firmware. It works perfectly for hours, days, months, maybe for years. If there would not be this problem: the firmware crashes sporadically :-(. Yes, I’m using watchdogs to recover, but hey: it is a serious problem. And because it happens only under rare and special conditions, it is hard to track it down or to debug it.
Accessing shared data from the main application and from an interrupt
The thing is: these nightmares exist, and they are real and nasty. I’m pushing my students hard on this topic: It is about how to protect critical sections. And what could go wrong. And here is just yet another example: how it can go badly wrong if you are not careful. And it took me a while too to realize where the problem is. It was not a fun ride….
There has been many new releases these days: Freescale released Processor Expert Driver Suite 10.3, and Liviu Ionescu released new GNU ARM Eclipse Plugins with new and updated documentation. So time for me to show how this all comes together 🙂
Processor Expert Driver Suite 10.3 Project with GNU ARM Eclipse Build Tools
It is now easier than ever before to use the GNU ARM Eclipse plugins and Processor Expert. There are still some manual steps, and this post is about all the details to get it working as smooth as possible.
The Freescale Tower boards are very versatile, and there are many different boards you can combine like lego bricks. When I tinker with my own hardware or need to try out something, then I use a special prototype board: the TWR-PROTO.
Tower Proto Board Frontside
I’m maintaining and hosting now more than 100 different Processor Expert components on GitHub. Instead to deal with CDE (Component Development Environment, that’s the SDK to create your own components), most users simply download and install the PEupd files. If you deal with normal source files, and if spot something you want (or need to change), then you can easily do this. But what if you want or need to change something in that code which comes with the PEupd file(s)?
Components in the Components Library
I have I project which I want to debug on multiple boards the same time. So how can I download and debug the same application to multiple boards/processors, and debug them all the same time from within the same workspace and Eclipse IDE?
This is a typical scenario I have with my RNet stack: the same application runs on multiple boards, and I want to debug all the boards with the same project with the same Eclipse. For example to wireless sensor nodes with the RNet nRF24L01+ stack as in the picture below:
Two FRDM-KL25Z with nRF24L01+ Transceivers
Tired by the tool chains provided by your silicon vendor? Do you want to use a free and open tool chain? Then you probably followed by “DIY Free Toolchain” series already. In “DIY Free Toolchain for Kinetis: Part 2 – Eclipse IDE” I used the standard GNU Eclipse plugins. As mentioned in above post, there is an even better and more powerful plugin available: the GNU ARM Eclipse plug-ins. There is a dedicated blog site which provides excellent documentation and direct access to new and frequent releases. And these days there is a true a Christmas gift for every Eclipse lover: the version 1.1.7 with the addition of J-Link debugger plugin :-).
GNU ARM Eclipse
MCU on Eclipse 