One of my embedded projects is to measure the running time in a sports event (see “Sports Timing System in a Lunch Box“). The recorded time is stored in an EEPROM plus sent over USB or wireless connection to the host. It would be great if I could print out the time and ranking directly, so if there is no PC, the system can be small and tiny. So here is my next project and tutorial: Printing with the Freedom board!
Hello World on the Printer with FRDM-KL25Z
Using Processor Expert is an awesome tool: it generates source code for me, and I can can ‘dynamically’ tune my projects to my needs. Still, sometimes it is better or desirable to have a ‘normal’ or ‘static’ project. This is very well possible with Processor Expert (see “Sneaking from Processor Expert” or “Disable my Code Generation“): I can generate the code one time, and then use it without Processor Expert.
To make this even easier, I have added an option to the FreeRTOS Processor Expert component to generate ‘static’ code I can copy-paste to projects and tool chains which are either not supported by Processor Expert, or just for ‘static’ projects.
FreeRTOS Custom Port Settings
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
Naturally, I have several project ideas lingering around. No time to make them all (for now). One of it is interfacing the Raspberry Pi camera with a microcontroller. To store the images, I need plenty of RAM on the device, and so far the Kinetis microcontroller did not have that. Finally, Freescale announced the K64F120 a few months back, and my ordered TWR-K64F120M board arrived on my desk, waiting to be used: Finally I get an ARM Cortex-M4F with 1 MByte of FLASH and 256 KByte of RAM :-).
TWR-K64F120M Box
The final FreeRTOS V8.0.0 has been released last week: time to update the Processor Expert component for it, and this time it is really a major release 🙂 : from V7.5.0 to V8.0.0:
FreeRTOS V8.0.0 Processor Expert Component
FreeRTOS V8.0.0 comes with many small changes, especially it now includes many of the extra casts I have contributed to avoid compiler warnings. And additionally it has a brand new feature: Event Groups.
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
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 created and published on GitHub a new component ‘CriticalSection’:
Critical Section Component Methods
This component is a wrapper between my components and the problematic current implementation in Processor Expert (see EnterCritical() and ExitCritical(): Why Things are Failing Badly). It uses a flexible approach and uses macros to either use my modified version of EnterCritical() and ExitCritical(), or simply defaults to the original implementation.
This is Part 3 of an ongoing tutorial to use the Arduino Ethernet Shield R3 with a Freescale FRDM-KL25Z board (or any other board you like).
In Part 1 I worked on the SD card, in Part 2 I have added basic network connection. Now time to run a web server with my FRDM-KL25Z :-). With this, I can get access to my board through the network, and the board will host a web page where I can do pretty much everything: showing status, or adding functions to turn on things like an LED 🙂
Web Server with W5100 on FRDM-KL25Z
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.
MCU on Eclipse 