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….
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
Freescale has released a new Processor Expert Driver Suite: the version 10.3 🙂
Processor Expert Driver Suite 10.3 Splash Screen
Finally my Freescale TWR-K21F120M board arrived 🙂
TWR-K21F120M on the bench
For the next generation of INTRO Zumo robots I’m evaluating a new ‘brain’: more processing power, more FLASH, more RAM, more of everything 😉
In Part 1 of this series I have covered the SD card on the Arduino Ethernet shield. In Part 2 I’m hooking up the board to the network and will be able to ping it 🙂
Arduino Ethernet Shield with FRDM-KL25Z
Sometimes it takes a very long time to realize a project. Adding the Arduino Ethernet Shield R3 to one of my Freescale FRDM boards is one of it: it took me a year until I have found a few days to work on using the Ethernet Shield with my FRDM-KL25Z.
FRDM-KL25Z with Ethernet Shield
I have not everything in place yet, so I decided to publish things in parts. So this is about part one: using the Micro SD Card on the Shield.
Character based LCD displays are great: they are inexpensive, and it is rather simple to use them compared to graphical displays. Yes, they only can display text and custom symbols, but this is usually what I need. And pretty much all character displays are using the Hitachi HD44780 protocol, so it is a de-facto industry standard.
HD44780 compatible Dual Line Character Display
These displays have one big disadvantage: they need to be compatible with the original Hitachi interface and protocol. First display were mostly one line only, and had only few characters, typically up to 16. The protocol worked either with one or two lines on the display. Today’s display have usually two lines, with 16 characters. But what if I need more?
4-Line LCD (Source: Daniela Solorzano)
MCU on Eclipse 