Many applications need to store persistent (non-volatile) data at runtime: configuration data, error logs, sensor data, calibration values, etc. The question is: where to store that data? If it is only a few kBytes, an SD card or similar is an overkill. Adding an external EEPROM? Sure, that works, but adds an extra part to the design. Some microcontroller have internal EEPROM. But what if not? Why not using the microprocessor internal flash memory?
Internal FLASH vs. external EEPROM
Many times I start with a project and tutorial, only to get interrupted for emergency tasks and assignments. For a long time I wanted to add GPS (Global Positioning System) functionality to one of my projects. While I started a few months ago on this, it took me until this week-end to finish the at least the first part: a SD card data logger with GPS :-): I calculate global positioning and time information, can use it in Google maps and store it on a SD card:
Adafruit GPS Data Logger Shield on a FRDM-KL25Z Board
With the Joystick shield I have a convenient way to drive and control a Zumo Robot without a wired connection:
Joystick Shield with Robot
While things started promising, there was a power supply problem at the end to be solved…
The latest addition to my set of Arduino shields is a true fun thing: The ElecFreaks.com JoyStick Shield 🙂
ElecFreaks.com Joystick Board with FRDM-KL25Z and nRF24L01+
I admit: my Ethernet Shield project got stuck because of too many urgent other priorities. I was not happy with the way the project was using configuration data from FLASH memory: I have now multiple ethernet shields in use, and configuring the IP address for each shield is a pain. I have not got DHCP working (yet), so why not using the SD card on the shield for configuration data? And right on time I received a tip from Marc about MinIni: perfect, exactly what I need!
Ethernet Shield with SD card
I should have known it better, and I always teach my students that they should take the environment into account. And you know what? This time it was me who missed following that rule.
But from the beginning: For the Freescale Technology Forum (FTF) I brought 4 different Zumo Robots to show developing with the Freedom board and Processor Expert. Clark (thanks again, Clark!) has built and brought the Sumo Dojo, and I brought the bots:
Four Zumo Bots at FTF
I’m attending the Freescale Technology Forum (FTF) in Dallas this year: As they say here: “everything is bigger in Texas”, that’s the motto of this conference ;-). The conference is packed, and I have a hard time to keep up with all the things going on. My focus is obviously everything around Eclipse and ARM microcontroller. The conference started yesterday afternoon with hands-on labs, and I was in the one were Freescale presented the new ‘Kinetis Design Studio’: a free of charge/unlimited Eclipse tool chain based on Eclipse Kepler, GCC and GDB. Freescale presented their new software library ‘Kinetis SDK’. And: There is a new Freedom board which gets handed out to the attendees: the FRDM-K64F :-).
Texas Style Glass Coverage
Freescale opened its doors for students in Bucharest on March 28th. At the event there were more than 80 students and professors from Bucharest and across Romania with participation of the universities from Cluj, Constanta, Craiova, Iasi and Pitesti.
Two Sumo Bots
The great thing with Processor Expert is: it writes the code for me :-). I’m using now the RNet wireless stack in more than 10 different projects, and keeping the projects up-to-date with the RNet stack sources in a traditional way gets harder and harder: I need to make sure the paths are pointing to the right place, and if I pass the project to somebody else, I have to make sure all the sources are packaged with that project. Processor Expert makes things simpler: it can generate the source files into my project, and I can easily configure it.
So instead to copy and support files by hand, I decided to package the RNet stack files into a Processor Expert component: all still normal C files, but easier to configure and distribute.
RNet Component
In “IoT: FreeRTOS Down to the Micro Amps” I’m using an application with FreeRTOS to get down in micro amps low power mode. Well, nearly all or my applications are using FreeRTOS because it makes the application scalable and extensible. Still, for anyone not used to an RTOS, that might be a hard start. So here we go: how to get into the Kinetis Low Power LLS Mode *without* an RTOS.
Power Measurement
MCU on Eclipse 