“Note to myself: post articles about what students have done this semester…”
Students have turned in their semester project work. I have set for myself a goal to briefly describe to the ‘outside’ world what they did, as an inspirational source :-). So here is a first article about the project completed by Christoph Bühlmann who developed a shield for the FRDM-KL25Z board: a programmable ultrasonic shield:
Ultrasonic Shield with Freescale FRDM-KL25Z (Source: Christoph Bühlmann)
Question: How to build a low-cost logic open source logic analyzer for less than $15?
Answer: combine the Freedom KL25Z board with OLS!
500 Hz signal with 50% duty cycle in LogicSniffer
So I have now a portable GPS data logger (see “Tutorial: Freedom Board with Adafruit Ultimate GPS Data Logger Shield“). What to do with it? It would be cool to see the data and tracks in Google Earth? Yes, that’s doable in a few steps…
GPS Logger Waypoint Data with Google Earth Street View: Riding through Schwyz towards the Mythen Mountain peaks
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
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
MCU on Eclipse 