I admit: I love command line interfaces. Because that gives me usually much more control than any GUI (Graphical User Interface). I like the fact that they have put a UART interface on the RIoT board:
J18 UART on the RIoT Board
After the problems with level shifters (see “First Adafruit NeoPixel Blinks with the FRDM Board“) I received the ordered 74HCT245N. Put it on a bread board, wired it up, … only to find out that the device gets very hot… turned off power, and realized that had the device put in with a wrong orientation 😦 oh darn! That’s why I always order things like that in quantities of 3 or more :-). Corrected the mistake, and things are running (or blinking) again 🙂
74HCT245 Wiring for WS2812
I had great plans for this Saturday: to work on really cool project. But as so many times, things turned out to be different. Maybe you have read my recent posts about printf()? A colleague wanted to use that article to the same thing with the Kinetis Design Studio on the FRDM-K64F board. I used the FRDM-KL25Z board, so I expected this to work out of the box for him too. Well, turned out that I was wrong about this, and my Saturday was used for debugging and googling about a printf() problem 😦
While things work as expected for the FRDM-KL25Z (ARM Cortex-M0+) and using the standard GNU GCC ARM Embedded from the launchpad, the application traps on the K64F (ARM Cortex-M4F) in initialise_monitor_handles() with KDS:
Trap in initialize_monitor_handles()
The Freescale Kinetis Design Studio (KDS) V1.0.1 beta is using a different GNU ARM toolchain than the ARM Inc. supported one on launchpad (GCC ARM Embedded). Additionally, KDS is using newlib 1.19 and newlib-nano 1.0, while there just has been a new release of the GCC ARM Embedded a month ago with the 4.8.4 update 2 release in June this year. So how to upgrade KDS to the latest and greatest GCC ARM Embedded?
In “Semihosting with Kinetis Design Studio” I’m using the debugger with semihosting to output text with printf(). But how to use a physical serial connection instead?
printf() and scanf() in action
This post is about how to enable and use printf() and scanf() with GNU ARM libraries. I show it both for the Freescale Kinetis Design Studio (KDS) and for stock Eclipse Kepler with the GNU GCC ARM Embedded (launchpad) toolchain and libraries. The principles are the same, just the details are different ;-).
While new Freescale boards come with the OpenSDA debug firmware, I still students using boards with the OSBDM/OSJTAG. And with new CodeWarrior tools, it might be that there is a new OSBDM/OSJTAG firmware, and when I download to a board with an older firmware, the tool will prompt me to update the firmware. To me, after doing this several times, not a big deal. But for someone who sees this the first time, it might not be that easy. So to avoid any further questions, here we go with a step-by-step tutorial how to update the OSBDM/OSJTAG firmware.
MCF52259 Tower Board with OSBDM Firmware
So I have a graphics driver for a Nokia display (see “Zero Cost 84×48 Graphical LCD for the Freedom Board“), I have a joystick shield (see “JoyStick Shield with the FRDM Board“) and I do have a Freescale Freedom board: why not creating a simple game for it? Snake!
Snake Game with FRDM-KL25Z Board
For some time I’m using the Nordic Semiconductor nRF24L01+ transceiver successfully in many projects (see “Tutorial: Ultra Low Cost 2.4 GHz Wireless Transceiver with the FRDM Board“). Since that tutorial things evolved a lot with the introduced RNet Stack. To honor the popularity of the Nordic Semiconductor nRF24L01+, Freescale has put a socket on the FRDM-K64F board. So time to make a new step-by-step tutorial how to use the nRF24L01+ with the FRDM-K64F.
Two FRDM-K64F Boards with nRF24L01+ Transceiver
Andreas populated the first board with SMD parts and sent it through the reflow oven. The 32 kHz quartz is missing because not all parts arrived on time. The soldering of the Freescale Kinetis K22 microcontroller is not perfect yet, so will need some tweaking and inspection under the microscope, as well some other parts. Christian will do an inspection and electrical tests, then it will be my job to get it connected to the debugger. Keep my fingers crossed to get a blinking LED 🙂
First new Zumo Robot Board, out of the Reflow Oven
As you might have read it already: for the new semester we plan the next generation of Sumo Robots: still based on the Pololu Zumo Chassis, but instead using the FRDM board with the processor, we directly put a Kinetis K20 processor on the board :-).
Old (top) and new (bottom) PCB with solder mask
MCU on Eclipse 