I mentioned in “Debug External Processors with USBDM and Freedom Board” post that I had a problem to debug the FRDM-KL05Z with USBDM. Well, after a long night with some sleep, with more thinking and searching, finally I have it resolved: I can debug my FRDM-KL05Z with USBDM 🙂
FRDM-KL05Z Debugging with USBDM
Teaching at a university means to work in a very special environment. What students love is ‘Open Source’: because it allows them to ‘see’ things and learn from the technology. The other thing is: students have a low budgets, so they appreciate if they can use inexpensive or low-cost hardware and software. The FRDM-KL25Z Freedom board for sure meets that low price, and no extra programming device needed.
Now they are building their own boards, and they wish to program and debug it. They can borrow the Segger J-Links and P&E Multilinks we have available at the university. But why not use the Freedom board as ‘hobby’ debug and programming solution? As explored in “Using the Freedom Board as SWD Programmer“, they can use the default factory installed OpenSDA to program another microcontroller of same type. But not to debug it.
While writing the “Using the Freedom Board as SWD Programmer” article, I was looking into USBDM. USBDM has added in January 2013 support for OpenSDA. But at that time, it was somehow not working for me, and I had not enough time to find out what the problem was. Time to get that fixed. Good news: With help and tips from the USBDM community, I have it finally working 🙂
USBDM Debugging another FRDM-KL25Z
I love the Freescale Freedom boards because they are low-cost, and I do not need a special debug device, as they have the on-board OpenSDA. It is using a small Kinetis-K20 which acts as JTAG SWD debugging probe. Why not using the Freedom board to program another board?
FRDM-KL25Z board programs another board
How many times have I seen this:
printf("Hello world!");
I have a strong opinion, and a rule for using printf():
“Do *not* use printf()!”
In this tutorial I explored how to use printf(), and this tutorial is so generic that it works for any processor/microcontroller. That flexibility is because I’m using Processor Expert. In case Processor Expert shall not be used, then some tweaks are needed. Here I show what is needed to have printf() working with the FRDM-KL25Z board. I use the UART0 connected to OpenSDA USB CDC for this.
In “Code Size Information with gcc for ARM/Kinetis” I use an option in the ARM gcc tool chain for Eclipse to show me the code size:
text data bss dec hex filename 0x1408 0x18 0x81c 7228 1c3c size.elf
I have been asked by a reader of this blog what these item numbers really mean. Especially: what the heck is ‘bss’???? 🙂
Eclipse has a nice feature to ‘shut up’ dialogs: In many dialogs I can select an option so that dialog does not show up again:
‘Dont’ show Again’ in Dialog
But what if I change my mind later on and what to have this dialog to show up again?
It happens to me many times: I’m stepping with the debugger through my code, and ups! I made one step too far!
Debugging, and made one step over too far
What now? Restart the whole debugging session?
Actually, there is a way to go ‘backwards’ 🙂
Continue reading
“As an engineer, you should ask for the best tools available. Spending money for better tools can make the difference between finding a problem quickly, or wasting days or weeks, and ultimately failing a project.” (unknown)
I had to learn it the hard way: some ‘hard-to-find-problems’ sometimes only can be found with some amount of luck, or with using a good trace solution. CodeWarrior already supports trace, such as using the MTB on the Cortex-M0+. But with this I’m limited to the on-chip trace buffer or on-chip RAM, which is better than nothing. But to solve the real hard problems, a bit of more power and memory is needed. And here where the P&E Tracelink comes into play: with 128 MByte trace buffer it would allow me to record a lot more trace data :-).
I’m using Version Control Systems like Git and SVN on a daily base. Because this gives me the opportunity to revert my changes and go back in time in my project. A VCS is incredible useful as well if I have deleted files or settings: restoring it is just a matter of a few mouse clicks.
But even without using a VCS, Eclipse has a built-in simple version control system: the Local History.
Eclipse History View
MCU on Eclipse 