Debugging is usually a ‘stop-inspect-continue’ process. That does not work very well for watching a system which continuously changes its state. For this usually I toggle an LED, or write things to the console to watch with a human eye what is going on. But there is something very powerful in the CodeWarrior debugger too: to display variables and memory content while the target is running.
Variable Live View
I have a project working, and then I want to do a copy. Unfortunately, this is not as simple as it should be :-(. In order to copy a project with all the settings, some knowledge about the internals of the project structure is required, which is the topic of this post.
In “Copy my Project” I was using a ColdFire V2 project which is not an easy case, as is using a Target Task to flash the microcontroller. Fortunately, all other targets in CodeWarrior for MCU are *not* using target tasks :-). With little help and preparation, a copy a project is not that difficult to do. I’m showing how to do this with the FRDM-KL25Z project I have created in this post.
Sometimes I show to much in a tutorial: only writing something to the UART? Sounds boring, so why not adding tasks, LEDs and a full shell implementation to the mix as in this post? Yes, definitely too much to start with at the beginning :-(. So less is more, and if it is just about the UART. And I promise: it is doable with around 50 lines of application code :shock:.
AND: I admit, this post title is a trap ;-). It is not about printf(). But it *is* about using the UART on the KL25Z Freedom board and to do things like printf(), and even more. Trust me. It is about how to write *and* read from the UART. While I’m using here the Kinetis-L ARM Cortex-M0+ KL25Z Freedom board, it is applicable to any other Kinetis device.
USB has two sides: if it works, it is great :-). If it does not, it is really bad :-(. It took a while in the desktop and PC world until USB for common devices (mouse, keyboard, memory sticks, …) was working without issues. But ‘non-standard’ devices like a USB debugging probe/cable are not of that kind of category.
Occasionally I run into USB driver issues in my class. So this post is about identifying the different USB driver parts for the P&E OpenSDA, P&E OSBDM/OSJTAG and P&E Multilinks. And how to install the drivers manually if something is not going well.
Many new notebooks do not have a serial port any more: everything is USB. This can lead to problems (see USB or not: CDC with Processor Expert) as many embedded targets use normal RS-232. In my classes I’m using the Tower boards: some Tower boards have an on-board 2 pin RS-232 header, e.g. the Tower TWR-MCF52259. Others like the TWR-K60N512 use the added TWR-SER board. The Tower boards have as well a USB capable S08JM60 which is used for debugging (OSBDM/OSJTAG), so why not using the OSBDM microcontroller as Serial-to-USB gateway?
It is one of these long weekends which allow to catch up on many things. One thing I finally completed was the move to FreeRTOS V7.1.1. With this I did some tests using the Tower boards, including the Kinetis one. So I have rebuild my Kinetis K60 application and was ready to flash the device. But then to my surprise I got this dialog:
Device is secure. Erase to unsecure?
Freescale S08 controllers have an internal clock generator (ICG) which allows the device to run without an external clock signal. But as devices differ, they need to be calibrated and trimmed. The microcontrollers are usually trimmed in the factory. How can I trim it myself if I need something better?
In many cases I do a full erase-flash-debug cycle: I get my embedded microcontroller flash completely erased and then programmed with my application. Well, that does not work that way if I program with a bootloader. Yes, I can flash the bootloader and then load my target application with the bootloader, but that’s not the scenario I want to use in the development phase. I want to flash my application and keep the bootloader on the target. This means: I need to do erase and program a part of the memory. But how to do this?
The update 1.0.0 for the MCU10.2 release has been published on the Freescale CW MCU V10.2 Updates & Patches web site. Downloading the 500 MByte zip file and installing the update will take a while. After downloading I select Help > Install New Software … and specify the archive file.
Note: In general uninstalling an eclipse update is not possible. If you want to keep our original MCU10.2 on the side, then follow this trick: Copy your existing MCU10.2 installation folder and rename it (say to ‘MCU10.2_without_update’). Then apply the update to the normal MCU10.2. If you want to revert to the version without the update, simple delete the updated installation and rename the one without the update again. No need to reinstall things again. And you can use both the updated version and the normal version in parallel too: simply launch the eclipse\cwide you want 🙂
Time to read the release notes and dig into what has been changed and improved.
Creating an eclipse managed make project with MCU10 is easy: Starting the wizard with File > New > Bareboard Project and after a few clicks I have a project. I don’t need to worry about all the files in the project structure, until……..well, until I need to put the files into a VCS.
MCU on Eclipse 