A while back I wrote two articles about Semihosting: “Semihosting with GNU ARM Embedded (LaunchPad) and GNU ARM Eclipse Debug Plugins” and Semihosting with Kinetis Design Studio. With using the GNU ARM Embedded (lauchpad) in my Kinetis Design Studio, time for a ‘summary’ post :-).
Semihosting Output in Console
The Teensy is a great and tiny board (see “USB CDC with the Teensy 3.1 Board“), but it lacks real SWD/JTAG debugging capabilities (see “Hacking the Teensy V3.1 for SWD Debugging“). The Freescale Freedom boards are great, but for many applications too big, and have potentially too many components on it. So what about building a breadboard friendly tiny board which *has* SWD debugging ability *and* can be used to debug another boards?
So here is a working prototype based on the FRDM-K20D50M:
FRDM-K20D50M used as debug probe
If you have read my article “Serial Terminal View with Eclipse Kepler“, then you are aware that using a Terminal view to a serial connection (COM port) under Eclipse Kepler is pretty much broken. I’m moving some of my projects to the more recent Eclipse Luna release, and the good news is that support is back 🙂
Terminal View with connection to board
The days are getting longer, cherry trees start blooming while the Alps are still snow-covered in the background:
Mythen und Lauerzersee (click to enlarge)
In my classes I’m mainly using the Freescale FRDM-KL25Z board, as it provides the best value for the money, and 128 kByte FLASH with 16 kByte of RAM is enough for many smaller projects. I do have as well the FRDM-KL02Z Board (32 KByte FLASH, 4 KByte of RAM) which is an inexpensive board to evaluate the smaller KL02Z microcontroller. Because someone reported a problem not being able to use the UART over OpenSDA/USB-to-CDC bridge, I have created a demo project which communicates with a console on the host.
FRDM-KL02Z Board
P&E has upgraded their GDB implementation and interface used in combination with the GNU ARM Eclipse plugins: they support now advanced flash programming options plus the ability to attach/connect to a running target :-). This update is available as Eclipse update.
Advanced Options
For a project I want to use the Teensy 3.1 board (see “Hacking the Teensy V3.1 for SWD Debugging“) in USB CDC mode: that way the Teensy board can connect to the host and exchange data or attach a console to the Teensy board: that way I can connect the Teensy over USB to the host use the USB as communication interface:
Teensy with Octo WS2811 Board
Frequent readers of this blog know: I’m using Processor Expert in most of my projects with CodeWarrior, Driver Suite or Kinetis Design Studio. With the move of Freescale to Kinetis Design Studio and the Kinetis SDK with Processor Expert, there is an opportunity for our voice to be heard in a survey Freescale now runs about configuration tools and Processor Expert.
Processor Expert
Happy Surveying 🙂
In one of my earlier posts (“Using the DHT11/DHT22 Temperature/Humidity Sensor with a FRDM Board“) I’m using the DHT11/DHT22 temperature/humidity sensors with the FRDM-KL25Z board. These sensors are very inexpensive, but have limited measurement range and accuracy. As pointed out by a reader of that article, Sensirion (a Swiss company :-)) has good sensors too, and I decided I would like to try the SHT11 sensor:
SHT11 Sensor
There are cases where my application runs find for days, weeks or even months, but then from time to time there is an application crash. Yes, the watchdog will recover it, but still it would be good to know what happened? One solution would be to hook up a trace probe (like the one I have described in this post: “First Steps with the P&E Tracelink“). But having such a trace probe attached all the time is first not cheap and second not always possible. So what if the application would leave ‘breadcrumbs’ behind which would tell me the flow of the program leading to the problem? I have found a functionality in the GNU tools which seems not be widely known or use, but is incredibly helpful in such cases.
So what if I could get a log like this telling me which functions get called by whom?
{ 00000E88->00000DA0 ???->DEMO_Init
} 00000E88<-00000DA0 ???<-DEMO_Init
{ 00000E8C->00000D40 ???->DEMO_Run
 { 00000D62->00000CE8 DEMO_Run:0x0022->decide
 { 00000D0E->00000C60 decide:0x0026->calcValue
 } 00000D0E<-00000C60 decide:0x0026<-calcValue
 { 00000D16->00000CA0 decide:0x002E->getValue
  { 00000CC6->00000C60 getValue:0x0026->calcValue
  } 00000CC6<-00000C60 getValue:0x0026<-calcValue
 } 00000D16<-00000CA0 decide:0x002E<-getValue
 } 00000D62<-00000CE8 DEMO_Run:0x0022<-decide
 { 00000D62->00000CE8 DEMO_Run:0x0022->decide
MCU on Eclipse 