Rigi Schwinget (Picture: Roman Koch)
Every three years, there is the “Eidgenössisches Schwing- und Älplerfest” in Switzerland. A really big thing for us here. If you are not familiar with what this is, then have a read about the long tradition of Schwingen in Switzerland.
Wondering what “Schwingen” or wrestling has to do with a technology blog? It is about having fun with robots!
The ARM Cortex specification includes the ‘SysTick’ (System Tick Timer): a dedicated system timer which is intended to be used as time base for an RTOS. While technically it would be possible to use any periodic interrupt timer, I’m using as well the SysTick for my FreeRTOS ARM ports. And because Processor Expert includes a nice timer interface, I’m using the TimerUnit_LDD:
TimerUnit LDD for SysTick
While this is great for flexibility, it has its price in efficiency. That TimerUnit_LDD adds overhead. So I want to get rid of the TimerUnit_LDD and use a more efficient way.
As I was so pleased with the FRDM-KL46Z board, that I have ordered the Tower version of it, the TWR-KL46Z48M:
FRDM-KL46Z with TWR-KL46Z48M
What I missed so far was USB support for the KL46Z. So time to have a quick look at board(s) and to add USB support for it.
“A picture says more than 1000 words.”
I don’t know the source of that quote, but for sure it is true for every developer and engineer too. Engineers need to work a lot with numbers. But numbers can be transformed into pictures and graphs which can make complex things and relationships easier to understand. Verifying proper functionality of a PID closed loop controller or watching sensor values with a nice plot is definitely something very useful. Would it not be great to watch sensor data changing over time in a chart like the one below?
Accelerometer Graph
One way is to export data and then show it e.g. in Excel (which has been great chart functions). But even better, if this could be done directly with data provided from the target board? If you think this is hard to do, then I can show you how this can be done in a few steps with the help of a very nice tool: FreeMASTER 🙂
One of the ‘goodies’ of the FRDM-KL46Z is the Freescale MAG3110 magnetometer. The MAG3110 is a tiny 2×2 mm device:
MAG3110 on FRDM-KL46Z
What was missing so far is a Processor Expert component for it. This post is about closing this gap…
So far I have covered in this tutorial series how to install ARM GNU gcc, adding Eclipse, followed by adding GNU GDB debugger, and then adding Processor Expert. I’m using FreeRTOS a lot in my projects, and luckily there is a Kernel Awareness Plugin available for FreeRTOS for GDB in Eclipse. This tutorial is about how to install and use it.
Queues and Tasks
I covered in a previous tutorial how add ARM gcc to Kepler Eclipse to build a DYI toolchain. I’m using Processor Expert a *lot* in my project, because it simplifies and speeds up the development of my embedded applications. What is missing so far is how Processor Expert can be added to Eclipse. As Kepler is as of this writing the latest Eclipse version, this tutorial is using that version.
❗ Eclipse Luna is *NOT* supported in Processor Expert 10.4! Eclipse Luna is expected to be supported in Processor Expert 10.5 coming out in 2015! So if you are using Processor Expert 10.4, then make sure you are using Eclipse Kepler.
Processor Expert Project in Kepler Eclipse
I finally completed my project turning the FRDM-KL25Z board into a USB mouse device :-). The form factor and the capabilities of the Freedom board makes it a great board for implementing it as a ‘custom mouse’. All what I need is the USB stack running on it and have it acting as USB HID Mouse device.
FRDM-KL25Z enumerated as USB HID Mouse Device
A week ago, the updated FreeRTOS V7.5.0 has been released on FreeRTOS.org. So time to have my Processor Expert FreeRTOS component updated as well :-).
FreeRTOS V7.5.0
This is the third part of a tutorial series how to ‘do-it-yourself’ a tool chain for the Freescale Kinetis microcontroller, with the FRDM-KL25Z as example. The tool chain is using GNU ARM gcc plus Eclipse Kepler release. So far I have the following parts:
So far things are very generic. But with debugging it means different hardware, and different hardware connections. And for this connection we need a GDB Server.
Eclipse CDT features a GNU Debugger (GDB), and this is what I want to use here: debugging my microcontroller with GDB inside Eclipse. In order to debug the microcontroller, I need two other things: a GDB Server and a Debug Probe.
GDB with GDB Server
