There is one week left until all the Sumo robots of the Infotronic course at the Lucerne University of Applied Sciences and Arts will enter a tournament. The robots have to pass a simple tests before they can enter the tournament: to push a ‘dummy’ robot outside the ring. This simple test is used at tournaments to avoid ‘passive’ robots just sitting in the middle of the ring ;-).
The semester is approaching its end, and students are making great progress: with added infrared and ultrasonic sensors, the robots are able to detect the other robot (more or less ). Additionally the RNet stack adds extra remote control capabilities.
Things are very much in the testing phase, and some robot (or operator?) failures are really funny For sure much more advanced moves compared to previous week. Including extra benefits like a robot bringing a bottle of water! The following video hopefully gives an impression:
Usually, there are two flavors of Sumo robot competition:
- Autonomous: no communication to the robot permitted after the start.
- Remote-controlled: there is a wireless remote controller driving the robot.
Just for fun, I have implemented a wireless remote controller application for my Zumo Robot using the Freescale SRB (MC13123) board. I’m using the Freescale MMA7260Q accelerometer on the SRB board to control the robot.
The INTRO course is progressing fast, with a lot of information passed on how to build a successful mini Sumo robot based on the Freescale FRDM-KL25Z and a modified Pololu Zumo chassis. The PID control loop implementation for speed and position finally starts to work properly with the help of FreeMaster. Things are not perfect yet, but the robots get better from day-to-day.
I was searching the internet for an open source network stack for my nRF24L01+ transceivers. But these stacks were either too heavy or had a restrictive or not really non-open source license behind it. I was very reluctant to start with something I think already should exist. Two weeks ago I decided that I just do it from scratch, and here I am: I have the basics working
So this tutorial is about using a terminal connection between my board and my host (e.g. a notebook) to read and write text:
Are you using IAR tools and you are jealous looking at what others can accomplish with Eclipse? You wish you could use your IAR build tools but taking advantage of Eclipse too?
I do not want to start a religious IDE war here ;-). At least for IAR, there is a way to bring both worlds together: having IAR build and debug tools integrated in Eclipse :
For the Eclipse and Processor Expert lovers of this world: there is another Eclipse based IDE you can use: ThunderBench made by Emprog:
They support a range of ARM based devices, including the Freescale ones I’m using. So I downloaded the v3.24 30 day trial from their download page last week. Finally I have found some time to try it out. Could this be an alternative to use my Freescale FRDM boards with Processor Expert?
If you were wondering why I am pushing the FRDM-KL25Z boards hard to the micro-amps, then have a look at this:
The five boards are the first set of prototypes with a FRDM-KL25Z for a battery operated wireless sensor network based on the nRF24L01+ 2.4GHz transceiver.
Freescale might not have thought about this: how to use Freescale boards and silicon to develop for non-Freescale silicon?
I tinkered around using the FRDM (e.g. FRDM-KL25Z) board as a general purpose programming or debugging device. See the links to the posts at the end of this article. I have used it to program and debug other Freescale ARM processors. It requires board changes and the usage of a different OpenSDA firmware which has its own limitations (no USB CDC serial bridge). But for about $15-20 I have a device to program my own external boards :-).
If you are using Keil tools, then the good news is: With CMSIS-DAP you can debug any other (even non-Freescale) ARM device as long it is supported by the IDE :mgreen:
The FRDM-KL25Z is a great board: inexpensive (around US$15), small form factor, has easily accessible pins, and has a low power (capable, at least) microcontroller, and comes with an embedded debugging interface. So why not using this board right away ‘as is’ for a low power battery operated device? Great idea, you think? Yes, I thought too. Only to find out that the board needs 20 mA out of the box.
The good news is: It is possible on a week-end to get this 150 times better down to 132 μA, with an RTOS running all the time :-). I invite you to join a journey with board modifications, jumpers, schematics and many multimeter pictures ;-)….
Microsoft has released the Windows 8.1 Preview. So you can try out the next update of Windows 8. In short: Do NOT use Windows 8.1 Preview if you are using a Freescale FRDM board! Otherwise you will not be able to change the OpenSDA firmware (MSD or debug application).
Well, I have not used it personally: I never use ‘test’ or ‘preview’ versions on my ‘production’ machine. It is ok to try things out on separate ‘scratch’ machines, but not on something I need to have stable for my work. Well, some of the students in my INTRO class were not able to resist and downloaded and installed Windows 8.1 Preview on their machines. With the result that the OpenSDA Bootloader does not work with Windows 8.1 Preview:
It seems that the problem exists as well with the Windows 8.1 ‘final’ release.
In case you have this problem with the FRDM boards: You are using the FRDM bootloader mode (it shows up as BOOTLOADER) or the MSD mode (e.g. it shows up as FRDM-KL25Z) (see OpenSDA on the Freedom KL25Z Board) and it does not respond any more, or does not work as expected, then read on…