The good thing with the internet is: it allows engineers to collaborate. And here is an example: Marc is a reader of this blog had a problem with the I2C hardware of a Freescale Kinetis ARM microcontroller. In his case, the I2C bus could be stuck, and there seems no way to reset it with the I2C hardware on the microcontroller. So a solution would be to reset it with software instead.
Bit Banging Software I2C Driver
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 ;-).
Sumo Robot against Dummy Bot
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.
Zumo Sumo Battle
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:
Happy Roboting 🙂
For my RNet stack I need a way to identify nodes in the network using a unique address. What I need is Media-Access (MAC) address. Base on such a unique address I can assign short addresses (e.g. with a DHCP or similar protocol to automatically assign shorter network addresses). So how to uniquely identify my network nodes?
The Freescale Kinetis microcontroller have nice feature: they have a Unique Identification Register (UID) which would be a perfect fit for a MAC address :-).
UID Output
Usually, there are two flavors of Sumo robot competition:
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.
Accelerometer Remote Controller
For the INTRO Zumo robot I have three wireless options: Bluetooth, nRF24L01+ and IEEE802.15.4 with the Freescale MC1320x transceiver. For the nRF24L01+ I have developed a simple radio network stack which I can use with the MC1320x transceiver too.
MC1320x and MC13213 SRB Board
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 🙂
Two FRDM-KL25Z with nRF24L01+ Transceivers
So this tutorial is about using a terminal connection between my board and my host (e.g. a notebook) to read and write text:
Color Text in PuTTY
Yes, I have been busy with all the different ARM Cortex Mx cores I’m using in my projects. But beside of the ‘ARM domination of the world’, there are other interesting processors out there. While the ARM cores have added DSP (Digital Signal Processing) capabilities blurring the boundaries between pure MCU and DSP processors, there is still a place (or niche?) for specialized DSP processors. The power of such processors is in the domain of fast signal processing, e.g. for intelligent power switches or for advanced motor control.
TWR-56F8400 Board and Box
Wondering how much heap is used by Eclipse? Using the menu Window > Preferences there is a setting I can enable: “Show heap status“:
Show Heap Status in Eclipse
MCU on Eclipse 