Browse: Page 2
By Chelmis Muthoni on March 3, 2017
I recently came across Scratch, an ingenious free programming language and online community where you can create your own interactive stories, games, and animations by MIT. At first, I installed it in Ubuntu using the command “sudo apt install scratch”. It was great, until I realized that there was a difference between that editor and the online one. The online editor saved .sb2 files while mine saved .sb files so I could not view the projects I had done online on my offline editor. For this reason, I decided on Scratch 2 Offline Editor.
To install Scratch 2 on Ubuntu, run the following commands from your terminal.
- Download Scratch 2 Offline Editor.
- Download the Adobe AIR shell script file and install it by running the commands:
wget -O adobe-air.sh http://drive.noobslab.com/data/apps/AdobeAir/adobe-air.sh
sudo chmod +x adobe-air.sh
sudo ./adobe-air.sh
- Run adobe air installer
sudo Adobe\ AIR\ Application\ Installer
- Navigate to the location of your scratch download and select the scratch.air file.
- Install scratch in /opt which is the default install location
Happy scratching 😛
Posted in Embedded systems | Tagged Scratch |
By Karibe on January 27, 2017
In my quest to look for better introduction to computer programming training methods for the young groups, I landed on the MIT Scratch on the web. I realized they have an offline version of scratch 2.0 which is great. I installed it in Ubuntu with the command “sudo apt install scratch”. The teaching/learning philosophy of Scratch is awesome, but I want to teach using real world examples. The Freedom KITs from NXP make my life very easy when I want to hack together some hardware examples for teaching. So I wanted to know if I connect the serial port on the KIT to scratch so I can control the board or monitor inputs from the board in Scratch. Of course I am not the first person to think of this, there are already several people who have interfaced several boards with Scratch, since before version 2.0. But in this version of the program, there is no direct way of Scratch communicating with hardware. It broadcasts and listens using HTTP, and I need a helper program to interface with Scatch via HTTP and the serial port at /dev/ttyACM0. I have seen some JavaScript HTTP extensions, but I thought Python is the way to go since I am already investing time in it teaching University first year students. First thing I do is google Scratch python interface example and I come up with a simple script. The Scratch protocol is documented on the wiki. It’s very brief but effective. It’s a 4 byte size field followed by size bytes of a message msg as:
<size: 4 bytes><msg: size bytes> Continue reading “Controlling and monitoring FRDM-KL25Z from Scratch using a python interface”
Posted in Embedded systems, Scripting | Tagged frdm-kl25z, hardware, python, Scratch |
By Karibe on January 20, 2017
I installed Ubuntu on my HP probook 6460b and everything apart from the fingerprint scanner (not really useful) worked out of the box. Lately I was shocked to see that Bluetooth wasn’t working. I tried to go to the settings GUI and click the connection toggle button, but it would toggle right back to the off position, meaning it was not possible to make a connection. Nothing the GUI can help with here. The HP computer was also not visible on my phone’s Bluetooth devices list.
rfkill list
0: hp-wifi: Wireless LAN
Soft blocked: no
Hard blocked: no
1: hp-bluetooth: Bluetooth
Soft blocked: yes
Hard blocked: no
2: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
So from the list Bluetooth is blocked by rfkill, no wonder I cannot connect in the GUI. Continue reading “Bluetooth not working in Ubuntu 16.04: blocked by rfkill “
Posted in Uncategorized |
By Lexy Andati on July 21, 2016
For a while, I had been working on my first “Real” embedded system code on an ARM Cortex m4 microprocessor, the MK60N512 , which comes with the NXP towerkit, TWRK60N512 , and obviously, my first task was to make at least one LED blink on the board. Seeing as I was used to the easy way out, (read Ardu… 🙂 ), I didn’t think it would be such a huge task. But as it turns out, there is a whole LOT of things that needed to be done before actually making the first program. Luckily I had an instructor and the oh so glorious Youtube.
Ok enough with the quests and conquests story. If you would like to work on the Cortex m4 processors on a ready board/ tower you need a couple of things. These include
- The microprocessor data sheet
- The board’s schematics
- The board’s user guide
- The peripheral modules quick reference guide.
The data sheet shows all available registers, the memory map of the general K60 micro-controller. Schematics show the routing of the micro-controller pins in the printed circuit board, this is especially useful because it will help you know which pin is connected to what external circuitry. The user guide just gives the general overview of the kit, the features what can be used and for what purpose. The quick reference guide gives a summary of some configurations possible on the board and some examples as code snippets, just to show how one may program the board.
Continue reading “TWRK60N512 BliNk bLiNk BLINK already!!”
Posted in Embedded systems | Tagged ARM, microcontroller, twr-k60n512 |
By Karibe on July 20, 2016
Japanese mobile giant SoftBank has agreed to acquire British chip designer ARM in a deal worth £24.3 billion (about $32 billion).
Sprint’s parent company just bought ARM, the biggest smartphone chip designer
Posted in News | Tagged ARM |
By Chelmis Muthoni on July 18, 2016
OpenSCAD is an awesome parametric 3D CAD modeling software that focuses on allowing you to describe the model in a scripting language and renders the output onscreen. Because the model is described in code rather than objects, it can easily be changed, updated and parameterized. The part can be customized without changing much in the code, rather defined variables can be adjusted to get the desired size and shape. For electronic components, this is very useful. Think about some simple 3d model for pin headers. If you have a model for 2.54mm pitch header, you only need to change the pin size and pitch to generate 1.27mm pitch header (or just pitch if pin size is calculated from pitch), and that way much time can be saved and code reused. Even more interesting, a parameter for number of rows and columns can be used to generate any pin header from single row, dual row, one with 2 positions as a jumper to a 40-pin header for board to board connection. You can also have a parameter for straight versus angled header. Variables are also help in openscad when it comes to having parameters at the beginning of code which can be used to select what to render in case several modules exist in one project. The limit is your imagination and math with OpenSCAD. To demonstrate this, look at the files on this thingyverse thing
To get the model on KiCAD, first we have to render the model by pressing F6, then export STL file. We can then import the STL file into Wings3D and add colors and materials on different parts to represent realistic visualization and export as VRML file which can be set as the 3D file for a component in pcbnew in the footprint editor window. STL file format has no units, so in case the model is larger in KiCAD, you can through the settings scale it as required.
Posted in Embedded systems | Tagged KiCad, openSCAD |
By Karibe on July 16, 2016
I had my good share of datasheet reading with Joe, one of our many interns at work. We are working on this purely bare-metal serial bootloader project. The first milestone is to have a board bring-up firmware with a working start up script, linker script and system clocks initialization. We then added a single LED for the embedded hello world. As soon as we can blink, we want to communicate with the computer, so UART is a good start. The second milestone is therefore to have a working serial port configured with interrupts, transmit and receive buffers, and software flow control using Xon/Xoff.
So I whacked a quick UART configuration as follows:
- Configure UART0 pins: PTA1 as UART0 Tx, PTA2 as UART0 Rx by setting the port Pin Configuration Register (PCR) MUX bits to alternate function 2
PORTA_PCR1 |= PORT_PCR_MUX(2);
PORTA_PCR2 |= PORT_PCR_MUX(2);
Continue reading “Configuring Interrupts for ARM Cortex M0+ based Micro-controllers”
Posted in Embedded systems | Tagged ARM, cortex_m0+, interrupts |
By Karibe on July 12, 2016
I have been using evince, the default Ubuntu PDF viewer for as long as I can remember my first Ubuntu installation. Lately, it got me annoyed. The reason is simple, there is this large PDF datasheet for a micro-controller that I read which is over 1800 pages and whenever I open the index, its in expand all mode. I really love using the index to find the section/module I want to read about. The problem is I have to collapse all the index entries before finding the one I want by title. It would be so much easier if I could just be able to open the document with all the index entries collapsed.
Today I had enough, a quick search on the internet and I found an alternative reader, qpdfview, and installed it:
apt-get install qpdfview
Then right click on any PDF file, go to properties, the open with tab, and set qpdfview as the default viewer. To show the index or as they call it, outline, go to view->Docks->outline. Surprisingly, it opens the document with all index entries collapsed, problem solved. All text objects with hyper-links are also shown wrapped in a thin red box, which is very helpful. It also opens files much faster than evince. The invert colors view mode is great for my eyes too, but to give it to evince, this feature was also available. Loving reading PDF files yet again…
Posted in Documentation, Linux | Tagged PDF, ubuntu |
By Karibe on July 12, 2016
I have Kinetis Design Studio (KDS) version 3 installed on my Ubuntu 16.04 machine. I know I can use PE Micro gdbserver from the eclipse IDE interface, but what about putting it in a makefile somewhere because I am turning into an automation freak 😛
The reason I want this is simple, I am doing baremetal development for the FRDM-KL25Z NXP KIT and I want to use a makefile to automate everything. I only edit the code in Gedit. I could use OpenOCD, but the CMSIS-DAP firmware for the KIT doesn’t support a serial port through the debug interface, while other firmwares, including the PE micro one do, infact it supports all 3 things including a debug port, a serial port and an enumerated MSD Device.
so I looked for the file using locate command:
Continue reading “Running PE Micro GDB Server from Kinetis Design Studio Installation in terminal”
Posted in Embedded systems | Tagged debug, frdm-kl25z, Kinetis Design Studio, NXP, PEMicroelectronics |
By Karibe on July 6, 2016
Posted in Uncategorized |
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