Reviews, tutorials and the latest news about embedded systems, IoT, open-source hardware, SBC's, microcontrollers, processors, and more
Here’s a video of another Android tablet, a 10″ tablet made by Foxconn, aka Hon Hai Precision Industry Company. There seems to be quite a few tablets coming on the market (See Allgo Tablet) that should keep the prices down.
If you’re using ucLinux, you may get kernel panic errors coming out of nowhere. There may be several reasons (buffer overflow, out of memory..), but the most common is stack overflow for the process or one of the threads. To increase the stack size of a flat binary you’ll need to adjust the LDFLAGS as follows:
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LDFLAGS+=-Wl,-elf2flt="-s65536" |
This will set the stack size to 64KB. To change the stack size of a thread (e.g. 32KB below), you’ll need to set the stack size attribute:
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pthread_attr_init(&attr); err = pthread_attr_setstacksize(&attr, 32*1024); if (err) { printf("pthread_attr_setstacksize returned non-zero: %s\n", strerror(errno)); } err = pthread_create(&pthThread, &attr, thread, NULL); |
How to detect which thread suffers from stack overflow? First, you can check your code for recursive function calls and local variables (especially arrays) both of which will be added at runtime to the stack to estimate what should be the stack size. So if you have large arrays you may use a pointer + a call to malloc instead. If this can not fix […]
Currently digital signage implementations are mainly proprietary, and that means once you choose a vendor you are stuck with it, unless you completely change your network and the way you manage your content or handles separate systems. If the digital signage industry really wants to take off some standards are needed. One of the first standard for digital signage has been released by POPAI (Point of Purchase Advertising International). This first standard is to promote interoperability between different providers by defining Screen Media Formats (Click to open the standard) basically telling which video and audio codecs and containers (“Wrappers”) and which and picture formats should/could be supported by digital signage players and providing different levels of standard profiles and extended profiles a bit like it is done in MPEG-4 specifications. POPAI also used to provide some media samples to test your system previously available at www.popai.com/DS/ContentSamples but the link is […]
Here are the step I followed to install two distributions of Linux: Install the first distribution normally with GRUB in the MBR. While installing the second distribution make sure to set GRUB in its root partition. At this point the second distribution should not be available in GRUB Boot loader, login in the first distribution as root and edit /etc/grub.conf and add the following lines: Linux Distribution 2 root (hd0,2) chainloader +1 Save and restart your PC you should have 2 choices in GRUB, select “Linux Distribution 2”or whatever name you gave in grub.conf and this should start the second Linux distribution.
To list large files in a directory and subdirectories
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find /home/user -type f -size +10000k -exec ls -lh {} \; | awk '{ print $NF ": " $5 }' |
This command looks for files larger than 10MB in /home/user directory and displays the result as follows: /home/user/largefile1.tar.bz2: 32M /home/user/bugzilla.sql: 21M
To use vi as an hexadecimal editor: vi doc.txt [esc] :%!xxd
One of my reader had issues running Thin-clients ENTC Encore-1000 based on EP9307 and wanted to update the firmware in his systems. So I’ll explain how to access Linux, Windows XP or any other operating systems using a thin client based on Cirrus Logic EP9307 hardware. This is for reference only, and the performance may not be suitable for your environment/setup. One PC (server) is needed to run VNC (Virtual Network Computing) server for each remote desktop (i.e. each thin client), then the thin client can run the software without hard disk by just using the network connection. This can be used for checking emails, browsing internet, office applications, etc.. All resource heavy tasks are done on the server side whose specifications may be chosen to match the applications requirements. I’ll explain how to use Linux, but Windows XP (or any other operating systems for that matter) could also be […]
Ok, the title is a bit over the top but the Allgo tablet reference design running android would only cost around 35 USD to manufacture (15 dollars for the board, 15 dollars for the touch screen display and 5 dollars for the battery). So you’d be able to browse the web, read e-books, flicker through your pictures and access a wide range of applications through Google app store for less than 100 USD (retail) compared to the IPAD retail price of 499 USD that would seem like a bargain even though the performance is not as good as the IPAD (but still acceptable) as you can see in the video below.
