Tag Archives: PI

Linux

Setting up a Pandaboard for KWin development

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The Pandaboard is a nice little ARM powered device which is meant for development and suited for example to test KWin on real OpenGL ES hardware. This weekend I decided to set it up again, I had done it before, I had installed KWin on the PI, so I’m not a complete NOOB for ARM hardware. I wanted to test a few things and see how the latest changes to master do on a non x86 architecture.

I got the memo about Linux is for normal users and not for LEET, but I do not understand why it has to be so difficult to setup a device which is meant for development. In the past it was as simple as dd an image to an SD-card, plug it in and done. Well those times are over.

My requirement for a base distributions are rather small:

  • Up to date kdelibs, because compiling is slow on the device
  • Working drivers for GL hardware

With this combination we can rule out most distributions like for example Debian (issues with both) or openSUSE (no drivers). I decided to try Linaro 13.02 which offers an image for Pandaboard and is Ubuntu 12.10 based, which means we can easily install KDE packages.

Linaro is still rather simple: dd to SD card, plug in and go. Just that you don’t get any output on the screen. I already thought my Pandaboard was broken. What’s a little bit tricky is that the Pandaboard has two HDMI connectors (one as HDMI, one as DVI) and at least openSUSE reports that only the real HDMI works. But with Linaro I did not get anything on either screen or TV.

So I had to connect to the Serial port to get some output. And look there: it boots. Once I was logged in I was able to figure out that the system is pretty basic, e.g. no X installed. But even after installing X I did not get anything on the screen: it complained about missing /dev/fb0. That was then the point where I considered trying a different distribution. (Search did not help).

Next choice was Kubuntu. This also used to be rather simple: dd to SD card. Downloaded daily build of 13.04, dd to SD card, plugged in and screen turns on. But instead of starting the system, the installer is started. Well since 12.10 you need to install. Obviously the system is not able to install to the SD card which is plugged in. So I got an USB stick, dd to stick, plugged in and nothing. The pandaboard doesn’t boot from USB stick. Now it got difficult: search for a second SD card. Found one, dd image to the second card, moved the first SD card to a card reader, plugged everything in and installed to the SD card at the card reader.

After installation, I swapped the SD cards, plugged in and nothing. System doesn’t boot. Well maybe the system expects at a different device, so I plugged the card reader …read more
Source: FULL ARTICLE at Planet KDE

Business, Finance, Occupation & Industry

Zilog Announces the New MCU Based Battery Charging Reference Design

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By Business Wirevia The Motley Fool

Filed under:

Zilog Announces the New MCU Based Battery Charging Reference Design


High-Performance Design Solutions Offering Digital Improved Battery Management Technology

MILPITAS, Calif. & BIEL, Switzerland–(BUSINESS WIRE)– Zilog, a wholly-owned subsidiary of IXYS Corporation (NAS: IXYS) and a pioneer supplier of application-specific, embedded microcontroller (MCU) system-on-chip (SoC) solutions for industrial and consumer power management applications, is introducing its new Buck Converter Battery Charger Reference Design that employs Zilog’s Z8F042A MCU to control a step-down DC-DC converter (also known as a buck converter) that acts as a regulated power source.

This buck converter battery charger hardware is capable of regulating charger output in a number of modes, such as constant voltage or constant current with set current limits. The charger can be viewed as a complete control system. The type and capacity of the battery determines the mode of operation of the battery controller. The voltage and current set points are also determined by the type and capacity of the battery. All battery control loop operations can be controlled by the user via the Z8F042A MCU‘s UART block and feedback is provided in the HyperTerminal console. Additionally, LEDs provide a visual status of the charging process.

This low-cost reference design demonstrates a lithium ion battery charger consisting of a Z8F042A MCU and a buck converter. The charging process utilizes the highly accurate ADC peripheral and alternates between current and voltage monitoring which is controlled in the background software routine, allowing for the UART to be processed in the main function. With the provided hyper terminal GUI, the user can enter desired set-voltages and set-currents. A proportional/integral (PI) control loop is used to charge the battery and to monitor the battery voltage after the charging process is completed. To save memory resources, the provided UART does not implement the STDIO.H libraries. Instead, a simple UART using only integer values is used.

“This battery charger reference design allows operation either via UART or an external 5-15V power supply. The advantage of this battery charger implementation is in the efficient utilization of the Zilog MCU resources, allowing for low cost digital power management solution, which is flexible and adaptable to different batteries,” commented Steve Darrough, Zilog’s VP of Marketing.

Zilog’s Buck Converter Battery Charger Reference Design is now available for customers that place orders through Zilog’s online store. …read more
Source: FULL ARTICLE at DailyFinance

Linux

Help request. FTP user to var/www/html

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By Pinkfloyd

Hi all.

I appologise this is my first post, I will gladly have a further look around to see if this has been posted elsewhere, but so far it has not, or it doesnt quite explain in full what I need. If anyone here can help me out, I would really appreciate this. I want to make sure I do this right, as in the past I made a huge error and messed up my server. 🙁 🙁

I have two servers.

1, is our online dedicated server for mainly gaming, but I also use it as a hosting site for very basic webpages and a forum. This is on Centos 5.
2, My second server is a raspberry PI which I am using to test and learn from which is on Debian at home.

I fully understand that these are two very different distro’s but I am hoping what I need to do, can apply to both. All I want to be able to do is create a user, which has full read/write access ( and also be able to change a subfolder’s acess ( to 777 for example ) to the var/www ( PI ) or var/www/html ( Centos ) folders using a client FTP application from a Windows PC, such as Filezilla.

As an example from my Raspberry PI, I wanted to try this from root:

Code:
chown -R piweb:piweb /var/www/

I assume, this on Centos would be :

Code:
chown -R webuser:webuser /var/www/html

But im not so sure if this is right, or if there is a better way to do it? Any help would be great, thanks for your time.

Thanks

Source: FULL ARTICLE at The UNIX and Linux Forums