Simple multi-meters probably will not give you an accurate AC reading (in AC mode) when checking the DC side of a rectification circuit.  You really need to use an oscilloscope.

It did not work because I could not disable intel video chipset in my uefi bios. :(

UPDATE to F30. and Fixed acpi (see grub commandine below)

NVidia driver issues still persist, but I finally debugged (and disabled) acpi consistent errors that had be plaguing me in F27.

I added a kernel boot param to my Grub2 commandline.

• acpi=off

Neutron Music Player Song Ratings: I needed to transfer all the 1000s of song ratings from an old android pad to a new one. I figured out how to access and restore the song ratings in the Neutron music player (Android) SQLite database.

See the SQL, database tables and how I did it.

I have started to get some useful sample/examples completed on my Raspberry Pi2. Here is the Schematic and Java code to control an RGB LED.

I also have examples for:

• controlling multiple GPIO pins with external transistor driven LEDs and Java Pi4J code that times their cycling.
• Pulse Width Modulation (PWM) control of GPIO pins and an RGP LED.

 These will be discussed in other posts.

[FIXED] The Gnome Bluetooth GUI via settings FAILS to pair with my HP Bluetooth Laser Mobile Mouse. This has not worked in the gui bluetooth settings app for a few versions (maybe F19).The problem is that the mouse does NOT have a pair code, and the it won't pair with '0000' or '1234'.

I figured out to manually pair it from the commandline without a pairing code!

use bluetoothctl on the commandline

use the following commands to connect to the MAC address...

Now that I have my Raspberry Pi2 working with Java, I need to draw up some schematics....

Here is how I downloaded & installed the latest Git version of XCircuit on my Fedora 21 workstation.

It includes all the Fedora Yum  RPM packages I had to install to get it to build from source - you might need others.

Getting Fedora 21 setup and configured to comfortably work with Java on my new Raspberry Pi2. My last entry desribed the install.

I will describe how I configured things to make it efficient to test and develop Java on my Pi2:

1. Boot to multi-user commandline (and how to start the graphical desktop if needed)
2. Samba shared directories
3. SSH without password from my workstations

I Got a Raspberry Pi2 ! It has a 900MHz quad-core ARM Cortex-A7 CPU  and 1GB RAM.

I first tried noobs with Debian and it ran out of the noobs box very well.  The noobs version of Fedora DID NOT because it was not built for the new version of the ARM processor in the Pi2. That was no big deal because thanks to user clivem on the Pi Forums an image was avaialble.  See the forum link for the details. It is a full F21 version that is called FIDORA.

It was very easy to get this working. It is Fedora 21 for the ARM, with full yum repo support including rpmFusion.

My Onkyo NR-5008 receiver had been showing signs of a well documented hardware problem for months.

• No speakers show up as being connected. 
• The network setting menu item is also grey'd out.

See http://www.avsforum.com/t/1455911/onkyo-hdmi-failures/180#post_24625838 for the details.

Since I am the developer for the Java implementation of the Onkyo eISCP, this is a big problem for me :(

After succesfully upgrading F20 to F21 using Fedup (on my server); my Owncloud CRON install was not working.

Cron entry looks like:

*/10  *  *  *  * apache php -f /var/www/html/owncloud/cron.php

So I tried it on the commandline and an error told me that the new
upgraded version of PHP had a change in the default setting (in
/etc/php.ini)  for always_populate_raw_post_data. It told me to set it to:

always_populate_raw_post_data = -1

The cron now runs without error.

Announcing PowerEYE, your own WebAPP to access & archive your Rainforest Eagle power meter data (privately) to your own computer.

http://powereye.webarts.ca

• Do you have a new smart meter from your power utility?
• Do you also have a Rainforest Eagle energy access gateway device to that talks to your meter and collects your power & energy usage data?
• Do you also want more infomation from your Eagle or have concerns about the privacy of sending your data over the internet just to see some detailed usage charts or download your data?
• Do you also have a UDI ISY-994 home controller that you want to control or send the Rainforest Eagle messages to?

Then this might be of interest to you...

F17 has not moved fully to systemd (as doc'd on https://fedoraproject.org/wiki/Systemd), so to change the default run level use the following commands:

Go to the non-graphical multi-user commandline bootup:

rm -f /etc/systemd/system/default.target;ln -s /lib/systemd/system/multi-user.target /etc/systemd/system/default.target

 go to the full graphical bootup:

rm -f /etc/systemd/system/default.target;ln -s /lib/systemd/system/graphical.target /etc/systemd/system/default.target

I just realized that my Apache Derby database had stopped listening on its DB port 1527.

It took a bit of tracing but soon found
that a Java runtime policy had changed to be more restrictive than
before. It now restricts java apps to create and listen to IP ports by
default.

The FIX:
add the follwoing to the end of the java.policy file in the jre\lib\security dir

grant {

    permission java.net.SocketPermission "localhost:1527", "listen";

};

Thats it. the derby network server now starts as usual.

I updated my Zoneminder installation to the latest version (1.27 master branch) from source at GitHub. My intention is to get the latest version that has an updated FFMPEG library and the libVLC. My original intention was to also building x264 and ffmpeg from source to ensure I have all codecs compiled in from the start.I did not have to do that because the Fedora20 Packages from RPMFusion already have what I needed (that makes life easier). I have done this before (see http://tom.webarts.ca) for by past experiences.

I am also re-installing the OS - Fedora20 to get the latest security updates.

The Zoneminder wiki has pretty good instructions. http://www.zoneminder.com/wiki/index.php/Documentation#Installation_from_Source
The forum also has a very good summary of installing from RPMs http://www.zoneminder.com/forums/viewtopic.php?f=9&t=19119

This post documents my steps