Multiplexed SSH sessions for quicker connection

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If you need to open multiple SSH connections to the same host, it can get tedious to re-authenticate for every one. And even with public key authentication and no password, the extra channel eats a bit of bandwidth. The solution is multiplexed SSH sessions: Authenticate once, and the following connections to the same host goes over the same session. It’s dead easy to set up:

In your ~/.ssh/config file add the following lines. (Make sure that file has user permissions only, i.e. 600).

Host *
   ControlMaster auto
   ControlPath ~/.ssh/master-%r@%h:%p

It takes effect immediately. SSH twice to the same host to verify.

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For some unknown reason, the default character set in Debian 7 (“Wheezy”) is different to Ubuntu 12.04 (“Precise Pangolin”). The former uses latin1, while the later utf8. (This could also be down to other local configuration I’m not aware of). The difference between the two is rather subtle, and might go unnoticed. One visible effect is when using letters with German umlaut or Scandinavian specific letters in ordered text. For example, the Norwegian letter Å (aring in HTML) is the last of the alphabet, but when using latin1, it is interpreted as an A (or possibly double a: aa) and ordered first. See this bug report and discussion for more details and examples.

The character set is specified in multiple places in the MySQL DBMS: On the database, table and for the client, server, connection, result set and underlying system. To view the current settings, these two commands give an overview (see here for details):

SELECT * FROM information_schema.SCHEMATA;

The output will be something like:

| def          | information_schema | utf8                       | utf8_general_ci        | NULL     |
| def          | test               | latin1                     | latin1_swedish_ci      | NULL     |
| def          | myTESTdb           | latin1                     | latin1_swedish_ci      | NULL     |
| Variable_name            | Value                      |
| character_set_client     | utf8                       |
| character_set_connection | utf8                       |
| character_set_database   | latin1                     |
| character_set_filesystem | binary                     |
| character_set_results    | utf8                       |
| character_set_server     | latin1                     |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |

The above is from the Ubuntu 12.04 system where there were no problems with the character set of text values in the tables. Notice that are some latin1 settings there, but that seems to be fine. The difference on the Debian 7.0 system was that these variable were set to latin1: character_set_client, character_set_connection, character_set_results. One way to change them is through the SET commands in MySQL console:

SET character_set_connection = utf8;

However, that will not persist the settings. Furthermore, it will not be enough to fix the tables. Instead, the config file /etc/mysql/my.cnf has to be changed with the following lines. (from this discussion).

collation-server = utf8_unicode_ci
init-connect='SET NAMES utf8'
character-set-server = utf8

Finally, after that is done, the MySQL server restarted, and the data with the special UTF8 characters have to be re-inserted. That is a bit of a pain, and I did not dig too far into how to resolve a problem with existing that. There is a discussion on how to alter the DB and tables here, but I suspect the data will still contain the wrong characters, so it will not be enough. Fundamentally, the byte representation in lation1 and utf8 for these letters are different, so that has the be replaced somehow, as far as I understand.

An alternative to all this is to get it right from the get-go. The MySQL documentation outlines how a new DB can be created with a specific character set. Again I’m not sure if that is enough, as the settings in the my.cnf file deal with the encoding of the client, connection, and result. There are probably several ways to solve the issue, though.

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Removing Lens Distortion in GIMP

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User yourgimptutor has a nice tutorial on how to remove lens barrel distortion using GIMP. The steps boil down to:

  1. Use the filter “Lens Distortion”: Filters -> Distorts -> Lens Distortion
    For a wide angled photo with the Canon EF-S 17-55 mm lens at 21.0 mm on a 50D body (1.6 crop) I found that adjusting the “Main” slider to +20 gave a good result.

  2. Use the Perspective Transform: Tools -> Transformation Tools -> Perspective
    The edges of the image can now be dragged out to the corners to fill the canvas size.

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chroot to ARM

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chroot allows you to “run a command or interactive shell with special root directory”, as the man page says. However, it is assumed that the second level root directory is built for the same CPU architecture. This causes a problem if you want to chroot into an ARM based image, for the Raspberry Pi, let’s say. qemu-arm-static, some “voodoo” and several tricks come to the rescue. The process is documented well at Sentry’s Tech Blog, and the original seems to be by Darrin Hodges.

After downloading and unzipping the image, it has to be mounted. There are a few ways to go about this, but I found the easiest was to use plain old mount with an offset. The typical RPi image file is a full disk image, as opposed to a single partition or ISO though. We are after the second partition, which in our case starts at sector 122880. (See this discussion for how to find the correct starting sector using fdisk).

mkdir /mnt/rpi
mount -o loop,offset=$(( 512 * 122880 )) 2014-01-07-wheezy-raspbian.img /mnt/rpi

Next we’ll copy a statically built QEMU binary for ARM to the mounted image. You might need to install QEMU on the host system first. Furthermore, we need to mount or bind the special system directories from the host to the chroot.

apt-get install qemu-user-static
cp /usr/bin/qemu-arm-static /mnt/rpi/usr/bin/

mount -o bind /dev /mnt/rpi/dev
mount -o bind /proc /mnt/rpi/proc
mount -o bind /sys /mnt/rpi/sys

Next comes the magic. This registers the ARM executable format with the QEMU static binary. Thus, the path to qemu-arm-static has to match where it is located on the host and slave systems (as far as I understand).

echo ':arm:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/bin/qemu-arm-static:' > /proc/sys/fs/binfmt_misc/register

Finally, it’s time for the moment of truth:

chroot /mnt/rpi

uname -a
Linux hrb 3.2.0-4-amd64 #1 SMP Debian 3.2.51-1 armv7l GNU/Linux

In some cases, the error “qemu: uncaught target signal 4 (Illegal instruction) – core dumped” occurs. User kinsa notes here that the lines of the file (i.e. on the slave, /mnt/rpi/etc/ has to be commented out (with a # in front).

Congratulations, you now have an ARM based chroot. What to do with it? Maybe install a few “missing” packages before copying over to one or more SD cards, set up the users, modify passwords, etc. Or take advantage of the CPU and memory of the host system or compile from source.

apt-get install htop tree ipython ipython3 gnuplot

As a final note, when done, you want to clean up the mount points.

umount /mnt/rpi/dev
umount /mnt/rpi/proc
umount /mnt/rpi/sys
umount /mnt/rpi

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Storage prices

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The new year has not seen major changes to the prices of spinning disks. However, on the SSD side, there are some interesting news, with Samsung really gearing up. Their 840 EVO and Pro series are now amongst the most affordable and reliable disks on the market.

The EVO series uses TLC memory, which stacks more bits per cell. This increases speed, but decreases reliability. The rule of thumb is 1000 writes for TLC memory, while MLC might be 10 times higher at 10k writes. It means that TLC disks will typically be for low to medium consumer use, while MLC is for higher pro use (as the series name also suggests). This is also reflected in Samsung’s warranty: Three years on the TLC disks, which is good, and an impressive five years on the MLC Pro disks. By comparison, Western Digital’s Red series has three years warranty, while the Green series has only two years.

Also notable is the fact that for the first time price per byte is lower for an SSD disk than a stack of 100 CD-Rs. That is of course because the 100 CD stack has stayed at about 30 Euros for the last six or more years. Never the less, it underlines the fact that 2014 will be the year when decent sized SSDs reach reasonable prices. Upgrading an older laptop with a 500 GB or 750 GB SSD is soon at a point where it makes sense, and will give good return on investment.

Media Type Product Capacity Price CHF Price Euros Euros / GB GBs / Euro
Harddisk Seagate Barracuda 4TB 4000 GB 164.00 134.43 0.03 29.76
Harddisk Western Digital Caviar Green 3TB 3000 GB 125.00 102.46 0.03 29.28
Harddisk Western Digital Caviar Green 4TB 4000 GB 169.00 138.52 0.03 28.88
Harddisk Western Digital Caviar Green 2TB 2000 GB 91.00 74.59 0.04 26.81
External 3.5 Western Digital My Book Essential Edition 4TB, USB3 4000 GB 183.00 150.00 0.04 26.67
Harddisk Western Digital Red 4TB 4000 GB 185.00 151.64 0.04 26.38
Harddisk Western Digital Red 3TB 3000 GB 139.00 113.93 0.04 26.33
External 3.5 Western Digital My Book Essential Edition 3TB, USB3 3000 GB 143.00 117.21 0.04 25.59
Harddisk Hitachi Deskstar 7K4000, 4TB 4000 GB 191.00 156.56 0.04 25.55
External 2.5 Western Digital Elements Portable 2TB, USB3 2000 GB 119.00 97.54 0.05 20.50
Harddisk Western Digital Caviar Black 4TB 4000 GB 260.00 213.11 0.05 18.77
Harddisk Western Digital Caviar Green 1TB 1000 GB 67.00 54.92 0.05 18.21
External 2.5 Western Digital My Passport 2TB, USB3 2000 GB 135.00 110.66 0.06 18.07
External 2.5 Western Digital Elements Portable 1TB, USB3 1000 GB 82.00 67.21 0.07 14.88
Blu-ray Verbatim BD-R SL 25 @ 50GB 1250 GB 238.00 195.08 0.16 6.41
DVD+R DL Verbatim 8x DVD+R DL 25 @ 8,5GB 213 GB 42.00 34.43 0.16 6.17
DVD-R Verbatim 16x DVD-R 100 @ 4,7GB 470 GB 96.00 78.69 0.17 5.97
DVD+R DL Verbatim 8x DVD+R DL 10 @ 8,5GB 85 GB 36.00 29.51 0.35 2.88
SSD Samsung SSD 840 EVO Basic, TLC, 750GB 750 GB 339.00 277.87 0.37 2.70
CD-R Verbatim CD-R 100 @ 700MB 70 GB 35.00 28.69 0.41 2.44
SSD Samsung SSD 840 EVO Basic, TLC, 1TB 1000 GB 555.00 454.92 0.45 2.20
SSD Crucial M500 SSD, MLC, 120GB 120 GB 78.00 63.93 0.53 1.88
SSD Samsung SSD 840 EVO Basic, TLC, 500GB 500 GB 329.00 269.67 0.54 1.85
SSD Sandisk Ultra Plus, MLC, 256GB 256 GB 172.00 140.98 0.55 1.82
SSD Samsung SSD 840 EVO Basic, TLC, 250GB 250 GB 171.00 140.16 0.56 1.78
USB Flash Sandisk Cruzer Flash Drive 32GB 32 GB 23.00 18.85 0.59 1.70
SSD Kingston HyperX 3K, MLC, 240GB 240 GB 186.00 152.46 0.64 1.57
SSD Samsung SSD 840 EVO Basic, TLC, 120GB 120 GB 99.00 81.15 0.68 1.48
SSD Samsung SSD 840 Pro Basic, MLC, 512GB 512 GB 439.00 359.84 0.70 1.42
SSD Samsung SSD 840 Pro Basic, MLC, 256GB 256 GB 229.00 187.70 0.73 1.36
SSD Kingston SSDNow KC300, MLC, 120GB 120 GB 111.00 90.98 0.76 1.32
SSD Corsair Force GT, MLC, 240GB 240 GB 222.00 181.97 0.76 1.32
SSD Sandisk Extreme, MLC, 480GB 480 GB 457.00 374.59 0.78 1.28
SSD Corsair Neutron, MLC, 128GB 128 GB 129.00 105.74 0.83 1.21
SDXC Sandisk Ultra SDXC, Class 10, 15/30MB/s, 64GB 64 GB 67.00 54.92 0.86 1.17
SSD Corsair Force GT, MLC, 120GB 120 GB 126.00 103.28 0.86 1.16
SSD Samsung SSD 840 Pro Basic, MLC, 128GB 128 GB 139.00 113.93 0.89 1.12
USB Flash Sandisk Cruzer Flash Drive 16GB 16 GB 18.00 14.75 0.92 1.08
SDHC Sandisk Ultra, Class 10, 15/30MB/s, 32GB 32 GB 37.00 30.33 0.95 1.06
USB Flash Sandisk Cruzer Extreme 64GB 64 GB 97.00 79.51 1.24 0.80
SDHC Sandisk Ultra, Class 10, 30MB/s, 16GB 16 GB 27.00 22.13 1.38 0.72
SDXC Sandisk Extreme SDXC, UHS-I, 80/60MB/s, 64GB 64 GB 119.00 97.54 1.52 0.66
SDHC Sandisk Ultra, Class 10, 30MB/s, 8GB 8 GB 16.00 13.11 1.64 0.61
SDHC Sandisk Extreme, Class 10, 30MB/s, 16GB 16 GB 35.00 28.69 1.79 0.56
USB Flash Sandisk Cruzer Flash Drive 8GB 8 GB 18.00 14.75 1.84 0.54
SDXC Sandisk Extreme Pro SDXC, UHS-I, 95/45MB/s, 64GB 64 GB 148.00 121.31 1.90 0.53
SDHC Sandisk Extreme Pro, Class 10, 90/95MB/s, 32GB 32 GB 78.00 63.93 2.00 0.50
Compact Flash SanDisk Ultra 200x, 16GB 16 GB 49.00 40.16 2.51 0.40
Compact Flash Sandisk Extreme 800x, 120MB/s, 128GB 128 GB 426.00 349.18 2.73 0.37
SDHC Sandisk Extreme Pro, Class UHS-I, 90/95MB/s, 8GB 8 GB 27.00 22.13 2.77 0.36
SDHC Sandisk Extreme Pro, Class UHS-I, 90/95MB/s, 16GB 16 GB 55.00 45.08 2.82 0.35
Compact Flash Sandisk Extreme 800x, 120MB/s, 64GB 64 GB 230.00 188.52 2.95 0.34
Compact Flash SanDisk Extreme 400x, 60MB/s, 32GB 32 GB 123.00 100.82 3.15 0.32
Compact Flash Sandisk Extreme Pro 160MB/s, 256GB 256 GB 1306.00 1070.49 4.18 0.24
Compact Flash Sandisk Extreme Pro 600x, 90MB/s, 16GB 16 GB 126.00 103.28 6.45 0.15

Exchange rate: 1 Euro = 1.220000 CHF.

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Fedora 20 released

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Fedora 20 was released a few days ago. J.A. Watson at ZDNet has a brief overview of the different desktops available, and concludes that for the most they run just fine on any hardware, including “sub-notebooks”. Furthermore, even though the “spin” of each desktop have specialised in their own applications, there are always plenty more to chose from in the main Fedora repositories.

The Anaconda installer was written back in release 18, and FedUp (FEDora UPgrader) is now the main system upgrade tool. It is not quite clear whether it is preferred to perform that on a running system though, as opposed to booting from an installer image.

Thus, the following links still apply, even for existing installations:

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Another assault on privacy by GCHQ

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Recently, it was revealed by IT Security Guru that the British intelligence agency GCHQ had demand a backdoor into the secure email service PrivateSky by CertiVox. At the end of 2012, GCHQ made the request, but CertiVox chose to close the service instead of betraying their customers. This is preceding the similar heavy-handed threats by NSA which caused US based Lavabit and Canadian based Silent Circle to shut down their secure email services.

It is clear then, that it is not possible to operate secure email or communication services within these countries. In that light, it’s interesting to see Swiss hosting companies picking up business. “Business for Switzerland’s 55 data centres is booming”, claims the article. It will be interesting to see how it plays out. Will they be pressured by US as was the case with the banks? Or will they also sell out, as was the case with the Swiss based Crypto AG and their machines?

As many have pointed out, the physical security of a data centre is often less of an issue than its network and system security. Furthermore, it’s a question of how it is used and what is offered. PrivateSky is for example still operational, but only for its owners. If somebody offered a secure communication service from within the Tor network, it would be both hard to detect, so it might fly under the radar for a while, and hard to take down if hosted in Switzerland. That’s a business idea right, up for grabs for anybody with a bit of spare time and money.

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VGA adapter for the Raspberry Pi

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Just tested a HDMI to VGA adapter for the RPi with my old CRT 1024×768 monitor. It works great! This was the HD2V04 HDMI to VGA + 3.5mm Audio Jack Converter Adapter Box from DealExtreme, at $21.70. The VGA port was a bit tight, so I had to make sure it was properly connected. Also, the monitor did not display anything before a cold restart of the Pi. It comes only with a USB power cable, to it means a wall wart or powered USB hub is required. (It should go without saying that you don’t want to power it off the Pi itself).

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DC-to-DC converters

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There are a number of different DC-to-DC converters out there, used to convert between different voltage levels. Ranging from the small but inefficient linear regulators to switched-mode converters like the buck converter that can achieve 95% or even higher efficiency. Among the switched-mode converters there are quite a few variations based on different but often similar circuit topologies: The buck converter is a step-down converter, and as the name suggest its output voltage will be reduced from its input. A boost (step-up) converter has similar design, but will do the opposite. A buck-boost converter combines the two so output voltage can be converted from both higher and lower input voltage. However, the traditional buck-boost converter inverts the polarity, so that the output voltage is of the opposite polarity than its input. A single-ended primary-inductor converter (SEPIC) (aka. buck-boost SEPIC) solves that problem, and delivers fixed non-inverted output throughout the range of its input voltage.

If this is all a bit confusing, have a look at Julian Ilett’s excellent YouTube videos and reviews: He covers the SEPIC buck boost converter, and shows how it seamlessly goes from 0.5 to 30 V out on a 9V battery. He shows how a 400W boost converter can drive a 100W LED pad, and he has a review of several different buck converters, in fact several reviews. He also has many interesting videos on driving different LED boards, including 50W and 30W RGB. You’ll really have to watch all his 140 videos!

When it comes to buying these, DealExtreme of course has a lot on offer, but here it seems like eBay has a bigger variety across its different sellers. I’ve already ordered this one, and expect to get more in the future. In particular, one of the variations on the ZXY6005 (D) power supply looks like a must-have in a hobby workshop.

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Trends: Snowden didn’t change public’s behaviour

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For all the NSA documents revealed by Snowden, and for all the news headlines stressing the gravity of the situation, it seems the general public has not changed their behaviour much. At least that would be the conclusion if looking at the worldwide trends of a few Google search terms: As can be seen in the first chart, the terms Snowden and NSA quickly rose to prominence when the story broke in the second half of 2013. However, interest quickly declined. If we look at the two next charts, comparing terms privacy, surveillance, encryption there seem to be no correlation with the former terms at all. Maybe there is an ever so faint increase in the term encryption, but nothing of significance.

The two last charts compare the terms encryption, surveillance in Germany. Here there is a small blip for the former term, while interest in the later, surveillance, seems to have increased significantly. This is possibly driven by the news stories there about NSA spying on Chancellor Angela Merkel.

These trends are rather disappointing to see. One would have hoped for at least a blip on the radar when it comes to public awareness of these issues. Instead, the distraction campaigns by most of the mainstream media seems to have been successful: The headlines have been focusing on Snowden, his girlfriend, his father, and whether he is a hero or traitor. Masking and excusing the abuse of power by NSA, GCHQ and the politicians who support these organizations have been successful. In fact, in Britain the story has taken the bizarre turn where the government is investigating The Guardian and editor Alan Rusbridger for publishing the leaked documents. What other clue do you need to see that the so called democracies and free countries of the West is nothing but a mirage for a powerful and abusive elite?

Swedish politician Rickard Falkvinge put it nicely in his post about the coming of the Swedish police-state:

A key difference between a functioning democracy and a police state is, that in a functioning democracy, the Police don’t get everything they point at.


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Fiber optics

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For a long time I’ve been plotting to make a fiber optic “star” ceiling, however I’ve been put off by the prohibitively expensive offers on fiber, at around one Euro per meter for the 1.0 mm thickness. Enter The Fiber Optic Store, specialising exactly in star ceilings, they have a wide range of filaments (i.e. single threads as opposed to cables) available at custom lengths. For their bigger quantities, 1.0 mm comes down to about $0.40 / meter. They also have some interesting combo-backs, and even a small sampling offer to get an idea of the sizes.

Furthermore, they have a large FAQ and guide section with a well of information and tips. And finally, for the DIY illuminator, they have a bright idea on how to attach the fiber treads to a single LED. As seen in the picture below, they are kept in place by heat shrink tubing.

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Soil Moisture Sensor

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Over at Andrew Frueh has an interesting article on a DIY soil moister sensor. It is simply two large nails with wires attached. By measuring the resistance of the soil between the nails, he gets a crude measurement of how wet the soil is. The more water, the lower resistance. He points to a few problems with this approach, including temperature affecting the resistance, as well as salinity and pH levels playing a role. Furthermore, electrolysis and corrosion is a problem over time. Frueh has improved on the basic circuit by using a H-bridge to alternate the direction of the current for the readings. That way, the nails last longer.

A different approach to measuring soil moisture, is to measure the dielectric constant. An example of such a sensor is the commercial product VG400 from Vegetronix. It sells for $37, so it doesn’t scale to use it for many plants the same way as two nails does. The method is interesting though, with more basic information in this University of Cambridge module.

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Building XBMC on the RPi

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Some notes on building XBMC from source on the Raspberry Pi: I started with the Raspbian 2013-09-25-wheezy image from here. After basic setup, I switched to CLI only, set the GPU memory to 16 MB, logged in over SSH, and started a screen session. A remote session is preferred, since there will be a lot of coping back and forth between the RPi and your desktop.

For the most, I followed these instructions, with a few modifications: First, the boot files to set GPU memory are not there in the Raspbian distribution I had installed. Instead, I used raspi-config to set the memory split. Secondly, the large one-liner apt-get install of all the dev packages (step 4 in the instructions) did not work very well. It gave dependency conflicts with the mesa packages. I found myself splitting up that line into many chunks, which then worked fine. Finally, a few packages were missing, and I had to run configure several times to figure that out. In the end, I also installed these:

apt-get install dh-autoreconf gawk gperf zip ccache

For a successful build, I had to modify the search path of a header file. There are a few ways to go about that, as discussed here. I used this solution:

sudo sed -i 's/#include "vchost_config.h"/#include "linux\/vchost_config.h"/' /usr/include/interface/vmcs_host/vcgencmd.h

That took me as far as a working XBMC setup, however videos are not playing. With MPlayer there is no problem, but XBMC just gives a black screen. I will have to investigate further.

There’s a similar set of instructions here.

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DealExtreme orders

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Various items ordered from DealExtreme.

GH-10W 10W 430lm 9-LED Red + Blue Light Plant Grow Light Module - Silver + White (7.5~8V) Jtron 0.36 8-Channel 5V Relay Module Shield for Arduino (Works with Official Arduino Boards) JY-MCU 5V 3V IIC UART SPI Level 4-Way Converter Module Adapter HSYY01 Water Pump Motor w/ Hose - White + Silver 20906 6mm Silicone Hose - Translucent White (5.44m-Length) Aquarium Fish Tank Flexible Silicone Air Line Tube - Black (18m) E5HT Aquarium Air Tube - Transparent Blue (10m) Aquarium Fish Tank Tubing Straight Connector T Splitter for 4mm Air Line (24 PCS) E5YK Aquarium Fish Tank 1-to-6 Air Splitter - White USB Powered Flexible Neck 10-LED White Light Lamp - Blue (27cm) 4-Port High Speed USB 2.0 Hub - Black (60cm-Cable Length) Mini USB 4 Ports Hub 4-Port USB 2.0 HUB w/ Independent Switch - Black 5V 2A Universal Power Adapter Charger - Black (AC 100~240V / EU Plug / 3.5 x 1.35mm) Raspberry PI Acrylic Case - Transparent Protective Neoprene Bag Case for DSLR Camera Lens - Black (Size XL) Protective Neoprene Bag Case for DSLR Camera Lens - Black (Size L) HSYY01 Water Pump Motor w/ Hose - White + Silver W3-9 Immersible Water Pump for Miniature Garden - Off-white SZF280 PVC Mini Water Pump Motor - Beige Miniisw SW-015 1.5W Polysilicon Solar Panel - Black Miniisw SW-008 0.8W Solar Powered Battery Panel Board - Black Protective Jellyfish Pattern Silicone Back Case for LG E960 Nexus 4 - Multicolored Replacement Sound and Music Activated Spectrum VU Meter EL Visualizer - Smile Face (4*AAA) 5.5 x 2.5mm Plug AC Power Adapter - Black (AC 100~240V / EU Plug / 135cm-Cable) 1.5 5.5 x 2.5mm Plug AC Power Adapter - Black (AC 100~240V / EU Plug / 135cm-Cable) HDMI Female to Micro HDMI Male Adapter 40-Compartment Free Combination Plastic Storage Box for Hardware Tools / Gadgets - Translucent White 24-Compartment Free Combination Plastic Storage Box for Hardware Tools / Gadgets Panel Mount 10A 250V Fuse Holder - Black (5-Pack) Optical Triple Triangular Glass Prism Spectrum - White Dupont 4-Pin Female to Female Extension Wire Cable for Arduino (40cm / 10-Piece Pack) Dupont 4-Pin Male to Female Extension Wire Cable for Arduino (40cm / 10-Piece Pack) Universal DIY Bakelite Plate PCB Board - Brown (2-Piece Pack) Universal Glass Fiber PCB Board for DIY Project - Brown Prototype Universal Printed Circuit Board Breadboard - Brown (5-Piece Pack) Nano V3.0 AVR ATmega328 P-20AU Module Board + USB Cable for Arduino Nylon PP6 DC 12V 50mA Tact Switch - Black (100-Piece Pack) 1N4007 1000V 1A Unilateral Rectifier Diodes Set - Black + Silver (50 PCS) LM7805L 5V Voltage Regulator ICs (10 PCS) 2.54mm 1x40 Pin Breakaway Straight Male Header (10-Piece Pack) GP LR44 A76 1.5V Cell Button Batteries 10-Pack 5 x 20mm Glass Tube Fuse Set - Silver (100 PCS) LCD Keypad Shield for Arduino Duemilanove & LCD 1602 (Works with Official Arduino Boards) Protective Plastic Case for 3.5 635~645nm 800~1000MCD 5mm LED - Red (100-Piece Pack) 510~520nm 800~1000MCD 5mm LED - Green (100-Piece Pack) S1306 8-in-1 Gradual ABS Lens Filters + Lens Mount + Ring Set for 77mm Lens Camera - Black Unique Black 4 Series Armed Notebook - Rambo Knife (60-Page) Convenient Rectangle Sticky Note Memo Pads (4 x 100 Pieces) Stainless Steel 1/4 C2-07 Creative Inflatable Shoe Boot Support Spreader - Milk White (Pair) Double-Sided Glass Fiber Prototyping PCB Universal Board (12-Piece Pack) Double-Sided Glass Fiber Prototyping PCB Universal Board (3 x 7 / 5-Piece Pack) Prototype Universal Printed Circuit Board Breadboard - Green + Silver 3mm & 5mm Light-emitting Diode - Green + Red + Yellow (100-Piece Pack) Breadboard Jumper Wires for Electronic DIY (65-Cable Pack) 4 Channel 5V High Level Trigger Relay Module for Arduino (Works with Official Arduino Boards) 2-Channel Relay Shield Module for Arduino (Works with Official Arduino Boards) AMS1117 5V Power Supply Module Emolux 62mm Multi-Coated UV Lens Filter - Black Sound and Music Activated Multi-Mode Flashling EL Hearts T-shirt - M (3*AAA) Silica Gel Reusable Moisture-Proof Bead Desiccant - Blue Male + Female DC Power Converter Connector Adapters w/ Terminal Blocks For CCTV Camera (Pair) Universal Heavy Duty 6F22 9V Battery DSTE NB-7L Replacement 7.4V 1200mAh Battery for Canon G10 / G11 - G12 / SX30 IS - Grey 1/4 Universal Aluminum Alloy Straight Flash Bracket for Camera - Black Universal Aluminum Alloy Tripod Bracket for Speedlight / Camera- Black Universal Handheld Jar Opener White Magic Beans with Assorted Messages (10-Pack Growing Plant) Genuine Acecamp 2429 20L Outdoor Water Resistant Dry Bag - Yellow 1000mA Car Cigarette Powered USB Adapter/Charger (DC 12V/24V) DIY 433MHz Wireless Receiving Module for Arduino (Works with Official Arduino Boards) 433MHz Wireless Transmitter Module Superregeneration for Arduino DIY 16-Key AD Keypad Module - Blue 4 x 4 Matrix Switch Module - Green ES-71 II Lens Hood for Canon Mini Prototype Printed Circuit Board Breadboard for Arduino (5 PCS) Ceramic Capacitor for DIY Electronic Circuit - Red (270-Piece Pack) Solderless Breadboard with 400 Tie-Point (White) USB to RS232 Serial Port Adapter (Transparent Green) FreArduino Soil Humidity Sensor for Arduino (Works with Official Arduino Boards) Double-Sided Glass Fiber Prototyping PCB Universal Board (3 x 7 / 5-Piece Pack) DIY HR-202 Humidity Detection Sensor Module - Blue Aluminum Alloy Straight Hot Shoe Flash Bracket for Camera - Black Flash Diffuser for Canon 580 EX / EX II / YongNuo YN560 / YN565 Speedlite (3 PCS) HT RJ45 RJ11 Cable Tester Stainless Steel 1/4 Mini USB 2.4GHz 150Mbps 802.11b/g/n WiFi Wireless Network Card Adapter - Black USB 2.0 2.4GHz 802.11b/g/n 150Mbps WiFi/WLAN Wireless Network Adapter Ultra-Mini Nano USB 2.0 802.11n 150Mbps Wifi/WLAN Wireless Network Adapter 6.3V 3300uf Aluminum Motherboard Capacitors (20-Piece Pack) DIY ZIF DIP IC Socket Set - Green (8 PCS) Solder Tip Refresher 3-Pin Triode Transistor for DIY Project - Black (20 x 10-Piece Pack) Aluminum Electrolytic Capacitor for DIY Project (120-Piece Pack) DisplayPort DP Male to HDMI Female Adapter Cable - Black (15CM) Gold Plated 1080i HDMI V1.3 M-M Connection Cable (1M-Length) 11x12 132-Panel Brain Teaser Magic IQ Ball Micro USB To HDMI MHL Adapter - Black Gold Plated HDMI Male to DVI 24+1 Female Adapter 62mm Digital Camera Lens Cover Digital Camera Lens Cover/Cap with Strap for Canon (62mm) 7.4V 1200mAh Lithium Polymer Lipo Battery Pack for Lama or 4-CH R/C Helicopters HC-SR04 Ultrasonic Sensor Distance Measuring Module 4 x AA Battery Case Holder (3-Pack) Stainless Steel Triple Razor Blade Set (4-Pack) USB 2.0 Smart ID Card Reader - Silver 30cm Breadboard Wires for Electronic DIY (40-Cable Pack) Cree XR-E Q2 Emitter with Star 3W LED Emitter on Star (Multicolored RGB)

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Adafruit order

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Some items ordered from Adafruit a while back.

  • BeagleBone Black
  • GPIO Extender Cable for Raspberry Pi – 12″ long
  • MCP23017 – i2c 16 input/output port expander
  • MCP23008 – i2c 8 input/output port expander
  • Plastic Water Solenoid Valve – 12V – 1/2″ Nominal
  • Liquid Flow Meter – Plastic 1/2″ NPT Threaded
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