TRENDnet TK-207K KVM Mounting Bracket

By ctherouxNo Comments
TRENDnet TK-207K KVM Mounting Bracket

A “TRENDnet TK-207K KVM Mounting Bracket” is now available. More details at TRENDnet TK-207K KVM Mounting Bracket.

3D Printing, object

How about a Raspberry PI 2 as a firewall?

By ctherouxNo Comments

Raspberry PI 2

A Raspberry PI 2 performs as expected exceptionally well as a firewall. The download throughput achieved was 33 Mbits/sec under the same test conditions as the previous test (see Can A Raspberry PI Be Used As A Firewall? for more details). The CPU usage was about 5% during the download test. The CPU usage was around 2% while performing the upload test.

Networking, Raspberry PI, Unix, Wheezy

Can a Raspberry PI be used as a firewall?

By ctheroux1 Comment

Raspberry PI Model B

Can a Raspberry PI be used as a firewall? This question comes back often. Well, I have tested it. The test conditions are:

  • a Raspberry PI Model B (256MB of RAM)
  • a USB to Ethernet wired interface. 100 Mbits/sec.
  • Raspian (May 2015) as the OS.
  • My Internet connection is 30 Mbits/sec. for download, 10 Mbits/sec. for the upload speed.
  • www.speedtest.net has been used to carry the speed tests.

The answer is NO. I got a download speed of about 30 MBits/sec. Using a PC as the firewall with a similar setup, I achieved around 32 MBits/sec. While doing the download test, the CPU usage was 100% while being 20% for the upload test. Memory was not an issue with about 165 MB free.

I would certainly use this Raspberry PI as a firewall for an Internet connection of 20-20 Mbits/sec. or less.

A similar test will soon be performed using a Raspberry PI 2.

Networking, Raspberry PI, Wheezy

Cable Hanger for Doors

By ctherouxNo Comments
Cable Hanger

A “Cable Hanger for Doors” is now available. More details at Cable Hanger for Doors.

3D Printing, object

STM32 Minimum System Development Board

By ctherouxNo Comments

Upload code to a STM32 Minimum System Development Board

This post describes how to upload code to a STM32 Minimum System Development Board that can be bought from Ali Express or eBay for around $4.00 US. You will be able to compile and upload a led blinking program to the board at the end of this guide. This guide is using Arduino_STM32 by Roger Clark.
You will need:

  1. to download Roger Clark’s Arduino IDE STM32 board support files. It can be downloaded from this link.
  2. to download the latest Arduino IDE. It can be downloaded from this link.
  3. a USB to TTL Serial Cable that uses 3.3V signal level such as link or any equivalent cable.

The setup steps are:

  1. First, install the Arduino IDE following the provided instructions.
  2. Install Arduino SAM Boards (32 bits ARM Cortex-M3) using the Arduino IDE option Tools -> Board -> Boards Manager.
  3. Locate the hardware folder within the Arduino IDE installation folder.
  4. Un-archive the STM32 support files in the hardware directory found in the Arduino IDE installation folder.  Rename the top folder Arduino_STM32-master to Arduino_STM32.  If you restart the Arduino IDE, you will find in the Tools -> Board option a new set of boards including the STM32F103C Series.
  5. Connect the TTL Serial Cable ground pin to one of the ground pins of the board labeled G.   It is the black wire on the picture below. The TTL Serial Cable shall be disconnected from the PC at this stage.
  6. Connect the TTL Serial Cable 5V to the pin labeled 5V on the board.  It is the red wire on the picture below.  A 3.3V supply can also be used.  In this case, connect the 3.3V supply to a pin labeled 3.3 on the board.
  7. Connect the TTL Serial Cable RX pin to the board A9 pin. It is the white wire on the picture below.
  8. Connect the TTL Serial Cable TX pin to the board A10 pin. It is the green wire on the picture below.
  9. Set the jumpers.  Boot0 shall be set to 1 (HIGH) and Boot1 to 0 (LOW).  The Boot1 jumper is right beside the reset switch.
  10. Plug the TTL Serial Cable to the PC.  A red led should light up on the board indicating that it is powered.

The board setup looks like this using an Adafruit 954 TTL Serial Cable.

Upload code to a STM32 Minimum System Development Board

STM32 Minimum System Development Board Wiring

In the Arduino IDE:

  1. Create a new sketch (File -> New).
  2. Copy the code below.  It will make the onboard led blink.
  3. Select the board  Generic STM32F103C Series from the Tools -> Board option.
  4. Select STM32F103C8 (20k Ram, 64 k Flash) from Tools -> Variant option.
  5. Select Serial from the Tools -> Upload method option.
  6. Select the port of the TTL Serial Cable from the Tools -> Port option.
  7. Verify the sketch (Sketch -> Verify/Compile).
  8. Hit the reset button on the board and wait 4 seconds.  If you do not wait enough, you will get a “Failed to init device.” message.
  9. Upload the sketch to the board (File -> Upload).  You will get a bunch of messages.  The last line will be “Starting execution at address 0x08000000… done.”.
  10. The green led will now blink.

If you reset the board or unplug it, your program will not run unless you set both Boot0 and Boot1 jumpers to 0 (LOW).

The test sketch is:


void setup() {
pinMode(PC13, OUTPUT);
}


void loop() {
digitalWrite(PC13, HIGH);
delay(100);
digitalWrite(PC13, LOW);
delay(100);
}

Arduino, STM32

Change the Ubuntu login screen background?

By ctheroux1 Comment

Changing the login screen background is easy but not obvious. The image file you want to use as the login screen background must have a read access for everyone. Open the image with the Image viewer installed by default. Select the option Set as Wallpaper from the Image menu.

The Appearance option of the Settings will only let you change the desktop background.

Ubuntu, Ubuntu 12.04, Ubuntu 14.04, Ubuntu 15.04

Make an Apache2 SSL server more secure

By ctherouxNo Comments

These easy steps will improve significantly the security of your Apache2 SSL server. Edit your /etc/apache2/mods-enabled/ssl.conf file and replace the SSLProtocol, SSLCipherSuite and SSLHonorCipherOrder parameters with the following values.

SSLCipherSuite ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA

SSLHonorCipherOrder on

SSLProtocol all -SSLv2 -SSLv3

apache, Debian, Linux, Ubuntu, Unix

Raspberry Pi Model B+ Drilling And Mounting Plates

By ctherouxNo Comments
Raspberry Pi B Plus view 2

“Raspberry Pi Model B+ Drilling And Mounting Plates” are now available. More details at Raspberry Pi Model B+ Drilling And Mounting Plates.

3D Printing, object

Raspberry Pi Model B Drilling And Mounting Plates

By ctherouxNo Comments
Raspberry Pi B view 1

“Raspberry Pi Model B Drilling And Mounting Plates” are now available. More details at Raspberry Pi Model B Drilling And Mounting Plates.

3D Printing, object

Arduino Mega / Mega 2560 / Due Drilling And Mounting Plates

By ctherouxNo Comments
Arduino Mega view 2

“Arduino Mega / Mega 2560 / Due Drilling And Mounting Plates ” are now available. More details at Arduino Mega / Mega 2560 / Due Drilling And Mounting Plates.

3D Printing, object

Arduino UNO / Duemilanove / Diecimila / Leonardo Drilling And Mounting Plates

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Arduino UNO / Duemilanove / Diecimila / Leonardo / NG / Extreme Drilling And Mounting Plates

“Arduino UNO / Duemilanove / Diecimila / Leonardo / NG / Extreme Drilling And Mounting Plates” are now available. More details at Arduino UNO / Duemilanove / Diecimila / Leonardo / NG / Extreme Drilling And Mounting Plates.

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Beaglebone Black Drilling And Mounting Plates

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Beaglebone Black view 2

“Beaglebone Black Drilling And Mounting Plates” are now available. More details at Beaglebone Black Drilling And Mounting Plates.

3D Printing, object

pcDuino V2 Board Drilling And Mounting Plates

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pcDuino V2 view 1

“pcDuino V2 Board Drilling And Mounting Plates” are now available. More details at pcDuino V2 Board Drilling And Mounting Plates.

3D Printing, object

Freescale FRDM-KL25Z Board Drilling And Mounting Plates

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Freescale KL25Z view 2

“Freescale FRDM-KL25Z Board Drilling And Mounting Plates” are now available. More details at Freescale FRDM-KL25Z Board Drilling And Mounting Plates.

3D Printing, object

Solarbotics L298 Compact Motor Driver Drilling and Mounting Plates

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Solarbotics L298 Compact Motor Driver view1

“Solarbotics L298 Compact Motor Driver Drilling and Mounting Plates” are now available. More details at Solarbotics L298 Compact Motor Driver Drilling and Mounting Plates.

3D Printing, object

Keyes Mosfet Power Control Board Mounting And Drilling Plates

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Keyes Mosfet Power Control view1

“Keyes Mosfet Power Control Board Mounting And Drilling Plates” are now available. More details at Keyes Mosfet Power Control Board Mounting And Drilling Plates.

3D Printing, object

ALTERA Cyclone II FPGA Development Board Mounting and Drilling Plates

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Altera Cyclone II Dev Board view1

“ALTERA Cyclone II FPGA Development Board Mounting and Drilling Plates” are now available. More details at ALTERA Cyclone II FPGA Development Board Mounting and Drilling Plates.

3D Printing, object

PN532 Breakout Board Mounting Plate And Drilling Guide

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pn532 view1

“PN532 Breakout Board Mounting Plate And Drilling Guide” are now available. More details at PN532 Breakout Board Mounting Plate And Drilling Guide.

3D Printing, object

SparkFun RFID USB Reader mounting plate and drilling guide

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view1

“SparkFun RFID USB Reader mounting plate and drilling guide” are now available. More details at SparkFun RFID USB Reader mounting plate and drilling guide.

3D Printing, object

SMD Probe Case

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view3

“SMD Probe Case” is now available. More details at SMD Probe Case.

3D Printing, object
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