Posts from 2012-11

Setup an NTP Server in Mac OS X 10.8

The How-To: Setup an NTP Server in Mac OS X still works for OS X 10.8. Here are the steps once again:

Here is how to set up an NTP Server in Mac OS X

Open the "Date & Time" system preferences. Disable "Set date & time automatically".

Edit the file /etc/ntp.conf...

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WiFi-Stick Edimax EW-7811Un for the RaspberryPi (with Arch Linux ARM)

This is how it shows up in the kernel log / dmesg on Ubuntu:

[712886.216957] usb 1-1.2: new high-speed USB device number 5 using dwc_otg
[712886.318980] usb 1-1.2: New USB device found, idVendor=7392, idProduct=7811
[712886.319014] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[712886.319034] usb 1-1.2: Product: 802.11n WLAN Adapter
[712886.319051] usb...

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Raspberry Pi and Arduino

It can be a fruitful thing to connect an Arduino to your Raspberry Pi. Here are some thoughts and options:

À la mode Shield

Simple USB-Serial Connection

You can also simply use a USB port on your Raspberry Pi to connect your Arduino.

Here is a...

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Ethernet of Raspberry Pi Running ALARM Died Once

Two or three weeks ago my Arch Linux ARM based Raspberry Pi died. At least it wasn't accessible via Ethernet anymore. Here are the syslog details:

Nov  4 01:45:01 alarmpi -- MARK --
Nov  4...

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Rotating Videos on the Command Line

Rotating videos is a task that's not that uncommon if you're filming with your camera in upright position. You can easily do this with ffmpeg:

ffmpeg -i -vf "transpose=1"

The command line tool ffmpeg is available for all major operating systems (I'm using it on Mac OS...

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Oerlikon Leybold IONIVAC ITR 90 Vacuum Gauge

The ITR 90 transmits the measured values via RS232. The protocol is given in the detailed manual.


I wrote a software to read out the vacuum gauge with you computer:


RS232 Connector

Mapping of the RS232 port to the DSUB15 connector on ITR90:

Connector DSUB15 Meaning RS232
Pin 13 TxD (Transmit Data)
Pin 14 RxD (Receive...

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VScom USB-4COM-M – A 4-Port USB-to-Serial Adapter

The VScom USB-4COM-M is a 4-port USB-to-Serial adapter. It has a sturdy metal case and is made for industrial use. It is based on FTDI's FT4232H.

Ubuntu 12.04 dmesg output

Seems to work without drivers on Ubuntu:

[17724.148265] usb 2-6: new high-speed USB device number 2 using ehci_hcd
[17724.303330] USB Serial...

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Installing `pip` on Windows

I found this solution on StackOverflow which worked for me on Windows 7:

  • Install Python (currently I'd use Python 2.7).
  • Add C:\Python27\Scripts to your %PATH% environment variable in order to be able to use Python and the the programs without naming the full path.
    Read more about this here
  • Install...

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Add a Directory to your %PATH% in Windows as an Underprivileged User

To temporarily add C:\Python34\Scripts to your %PATH% in a command line prompt in Windows, run

set PATH=C:\Python34\Scripts;%PATH%



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Elegant Way to Display Bytes as Hex Values in Python

Elegant code to print a hex string in python:

toHex = lambda x: "".join("{:02X}".format(ord(c)) for c in x)

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Agilent XGS-600 Vacuum Gauge Controller

Product Description

The XGS-600 Gauge Controller accepts any of three different kinds of gauge cards which, between them, operate all Agilent vacuum gauges. Choose from

  • Convection gauges such as thermocouple or ConvecTorr
  • Hot filament ion gauges
  • Inverted magnetron (cold cathode or Penning) gauges

Up to six cards can be installed in the XGS-600 Controller, in...

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