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Raspberry Pi

Powering from an old LCD Monitor
Truth be told, I didn't think much of the Raspberry Pi at first in large part because hooking them up involved a lot of cables and hardware. However, I recently discovered a way to hack an old LCD monitor for use as the Raspberry Pi's display and power source. Since the monitor I was using required a USB input in order for the outputs to be powered, I initially used a printer cable to connect the two ports. Being too cheap to waste a printer cable when I knew all that was happening was a simple connection between two points on a circuit board, I opened up the monitor and soldered a small piece of wire between the two 5V pins of the USB input and one of the USB outputs. Works great.


Here are some pics of the finished product:

 

Tools and Parts

Modifications to Make Using raspi-config
  • Expand Filesystem
  • Internationalisation Options >> Change Keyboard Layout
    1. Select the Generic 105-key (Intl) PC model
    2. Select Other layout
    3. Select English (US) - right below English (UK)
    4. Select English (US) - at the very top)
    5. On the rest of the following screens select the default options.
  • Advanced Options >> Audio >> Force 3.5mm ('headphone') jack

USB Conflict Fix
If you're having trouble getting your USB keyboard and WiFi dongle to work together, try the following fix suggested by Ludovic Rousseau:

Add dwc_otg.speed=1 to the /boot/cmdline.txt file, as follows:

dwc_otg.lpm_enable=0 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200
dwc_otg.speed=1 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4
elevator=deadline rootwait


Setting up the Pi
  1. Go to Adafruit to learn how to set it up.
  2. Make sure to set the keyboard to US (otherwise keymapping is very annoying)
  3. To set the Pi to use DVI: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=63&t=39858
  4. Finding your Pi's IP so you can remote into it: http://trevorappleton.blogspot.com/2013/03/remotely-find-raspberry-pi-ip-address.html
    1. In the Target box type: 192.168.1.0/24
    2. Select Profile: Ping scan
    3. Click on: Scan
    4. The Cirago Wifi/Bluetooth dongle appears as: XAVi Technologies
  5. Fix for the following error: GDBus.Error:org.freedesktop.PolicyKit1.Error.Failed: An authentication agent already exists for the given subject
    • Go into "Preferences->Desktop Session Settings" and un-check "PolicyKit Authentication Agent"

Installing the Arduino IDE

To install the latest version of the Arduino IDE, it looks as though you first have to upgrade Raspbian and then follow the these instructions. If you are using the Kano image, you may have to install java first with: apt-get install oracle-java8-jdk. Unfortunately, the drivers for the ESP8266 are not available for the ARM architecture.


Sharing a Mac's WiFi

  • Go to System Preferences -> Network and change the IP address for your ethernet connection to Using DHCP with Manual Address and copy and paste the ip address for your wifi connection.
  • Go to System Preferences -> Sharing and share your Internece from your Wifi connection with the ethernet connection.


Dynamic DNS

I purchased a domain name from Google Domains and set up ddclient without Google Domains support.


Hosting Multiple Websites

https://www.debian-administration.org/article/412/Hosting_multiple_websites_with_Apache2


Remote Connection

Use XRDP.


Protoboard

Deal Extreme sells a nice prototyping board for the B+: DIY Prototyping Expansion Board for Raspberry PI B+


Frustrations

  • Not good for robots (only 2 pwm pins and no adc).
  • Doesn't run Minecraft or OpenSCAD among other things.


Solution

Use cell phone as a hotspot for connecting to the Pi. (Need to test this)


Motion Activated Security Camera

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