If you're a fan of technology, chances are you've retired a few gadgets over the years and they are sitting in a box in your closet. Today's the day to dig out your leftovers and start thinking about what you can do to let them live and breathe again.
What do you do if you have some left over computer parts, a Raspberry Pi (RPi) and a bored child? And some spare time of course...
I decided to build a 'portable' Raspberry Pi computer, so he can start to learn programming using Scratch and play Minecraft obviously :).
I had an old screen lying around and was thinking to combine that with a RPi so he could use it to learn all about the great Raspberry. The main condition was that it has to be 'portable' - he must be able to carry it around the house and plug it in anywhere he like. To achieve that, I planned to have the RPi attached to the back of the monitor and also use the power from the monitor itself to avoid a multitude of cables he has to plugin all the time.
What do you need?
I used the following items to build this portable Pi. Depending on what type of LCD Monitor you are using, your list of ingredients might vary.
|Raspberry Pi B+||1||¥3078|
|Raspberry Pi B+ Case, Black||1||¥863|
|Step Down Regulated Power Supply (Variable Output)||1||¥110|
|8GB Micro SD Card Class 10||1||¥1533|
|Old LCD Monitor||1||¥0|
|Electrical wires (thin) powering the RPi||~15cm 2x||¥0|
|HDMI Cable female-female||1||¥0|
|VGA Cable male-male||1||¥0|
|HDMI to VGA converter||1||¥420|
The total cost is about ¥6435 (In US Dollar this is roughly about $50).
How did I do it?
First step was to check the inside of the monitor to see if there was sufficient space available, and in what way the electronic boards are assembled.
As there was more than enough room, I drilled some holes; one for the small wires powering the RPi. I made sure the hole would be under the case so the wire wouldn't be visible. To attach the RPi to the back of the monitor I needed two holes, one hole I drilled (fitting the RPi), the other hole was already there, which was the hole for an optional VESA bracket.
I removed the electronics boards temporarily to see if power could be tapped somewhere from them. I found a 12V connection and soldered wires from that point to connect to the input/mains of the Step Down Power Supply. Before continuing, I did a quick test to see the voltage output with a digital multimeter. The Step Down Power Supply gave a nice 5.33V :)
Subsequently, I soldered the small wires (positive and negative) to the output of the Step Down Power Supply. But first pushed them through the hole I drilled earlier. The wires I used were actually Dupont cables female connectors at then other end that fit nicely on the RPi GPIO connector. Connected the red wire to GPIO Pin 2 (5V) and the black wire to GPIO Pin 4 (GND).
Since the RPi Case had two holes for attaching it to something, I decided to use these holes to guide through a small cable tie. It turned out to be a good strong fit, that is also easy to remove if needed.
After everything was connected, I quickly checked if the RPi would power up. Before that, a few adjustments to the /boot/config.txt of the RPi had to be made due to the use of the HDMI/VGA adapter. Some of these adapters don't work straight away with your RPi. The following additions are added to the /boot/config.txt file:
- hdmi_force_unplug=1This is to force the RPi to output at the HDMI port and not on the composite video output.
- hdmi_safe=1This is to force the RPi to output at a low resolution.
- config_hdmi_boost=4You can boost the HDMI signal by adding this line and change the value from 0 - 7.
A quick reboot after saving these settings, made the output on the VGA port work perfectly!
I completed all the regular steps of installing Raspbian and made it connect to our Home WiFi network using a USB WiFi Adapter so I could get latest Debian updates at any time. Also I wanted to set the RPi UI to Japanese. For that I took the following steps:
Run the following command:
sudo dpkg-reconfigure locales
In the next screen, I enabled the following locales
- en_GB.UTF-8 UTF-8
- ja_JP.EUC-JP EUC-JP
- ja_JP.UTF-8 UTF-8
and set ja_JP.UTF-8 UTF-8 to be the default.
Lastly some fonts need to be downloaded in order for the Japanese characters to be displayed correctly:
apt-get install ttf-kochi-gothic xfonts-intl-japaneseapt-get install xfonts-intl-japanese-big xfonts-kanamesudo reboot