Raspberry Pi Adventures
I’ve had my raspberry pi for a few months now and thought it was about time that I shared my experiences. Out of the box I had a few teething problems. This post covers those issues and how to resolve them.
When I placed my order I didn’t add a power supply. Instead I was using an old HTC phone charger. The charger must supply at least 700mA at 5V and use a Micro USB connector (not to be confused with Mini USB). The charger unit will have the rating written on it if you’re not sure. In my case it supplies 1A at 5V, more than enough.
SD Card Preparation
Stupidly, I didn’t order an SD Card when I purchased the Pi. Instead, I had to run to the shops where I picked up a SanDisk Class 10 8GB SD Card. To be safe, I would go with one of the ones listed here http://www.raspberry-pi.co.uk/2012/06/07/compatible-sd-cards/
So you’ve bought your card. The next step is to install the operating system. As of writing, the recommended OS to use is the Raspbian “wheezy” image. Once you’ve downloaded and extracted the .img file, the next step is to copy the files to the SD Card. For reasons that I don’t fully understand, you can’t simply copy the files to the SD Card. If you’re running linux you should use a utility like dd or usb-imagewriter. Full instructions here http://elinux.org/RPi_Easy_SD_Card_Setup
Although I hadn’t much experience with dd before I was fairly confident I was using the correct syntax. dd returns some information to the command line so you know when it’s completed. Run the ‘sync’ command to ensure all files have been written before you eject the card. Put the card back into the pi and insert the power lead to turn it on. If it works, you’ll see all the lights flashing and you should see the splash screen.
If, like me, this whole business was a failure, then only the power led will be lit and nothing will be on the screen. Plan B was to use a program called usb-imagewriter. To install on Ubunutu, use ‘apt-get install usb-imagewriter’. This program has a GUI, unlike dd, and it seems to work. I inserted the SD and…. Voila!
Note: It may seem odd but there is no on/off button on the pi. Once the power is plugged in, it should boot.
Once the Pi has finished booting, you’ll be at a command prompt. You can login using root and it doesn’t require a password. I can’t really remember my first boot now but I think that you are presented with a configuration utility with a rudimentary, blue GUI called ‘raspi-config’. Don’t worry if you don’t see the config utility. You can start it by running ‘raspi-config’.
There are a few things you may want to do before you start the graphical desktop.
- Firstly, you may want to expand the root filesystem. This allows the linux partition to use the entirity of the card. I recommend doing this unless you have plans for creating additional partitions later.
- I noticed that the entire screen was not in use, despite the fact I was using HDMI. Disabling overscan removed the black border.
- You can enable ssh from this GUI. ssh is useful for remotely connecting to the Pi. If you are thinking of running the pi as a server then this is recommended (assuming you have another computer).
- Helpfully, raspi-config can update itself if you have an internet connection but you can do this later if it’s not working.
You can stay on the command line if you like. Raspbian uses the very lightweight LXDE, which I also happen to use on my laptop. Enter the command startx to start LXDE.
There is a list of tested peripherals at http://elinux.org/RPi_VerifiedPeripherals but a basic keyboard and mouse should work straight away. I took the gamble and bought a cheap keyboard and mouse from Maplin and they worked almost perfectly.
If, like me, you have more than two peripherals then you will need a USB hub. Again, I would make sure that it’s a compatible device before you take the plunge. The same applies to wifi dongles, although I have my raspberry pi connected using ethernet.
I have had intermittent problems with powering the keyboard and sometimes it seems not to work. Taking it out and plugging it back in resolves it for me. I think this has been fixed in the latest version of Raspbian but I can’t be sure.