About the raspberry Pi

About the Raspberry Pi The resulting Raspberry Pi server should only cost about $2 of electricity per year to run (in the U.S.), plus under $2 for the Insteon PLM in the case discussed below. Compare that to some typical PCs that use 50 to 150 watts (that's about $50 to $150 per year if left on all the time). The Pi will quickly pay for itself if you avoid turning on that old PC or leaving your main computer on all the time.

The Pi may not be as cheap as it first appears because it doesn't come with everything a typical computer comes with. A lot of people have spare parts that can be used with the Pi, but if you need to buy a lot of peripheral parts your price will be higher. Here's what you need:

• A "power supply". The Pi is powered from a micro USB port, and most people will have a spare USB charger that plugs into the wall capable of powering the Pi. The catch is that you need more milliamps than a typical USB wall charger if you're going to run much of anything off the Pi's USB ports. If all you need to do is plug an Insteon PLM into the Pi's USB, then you'll be fine with a typical 500ma wall charger because the PLM powers itself.
• An ethernet cable that will reach the Pi or a wifi USB dongle if you Pi doesn't have built in WiFi (newer models do). If you add a dongle you might need a larger power supply. You could potentially skip the internet connection if you don't want to remotely control the Pi, but that means you need to plug in a keyboard, monitor, and maybe a mouse.
• A real-time clock module, if necessary. The Pi keeps its time by using the internet, but if you need it to operate without an internet connection, you'll need to add a real-time, battery powered clock module.
• A powered USB hub if you run out of USB ports. Since a powered USB hub provides its own power, you won't need a bigger power supply for the Pi to run USB-powered devices.
• An SD card. A basic MH installation only uses about 1.6GB so even a 2GB SD card can be used, but 4gb is preferable. You can currently buy a 32GB for $22, but that's overkill unless you want to put that in some other device and take the old low GB card from the other device and use it for the Pi. You can also find SD cards for sale with the Raspberry Pi operating system already installed. That might be a good option for some as getting the operating system onto the SD card is perhaps one of the harder steps in the Pi setup process, but it shouldn't be very hard for most people and the pre-installed SD card will cost you more.
• An SD card writer. Unless you bought an SD card with the Pi OS already installed on it, you need a slot on one of your computers that you can insert an SD card into and write the Pi OS to your SD card. Many laptops, newer computers, some tablets, and even most smart phones come with a slot for an SD card, although things keep changing and a micro SD card slot may be more typical on the newest devices. You might even be able to find some way to make your smart phone write the Pi OS to a micro SD card and use an adapter to make the micro SD card SD card sized. Otherwise, you can buy a relatively cheap ($20 or less?) SD card reader/writer box you can connect to your computer using USB. Good boxes will support 7 or more different memory card formats and have lots of different slots in them.
• A video screen with HDMI input. You can use your TV if you want to (I did). The video is only necessary for initial Pi setup. After setup, you can set up methods to remotely control the Pi from your computer.
• Expert users: It's also possible to avoid connecting video if you create a file called ssh in the boot partition of the SD card. This enables SSH (discussed later) which you can use to set up the Pi remotely after it boots. You will also need to figure out what IP address the Pi was assigned by looking at what devices are connected to your DHCP server.
• A USB keyboard. Also only necessary during initial setup. A USB mouse is not necessary but may help.
• A case. Yes, the Pi does not come with a case. A case should run $10 to $20, or you can make your own.

A good general setup guide for the Pi can be found here. I'll be giving similar instructions, but I'm not going to include as many details or screenshots.

Since I wasn't sure if Raspberry Pi would work out or not, I didn't order a case for it. Some people use the box it comes in as its case, but I didn't want to cut holes in that in case I wanted to return it. So I put a twist tie through one of the holes in the Pi and hung it up from the draw string of some blinds. You could also set it on something non-conductive and not prone to static. The pink anti-static coated bags are perfect, but the metallic grey bag the Pi comes in is not ideal because it's slightly conductive. I've seen people holding the Pi in their palm and I've read that it's not easy to damage a fully assembled circuit board like the Pi with static electricity, but I've also read you can do invisible damage with static that causes parts to fail sooner than they otherwise would, so I was as careful as possible. To that end, I recommend at least touching the metal frame of a grounded piece of electronics before handling the Pi and hold it from the edges of its board when possible. Don't touch its electronics or put undue pressure on its connectors.