Raspberry Pi, the famously cheap computer designed for teaching programming to kids inspired by the same sources that inspired another project of mine, Cymon’s Games. It's an ARM GNU/Linux box for $25!
Only it’s not really $25 and you didn’t believe that it was, did you? First of all that figure is outdated (they should really update their website’s banner text). Secondly, the assumption is that you’ve got most of the stuff that you need to get it running just lying around, so it ships with absolutely none of those “common” components. But what if (like me) you don’t have a room full of last seasons left overs that you can pick parts off of? Turns out you can actually get started with a minimum viable computer for less than $100 and it’ll be the cutest little desktop computer you’ve ever seen.
A few ground rules I set for myself when building this. First of all, all shipping will be calculated from the United States and vendors will be chosen accordingly. Secondly, I’m going to avoid where possible special deals like clearances and other “tricks” except one, which is the next rule. I’m going to assume you’ve got Amazon Prime to save shipping. If you’re a student it’s free. If you’re not then sign up for a free month and plan to buy a lot of stuff in that month. Finally, since readers of my other blog, Cymon's Games, are more into programming than electronics I’m going to avoid options that involve any wiring or soldering.
With that out of the way here’s the shopping list:
From Element 14:
Raspberry Pi – $35
5v Power Supply – $6.99
S/H – 8.03
From Amazon:
8GB SD Card – $6.99
Wireless mini keyboard/touchpad – $18.99
RCA Adapter – $2.44
12v power supply – $5.79
From Newegg (no shipping cost this item):
HiDef Car Monitor (at least 640×480 resolution) – $21.95
Grand total – $99.13
There we go, a minimum viable rPi computer for under $100. There’s no case, the keyboard is causing me trouble already, and you’ll need a wired connection, but it works and it’s really cool. If you don’t have a wired connection you’ll need to add $9.99 and get a wireless network adapter. Once you get that wireless adapter all your available USB ports will be filled up so you’re going to want to get a USB hub. I’m a fan of this 7 port one, if you don’t mind waiting for overseas shipping.
Another change you may want to make is to search second hand stores for a monitor and get a cheap HDMI to DVI cable then skip the 12v power supply, RCA adapter, and car monitor. The output would be less portable but more readable and if you can find one for less than $30.18 your alternate output will actually save you money.
As for the case I recommend taking the box your rPi came in, line it with the static bag, and cut holes for the connections. Sure, it’s ghetto but trust me, in a very short time you’ll out grow any case you buy and you’ll have a better idea real quick. That’s just the nature of this project.
But there you go, it is possible to get up and started with a Raspberry Pi for under $100, even if you don't have any of the necessary components on hand.