After rethinking this post a little, I feel a need to caveat things: In a previous post in this series I mentioned the possibility of using an open source System On A Chip because it would simplify the construction process somewhat. I've been doing some more research and I'm not certain that all SoC's (if that is the direction a project like this would go in) require system firmware of the sort we're about to discuss. The Broadcom BCM2835 mentioned earlier, for example, has firmware on board that is sufficient to initialize the hardware and then try to load the …
This brings us right along to designing and fabricating the circuit boards that our bright, shiny new open source chips will plug into. This level of complexity is probably one of the best understood parts of the development process. Arguably electrical engineering has been around since the discovery of electricity, because a circuit of some kind is required to guide an electrical current to do useful work. You could make the case that the wet string that Benjamin Franklin's kite was tied to was one of the first electrical conductors (because the Baghdad battery hypothesis has too many holes in …
If you've been following my website for a while you've no doubt read me yammer on again and again about 3D printers that can only use low-melting point plastics as feedstock for manufacture. Usually ABS or PLA plastic, because they're cheap and relatively easy to acquire. Joshua Pearce and his research team at Michigan Tech announced late last year that they've developed an open source metal deposition printer for fabricating tools and components for which plastic isn't appropriate. Their printer lays down thin layers of metal instead of plastic to build up much stronger objects. The total cost to construct …
This brings us along to designs that are rather common even though we don't normally think of them as either common or systems. By this, I refer to SoC's - Systems On A Chip. As the name implies, they are full (or nearly so) computers implemented as single mother-huge silicon chips (relatively speaking). On the die you'll find a CPU or microcontroller, supporting electronics for same, an MMU, and enough interfaces to do whatever you want, be it plug in a USB keyboard and mouse, an Ethernet adapter, or a simple USB-to-serial converter circuit. An excellent example of a SoC is …
Let's lay one thing out first: At some point you're going to have to start trusting your toolchain because it simply won't be possible to accomplish some of the necessary tasks yourself. The lowest possible level sseems as good a place as any to start. I mean silicon wafers, the basic component of integrated circuitry. Let's face it, nobody's in a position to turn ordinary sand and handfuls of trace elements into silicon wafers themselves. This is a very complex operation that you can't do in your basement these days. There are lots …
If you've been following my blog for a while you've no doubt picked up on my interest in 3D printing and the open source fabber called the RepRap. It seems that I'm not the only person who's been keeping a sharp eye on this particular technology. The Gada Prize (formerly the Kartik M. Gada Humanitarian Innovation Prize in Personal Manufacturing) has been announced to advance the state of the art in 3D printing and personal manufacture by putting up $20kus to the person or team whose project meets certain criteria by 31 December 2012. The prize appears to be aimed …
Wireless net.access is not yet ubiquitous, but it's pretty common and becoming moreso every day for a variety of reasons. Net.access is definitely in enough demand that a lot of places sell wireless access to whomever is willing to pay for it. If you're lucky, you'll get a good price on an hourly rate or a daypass, but if you're not you'll get reamed on the price of daily access (I remember one hotel I stayed at in Florida that demanded $30us per day for 802.11b access). This has angered some people to the point at which …
