If you are interested in the programming side you can start with something like Lego MINDSTORMS. If you are more interested in the electronics side you may want to check out some of the kits on Parallax and The Robot Store. You will find a mix of languages and platforms so really pick your favorite … Read more
Some USB hubs have the ability to turn power off to its downstream devices. “Is it possible to power up ports on a USB hub from Ubuntu?” https://askubuntu.com/questions/149242/is-it-possible-to-power-up-ports-on-a-usb-hub-from-ubuntu Which points to some c source for hub-ctrl.c See: http://www.gniibe.org/development/ac-power-control-by-USB-hub/index I tested this on Ubuntu with a Dream-Cheeky USB LED unit, and it did seem to turn … Read more
Personally, I’d recommend an ARM Cortex-M3 based microcontroller. The higher-power ARM cores are extremely popular, and these low-power versions could very well take off in a space that is still littered with proprietary 8/16-bit cores. Here is a recent article on the subject: The ARM Cortex-M3 and the convergence of the MCU market. The Arduino … Read more
Today AVR and PIC are probably the most common microcontrollers among hobbyists. Both have a very wide range of device variants and both can be used to achieve similar results. For a beginner I would suggest AVR due to various reasons: AVR family (tiny, mega) is coherent and easy to understand. The architecture is powerful … Read more
When structures are defined, the compiler is allowed to add paddings (spaces without actual data) so that members fall in address boundaries that are easier to access for the CPU. For example, on a 32-bit CPU, 32-bit members should start at addresses that are multiple of 4 bytes in order to be efficiently accessed (read … Read more
Look here for a good wiki book. I had some coursework I wrote when I was teaching Electronic Eng, but I couldn’t find it around. When I was teaching, most of the students were happy to use the schematic capture tools in the Xilinx Foundation package. They’ve moved onto ISE and WebPACK now. You can … Read more
A homebrew Forth runtime can be implemented in very little memory indeed. I know someone who made one on a Cosmac in the 1970s. The core runtime was just 30 bytes.
Bits per second is straightforward. It is exactly what it sounds like. If I have 1000 bits and am sending them at 1000 bps, it will take exactly one second to transmit them. Baud is symbols per second. If these symbols — the indivisible elements of your data encoding — are not bits, the baud … Read more
Most of what you’re talking about are embedded systems where C is a luxury that may not be available. The software often isn’t separate programs running under an OS like you’d have on a desktop or phone, especially if the chip the designers chose to use is described as a “microcontroller”. Most of the time … Read more