Most computer science students get to learn high-level programming languages and application development but they don’t really understand computers. The fun of controlling the real world with a real computer is never exposed to them.
A normal computer lacks the capability to communicate with the real world through real interfaces.
With a normal computer that has a monitor, keyboard, mouse, printer and modem connected, hardly anything can be done, except the intended use. Of course, the printer port on a PC can be used to interface with the real world but that will be very clumsy and cumbersome—not to talk of the non-availability of an easy programming environment for that.
The Raspberry Pi is a pleasant exodus from that monotonous computing world. You can hold this palm-size computer in your hand and at the same time interface with the real world with its 26 input/output (I/O) pins. With a Raspberry Pi in hand, robotics is no more a fancy imaginary world of big and serious people but a real and authentic one.
You can get this computer for a small amount of money. In the UK, the Raspberry Pi Model-A costs $25, while the price of Model-B is $35, plus local taxes and shipping/handling fees. In India, at many hobby outlets, it is available for only Rs 2600. In fact, the latest B Model with 512MB RAM is no less than a Celeron computer of yesteryear, yet with a whole lot of imagination and possibilities to tap.
Model-A and Model-B
The first model of Raspberry Pi that appeared was Model-A, which had only one USB port and no Ethernet socket. Later, Model-B came into market with two USB ports, Ethernet socket and 256MB RAM. The latest one has as much as 512MB RAM. It is built around a BCM2835 Broadcom processor. It consumes 5V electricity at 1A current. As power consumption is less, there is no heat dissipation and no clumsy heat-sink is required. The operating system is based on the light-weight ARMv6 instruction set that a typical Broadcom processor understands—all open source and based on Linux variety.
Wiring it up
Connect the peripherals as shown in Fig. 1.
Video cable connection. Unfortunately, the normal PC monitor—a VGA monitor—does not support connectivity with Raspberry Pi. The Raspberry Pi team, in fact, has thought beyond this and provided the latest and oldest connectivity for video.