PIC_Hi-Tech_C_Mike_Pearces_I2C_routines
* Use 10 MHz crystal frequency.
* Use Timer0 for ten millisecond looptime.
* Blink "Alive" LED every two and a half seconds.
* Use pushbutton to exercise Screens utility.
A few years ago I became interested in first person shooter games and in particular how the world levels are created and rendered in real time. At the same time I found myself in between jobs and so I embarked on an effort to learn about 3D rendering with the goal of creating my own 3D rendering engine. Since I am a developer and not an artist I didn’t have the skills to create my own models, levels, and textures. So I decided to attempt to write a rendering engine that would render existing game levels. I mainly used information and articles I found on the web about Quake 2, Half Life, WAD and BSP files. In particular I found the Michael Abrash articles that he wrote for Dr. Dobbs magazine while working at Id to be very illuminating.
The unguided transmission of information using electromagnetic waves
at radio frequency (RF) is often referred to as wireless communications,
the first demonstration of which took place at the end of the 19th cen-
tury and is attributed to Hertz. The technology was, shortly thereafter,
commercialised by, amongst others, Marconi in one of the first wire-
less communication systems, i.e., wireless telegraphy. In the first half of
the 20th century the technology was developed further to enable more
than the mere transmission of Morse code. This first resulted in uni-
directional radio broadcasting and several years later also in television
broadcasting.
When 3GPP started standardizing the IMS a few years ago, most analysts expected the
number of IMS deploymentsto grow dramatically as soon the initial IMS specifications were
ready (3GPP Release 5 was functionallyfrozenin the first half of 2002and completedshortly
after that). While those predictions have proven to be too aggressive owing to a number of
upheavals hitting the ICT (Information and Communications Technologies) sector, we are
now seeing more and more commercial IMS-based service offerings in the market. At the
time of writing (May 2008), there are over 30 commercial IMS networks running live traffic,
addingup to over10million IMS users aroundthe world; the IMS is beingdeployedglobally.
In addition, there are plenty of ongoing market activities; it is estimated that over 130 IMS
contracts have been awarded to all IMS manufacturers. The number of IMS users will grow
substantially as these awarded contracts are launched commercially. At the same time, the
number of IMS users in presently deployed networks is steadily increasing as new services
are introduced and operators running these networks migrate their non-IMS users to their
IMS networks.
The continuing explosive growth in mobile communication is demanding more spectrally
efficient radio access technologies than the prevalent second generation (2G) systems such as
GSM to handle just the voice traffic. We are already witnessing high levels of mobile
penetration exceeding 70% in some countries. It is anticipated that by 2010 more than half of
all communications will be carried out by mobile cellular networks. On the other hand, the
information revolution and changing life habits are bringing the requirement of commu-
nicating on a multimedia level to the mobile environment. But the data handling capabilities
and flexibility of the 2G cellular systems are limited.
I can remember buying my first electronic calculator. I was teaching a graduate level statistics course and I
had to have a calculator with a square root function. Back in the late 1960s, that was a pretty high-end
requirement for a calculator. I managed to purchase one at the “educational discount price” of $149.95!
Now, I look down at my desk at an ATmega2560 that is half the size for less than a quarter of the cost and
think of all the possibilities built into that piece of hardware. I am amazed by what has happened to
everything from toasters to car engines. Who-da-thunk-it 40 years ago?
This Section covers the design of power transformers used in buck-derived topologies: forward converter, bridge, half-bridge, and full-wave centertap. Flyback transformers (actually coupled inductors) are covered in a later Section. For more specialized applications, the principles discussed herein will generally apply.
