Before we start...
The main goal of this project was to check possibilities of use the Atmel AVR microcontroler in
tasks rather not usual for 8-bit microcontroler.
There are many ideas I wanted to test with this project. Some of them are:
Video signal generation (tested, working)
Capacitor measurement (tested, working)
Audio noise cancellation (working on it)
Infra-red RC5 decoding (not tested by now)
Although I've used to use Microchip PIC16 family of chip, this time I decided to use Atmel AVR microcontroler.
There are few reasons of this decision:
AVR is faster than PIC16. Most of the instructions take only one cycle. That gives
up to 16 MIPS on 16 MHz AVR. PIC16 used with this frequency got only 4 MIPS.
AVR's got multiplication unit. Well, at least some of them ;)
I can use my favourite GCC compiler on AVR. In fact, this is the only 8-bit platform that allows
me to use it;
I've used the Atmel ATMega8 chip overclocked to 17.734475 MHz, which is four times the frequency of PAL colour
signal 4.4297125 MHz. For digital-analog conversion the R2R ladder was used;
The PCB was made at home, using photochemical method
Devboard - ATMEL zoomed