This is a closed-caption decoder with serial output based on a PIC16C71
http://www.brouhaha.com/~eric/pic/caption.html
http://www.siriusmicro.com/projects/b2.pdf
Here is some code to allow you to use a serial terminal to read and write to the PIC's registers and EEPROM.
http://www.dougrice.plus.com/hp/freq/freq.htm
The Lego motor is controlled using a feed back mechanism to influence the pulse width modulation.
http://members.home.nl/b.vandam/lonely/pagina21.html
I2C driving of this RTC chip from a PIC microcontroller 16F877. Display via a graphical LCD. Character generation with an I2C EEPROM. Time and date are retained up to 10 years with a small 3V lithium battery.
http://www.techdesign.be/projects/007/007.htm
The DTMF detector is integrated in software. All the logic requested to receive and decode DTMF Commands over the phone line is integrated in the 16F877 chip.
http://www.geocities.com/constantinescuradu/content/dtmf.htm
closed caption decoder, video, DTMF, monitor tester, remote control etc
http://www.brouhaha.com/~eric/pic/
http://www.qsl.net/vu2upx/Projects/extralow.htm
http://www.qsl.net/vu2upx/Projects/frequency_cnt.htm
http://www.downtowninternet.com/elproducts/LLHfinal.PDF