TVout is a completely interrupt driven library that will output either NTSC or PAL composite.
Connect an RCA plug to the arduino according to the following schematic. A 75 OHM resistor may be needed between VID and GND on the RCA plug for a very small subset of TVs
SYNC is on OCR1A and AUDIO is on OCR2A
|m168,m328||B 1||D 7||B 3||NG,Decimila,UNO||9||7||11|
|m1280,m2560||B 5||A 7||B 4||Mega||11||29||10|
|m644,m1284p*||D 5||A 7||D 7||Sanguino||13||24||8|
|m32u4**||B 5||B 4||B 7||Leonardo||9||8||11|
|AT90USB1286||B 5||F 7||B 4||Teensy++||_||_||_|
*There are some timing issues with the m1284p, may be related to sanguino core.
**Support for the Arduino Leonardo has just recently been added.
There is a very complete and easy to navigate functional description found on the google code wiki