Hi guys,

I am new on arduino's, but old on PIC, and I found this very cool project on the internet:

he uses the ATMEGA8 directly.... with an 14.7456 MHz crystal... and arduino uses ATMEGA168 @ 16MHz, here is one source of my problems.

The other problem is the code being used on the arduino.

I did some modifications on his code, after looking a lot of datasheets... but I might be missing something here....

Code is on this URL:

My TV screen:

I wish my TV looked like this:

Btw I had do comment this part out of wiring.c

/* comment this
      // timer 0 prescale factor is 64 and the timer overflows at 256
      timer0_clock_cycles += 64UL * 256UL;
      while (timer0_clock_cycles > clockCyclesPerMicrosecond() * 1000UL) {
            timer0_clock_cycles -= clockCyclesPerMicrosecond() * 1000UL;

and the schematics on Gary´s website is wrong:

the pin that goes on the video out put is not the PB0/ICP... the right pin is the PD7/AIN1....

I used this to guide me thru the pins:

Hope someone could help me calculate this new values for the clocks...

Timing is really hard to deal when you don't have an oscilloscope...

Thanks in Advance,


Hi Antonio Santos,

Did you ended having success with this? This is one of the main reasons I'm starting with arduino.

Thanks, Nando

Hello Nando,

welcome aboard, I ended up side tracked by my work, and I did not do much after that. As you can see, there was a problem with the original Schematic, and you also have to make some modifications on the wiring.c file.

I would love make this project work... there are some projects with the MAX7456, but its a really expensive chip... I leave in brazil, so it costs about 50 dollars down here...

I think we need someone with knowledge in Video signals, and a osciloscope to help us on this project...

let me know of your findings....