Hi,

A budget solution:

Use the Hardware PWM in the PIC together with a filter (2 caps and 2 resistors) to get an adjustable DC level by changing the duty cycle of teh HPWM. Feed this in to an OP if you need more current. This is excactly the same as having a 255 step DA converting chip by only adding a few cents of components. If you dont have a HPWM, it is possible to make a SW one but pick a PIC that has.

Buy a LM1881 (sync separator chip) for a dollar or two, connect the video source from the receiver to it. Then connect the V-sync signal from this chip to your PIC.

Let the software check the V-sync signal period to make sure it is correct, if it is not correct, adjust the duty cycle and voila ,hopefully :-)


Then you have a kind of PLL, since you are locking the HPWM dutycycle to the v-sync signal from this chip. The LM1881 has been around for a long time so it is nothing special.


Total cost less then 10 USD with PIC and all.

/me