Hi, I have a few questions regarding the OSD project found here:
**broken link removed**
I have had no luck getting this circuit to work, it displays a very very blurry representation, but the sync is all over the place, I thought about using a LM1881 chip, but it's more fun to try and get it working without.
I dont know if anyone is familiar with this, I have had no response from Bruno, it seems as though he has disappeared!
I have checked the oscillator and it appears to work, I can send video out, and you can just about make it out, but its very "jumpy", i've tried changing the clip level but to no avail, I have seen a project similar in AVR without a sync chip, so i'm guessing it is actually possible.
My video signal is a PAL - I, UK standard Composite input.
I have looked on Rickard's page:
**broken link removed**
And it states that the horizontal sync is 0v, yet according to the OSD page, it is triggered at 0.625v, is this correct?
There is no information about the Vertical Sync pulse as such on Rickard's page, but on the OSD page it states:
Yet it looks as thought it is only looking for one pulse duration in the C code provided on the OSD page.
Has anybody got this or something similar to work at all?
The code for the OSD is for Mikro C btw.
Any help would be appreciated.
Cheers
Wilksey
**broken link removed**
I have had no luck getting this circuit to work, it displays a very very blurry representation, but the sync is all over the place, I thought about using a LM1881 chip, but it's more fun to try and get it working without.
I dont know if anyone is familiar with this, I have had no response from Bruno, it seems as though he has disappeared!
I have checked the oscillator and it appears to work, I can send video out, and you can just about make it out, but its very "jumpy", i've tried changing the clip level but to no avail, I have seen a project similar in AVR without a sync chip, so i'm guessing it is actually possible.
My video signal is a PAL - I, UK standard Composite input.
I have looked on Rickard's page:
**broken link removed**
And it states that the horizontal sync is 0v, yet according to the OSD page, it is triggered at 0.625v, is this correct?
There is no information about the Vertical Sync pulse as such on Rickard's page, but on the OSD page it states:
Code:
We have to detect a 28 µs low level pulse, there are five of them in the vertical sync and none elsewhere.
Yet it looks as thought it is only looking for one pulse duration in the C code provided on the OSD page.
Has anybody got this or something similar to work at all?
The code for the OSD is for Mikro C btw.
Any help would be appreciated.
Cheers
Wilksey