TV output with seperate cog

Daniel M.

I have been playing around with a propeller demo board for the last few days(especially the video outputs). I have been using the TV_Terminal object; but when I go to have another cog handle the data being sent to that object, the processor seems to lock up. The example from the manual involving toggling the two lights works perfectly, yet implementing the same code here does not. Any help would be much appreciated!
daniel

Mike Green

What do you mean by "another cog handle the data being sent to that object"?

The TV.spin object has its own cog to generate the video, but the routines to put the characters into the screen buffer use whatever cog called them. If you loaded yet another cog to do some data manipulation, you might:

1) Not have allocated enough space for the new cog's stack
2) Be trying to change the same variables from two cogs at once. This is true if you're writing data to the screen buffer from two cogs.
If that's what you want to do, you will need to use a semaphore to negotiate the use of the screen. Look at the examples in the manual
under the LOCKxxx statements.

Whenever you have some kind of "odd" problem or something that doesn't make sense, you will need to supply more information to get help.
There are lots of potential reasons for problems to occur and the details matter. Please include programs as attachments unless they are very short.