Going back to electronic after a 20 years break

First part of the trigger management is partially done (only in time mode). The trigger level is shown as an horizontal blue line on the screen. The capture  is centered around the trigger point automatically.  Since we capture only one sample at a time, dealing with trigger is easy. We can just check the current sample/previous sample against the trigger value, it is quick and can be done on the fly, within the interrupt loop. It is way more tricky with the hardware based capture (more on that later). It can be noted that the "triggered" version is stable, while the non triggered version is phase shifting slowly. That is  due to the fact that we automatically center the trigger point in trigger mode. No trigger Trigger