Only change the software, without adding hardware

CodePudding user response:

In the software instead, don't add hardware, c52 can't change the interrupt level trigger mode to high level trigger,

CodePudding user response:

Only after edge-triggered inspection level high and low, but need to consider the jitter problem

CodePudding user response:

89 c52 external interrupt support only low-level and down along the trigger mode, only change the software, under the condition of not adding hardware, personally, I think there is no way if real-time demand is not high, through the way of polling reading IO status (of course, you can open a timer interrupt, judging regularly read IO port state),