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This article mainly shows you "how to improve the performance of single-chip microcomputer buttons", the content is easy to understand, clear, hope to help you solve your doubts, the following let the editor lead you to study and learn "how to improve the performance of single-chip microcomputer buttons" this article.

Our common button scanning procedures are as follows:

Unsinged char KeyScan (void) {unsigned char KeyValue=0; if (KEY_IO! = 0xFF) / / detected a key press {DelayNms (20); / / delay of 20ms (seriously affecting the running efficiency of the single-chip microcomputer) if (KEY_IO! = 0xFF) / / confirm that the key is pressed {switch (KEY_IO) {case 0xFE: KeyValue=1;break; case 0xFD: KeyValue=2;break; default: KeyValue=0;break;} return KeyValue;}

In reality, the forum to see the following code, we might as well do so, no delay, the running efficiency is greatly improved! The real-time performance of single-chip microcomputer is significantly improved!

/ / read key uchar read_key () {static int Key_on_off = 0; / / key self-locking variable uchar num, temp; num = P2; num & = 0xf0; / / set the lower four digits to 0 if (num! = 0xf0) {if (Key_on_off = = 0) {Key_on_off = 1; switch (num) {/ / return the key code case 0xe0: temp = 1; break; case 0xd0: temp = 2; break Case 0xb0: temp = 3; break; case 0x70: temp = 4; break;} else Key_on_off = 0; return temp;} these are all the contents of this article entitled "how to improve the keystroke performance of single Chip Microcomputer". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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