【C51】Source code 1 -- LED pulse width modulation (PWM) dimming-EEWORLD

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　　I have recently become fascinated with single-chip microcomputers. With the basic knowledge I learned in college, I started to teach myself C51 single-chip microcomputer programming. I followed the tutorial to read the programming related to light-emitting diodes (LEDs), and wrote the following LED PWM dimming program as a summary.

　　Let’s talk about PWM dimming first. PWM stands for “Pulse Width Modulation”, which means changing the ratio of high and low levels within a fixed cycle to make the LED show different brightness levels.

　　The blogger compiled a relatively simple one: within the cycle of CYCLE pulses, the number of low-level pulses PWM_LOW increases from 0 to CYCLE, and the number of high-level pulses will of course decrease, so that the LED will show a "gradually bright" effect, and the same applies to "gradually dimming".

Attached is the source code: (I am a rookie, so there are inevitably some poorly written parts. It is only for backup purposes. Welcome to give me some advice, and please go away if you hate me...)

#include

#define CYCLE 300 // Define a cycle with 300 pulses

void Delay(unsigned int t);

sbit LED = P1^0;

void main(void)
{
unsigned int PWM_LOW; //Number of low levels
unsigned int PWM_HIGH; //Number of high levels

while (1) {

        for (PWM_LOW=0; PWM_LOW             LED = 0;
            Delay(PWM_LOW);
            LED = 1;
            Delay(CYCLE-PWM_LOW);
        }

        for (PWM_HIGH=0; PWM_HIGH             LED = 1;
            Delay(PWM_HIGH);
            LED = 0;
            Delay(CYCLE-PWM_HIGH);
        }
    }
}

void Delay(unsigned int t)
{
while (t--);
}

Keywords：C51 LED PWM Reference address：【C51】Source code 1 -- LED pulse width modulation (PWM) dimming

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