Daddy's amateur MCU learning: Using Digital tubes and LEDs to achieve traffic lights (first edition)

/*

* Sidewalk traffic light program: led2 (red light), led3 (yellow light), and led4 (green light)
* The red light is 30 seconds, the green light is 3 seconds, the green light is 15 seconds, and the countdown is
The lighting time is displayed on the digital tube.
* The crystal oscillator is 11.0592 MHz. LEDs and digital tubes are controlled by 38 decoders and t0 is interrupted.

* Program idea: As the decoder can only output one low level at a time, the digital tube and led must be lit in dynamic scanning mode, with the interruption interval of 1 ms.

* Countdown of the Light-on time, 60 seconds for the red light, 20 seconds for the green light, and 3 seconds for the yellow light. The sequence is: red-green-Yellow-red cycle. Therefore, every 1000 interruptions occur, and the number is decreased.

*/

# Include <reg52.h>
Unsigned char K; // 1 s timing flag
Unsigned char smg_buffer [2] = {0xff, 0xff}; // Digital Display Buffer

Unsigned char red, yellow, green;
Sbit led2_red = P0 ^ 0; // red light Interface
Sbit led3_yellow = P0 ^ 1; // yellow light Interface
Sbit led4_green = P0 ^ 2; // green light Interface

// The third-eight decoder controls the digital tube, with one digit: 01000, ten digits: 01001
Sbit addr0 = p1 ^ 0;
Sbit addr1 = p1 ^ 1;
Sbit addr2 = p1 ^ 2;
Sbit addr3 = p1 ^ 3;
Sbit enled1 = p1 ^ 4;

// Digital tube 0 ~ 9
Unsigned char code SMG [10] =
{0xc0, 0xf9, 0xa4, 0xb0, 0x99,0x92,0x82, 0xf8, 0x80, 0x90 };

// Digital Display
Void smg_display ()
{
Unsigned char Shijian; // lighting time
Static unsigned char color = 0; // color: 0: Red, 1: yellow, 2: Green, starts from red by default
If (Shijian <= 1) // starts to change when the last to one second,
{
Switch (color)
{
Case 0: color = 2; Shijian = 10; Red = 1; break; // The red light turns green after 60 seconds. The red light marks the position 1.
Case 1: color = 0; Shijian = 3; yellow = 1; break; // yellow light for 3 seconds, yellow to red after the end, yellow to 1
Case 2: color = 1; Shijian = 20; Green = 1; break; //; the green light turns yellow after 20 seconds. The green light marks the position 1.
Default: break;
}
}
Else Shijian --; // decrease the time
If (Shijian = 1) // time changes until 1
{
Red = 0; yellow = 0; Green = 0; // the position of each flag is 0.
}
Smg_buffer [0] = SMG [Shijian % 10]; // digital display, single-digit
Smg_buffer [1] = SMG [Shijian/10% 10]; // ten
}

// Timer Configuration
Void config_interruptime0 ()
{
Tmod = tmod & 0xf0;
Tmod = tmod | 0x01;
Th0 = 0xfc;
Tl0 = 0x66;
Ea = 1;
Et0 = 1;
Tr0 = 1;
}

Void Init ()
{
Addr3 = 1;
Enled1 = 0;
}
Int main ()
{
Init ();
Config_interruptime0 ();
While (1)
{
If (k = 1) // check whether the 1-second scheduled time has been reached
{
K = 0; // K Reset
Smg_display (); // refresh the display
}
}
Return 0;
}

Void interruptime0 () interrupt 1
{
Static unsigned int CNT = 0;
Static unsigned int I = 0;
Th0 = 0xfc; // initial value of 1 ms
Tl0 = 0x66;
CNT ++;

Switch (I)
{
Case 0: p0 = 0xff; addr0 = 0; addr1 = 0; addr2 = 0; I ++; p0 = smg_buffer [0]; break; // single-digit Digital Display
Case 1: p0 = 0xff; addr0 = 1; addr1 = 0; addr2 = 0; I ++; p0 = smg_buffer [1]; break; // display 10 digits
Case 2: p0 = 0xff; addr0 = 0; addr1 = 1; addr2 = 1; I = 0; // LED Display
If (Red = 1)
{
Led2_red = 0;
}
If (yellow = 1)
{
Led3_yellow = 0;
}
If (Green = 1)
{
Led4_green = 0;
}
Break;
}
If (CNT = 1000)
{
K = 1; // when the 1 second is reached, k = 1
CNT = 0;
}
}

Daddy's amateur MCU learning: Using Digital tubes and LEDs to achieve traffic lights (first edition)