At89c2051 Projects (2026)

Add a push button to increment the count manually. Project 3: Digital Dice with 7 LEDs Difficulty: Intermediate Components: 7 LEDs (arranged like a dice face), 7x 220Ω resistors, 1 push button

Since the AT89C2051 lacks hardware PWM, we generate it using Timer0 interrupt. unsigned int duty = 1500; // 1.5ms center void timer0_isr() interrupt 1 static bit state = 0; if(state == 0) P1_0 = 1; TH0 = 0xFC; // 1ms? Actually calculate for 1.5ms TL0 = 0x18; state = 1; else P1_0 = 0; TH0 = 0xFE; // 20ms - duty TL0 = 0x??; state = 0; at89c2051 projects

void main() while(1) P1_0 = 0; // LED ON (assuming common cathode) delay_ms(500); P1_0 = 1; // LED OFF delay_ms(500); Add a push button to increment the count manually

Servos require a 50Hz PWM signal with pulse widths from 1ms to 2ms. Actually calculate for 1

void send_string(char *s) while(*s) SBUF = *s++; while(!TI); TI = 0;

Once you master these , you can move to its bigger brother – the AT89S52 (8KB flash, 3 timers, more I/O) – or even to ARM, but the logical foundation remains the same.

I/O pin control, timing loops. Project 2: 7-Segment Display Counter (0-9) Difficulty: Beginner Components: Common cathode 7-segment display, 8x 220Ω resistors Circuit: Connect segments a-g and DP of the display to P1.0 – P1.7 via 220Ω resistors. Common cathode to GND. Code snippet (lookup table): unsigned char segment[] = 0xC0, 0xF9, 0xA4, 0xB0, 0x99, 0x92, 0x82, 0xF8, 0x80, 0x90; // Common anode // For common cathode, invert the bits: ~segment[i] & 0x7F void main() unsigned char count = 0; while(1) P1 = ~segment[count]; // active low for common cathode? // Adjust based on your display type. delay_ms(1000); count++; if(count > 9) count = 0;