Test your reaction speed. The system waits a random delay (1-5 seconds) after pressing "start", then lights an LED and starts a timer. The player presses "response" as quickly as possible; the timer stops and the reaction time is displayed (via serial or LEDs). Use P3.0 (RXD) and P3.1 (TXD) to send data to a PC terminal (9600 baud).
This project verifies your hardware and programmer work. Connect an LED with a 220Ω series resistor between P1.0 and GND. Code (C for SDCC/Keil): #include <at89x051.h> #include <delay.h> // simple delay function void delay_ms(unsigned int ms) unsigned int i, j; for(i = 0; i < ms; i++) for(j = 0; j < 1275; j++);
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. at89c2051 projects
while(1) if(button_pressed()) display_dice((random % 6) + 1); delay_ms(200);
Read a potentiometer using the on-chip comparator (P3.6 and P1.1) to adjust duty cycle. Test your reaction speed
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
Store code in EEPROM (external 24C02 via I2C emulation). Project 8: IR Remote Control Receiver (Sony SIRC or NEC) Difficulty: Advanced Components: TSOP38238 IR receiver, IR remote (TV/DVD remote) Use P3
So dig out that 8051 programmer, fire up Keil or SDCC, and start building. The world of classic embedded computing is waiting for you. Have you built an interesting project with the AT89C2051? Share it in the comments or on electronics forums – the retro computing community is always eager to see new ideas!