Connect an LED with a 220Ω series resistor between P1.0 and GND.
To start building these AT89C2051 projects, you need:
Difficulty: ★★★★☆
Concept: Use a TSOP1738 IR receiver module connected to an external interrupt pin. Decode the signal from a standard TV remote (NEC protocol).
Output: Display the decoded Address and Command on two 7-segment displays or an LCD. at89c2051 projects
Why this is hard: IR protocols require microsecond precision. You will need to disable interrupts during the measurement of pulse widths and use software delays calibrated to your crystal frequency.
Project application: Create a custom IR remote for your home automation system, using an AT89C2051 as the receiver. Connect an LED with a 220Ω series resistor between P1
Learning outcome: Creative use of comparator, time-based analog measurement.
AT89C2051
┌───┐ ┌───┐
RST|1 ○ 20|VCC (+5V)
P3.0|2 19|P1.7
P3.1|3 18|P1.6
XTAL2|4 17|P1.5
XTAL1|5 16|P1.4
P3.2|6 15|P1.3
P3.3|7 14|P1.2
P3.4|8 13|P1.1
P3.5|9 12|P1.0
GND|10 11|P3.7
└───┘ └───┘
Once this circuit is built, you can program the chip using a suitable programmer and Keil uVision or SDCC compiler. Breadboard Components: