Page 300 - ARM Based Microcontroller Projects Using MBED
P. 300
286 10. USING LIQUID CRYSTAL DISPLAYS (LCDs)
FIG. 10.4 Program listing.
10.3 PROJECT 2—EXTERNAL INTERRUPT-DRIVEN EVENT
COUNTER
10.3.1 Description
In this project a character LCD is connected to the development board as in the previous
project. A GPIO pin is configured as an external interrupt pin and this pin is used to simulate
the occurrence of external events. An event is said to occur when this pin goes from HIGH to
LOW and generates an external interrupt. The program counts and displays the event count
on the LCD in the following format:
Count¼nnn
10.3.2 Aim
The aim of this project is to show how text and numeric data can be displayed on the LCD.
Additionally, the project shows how an external interrupt pin can be used in a project.
