Page 190 - ARM Based Microcontroller Projects Using MBED

176 8. INTERMEDIATE LEVEL PROJECTS

FIG. 8.36 Typical display from the program.

BEGIN
Display heading
J = 10,000
DO 10 times
Start Timer
DO J times
ENDDO
Stop Timer
Display J and Elapsed time
J = 2 * J
ENDDO
END

FIG. 8.37 Program PDL.

TABLE 8.3 Timer Functions
Timer Function Description
stop Stop the timer
start Start the timer
reset Reset timer to 0
read Read the elapsed time in seconds
read_ms Read the elapsed time in milliseconds
read_us Read the elapsed time in microseconds

Table 8.3 presents the various Timer functions available with Mbed. The following steps
show how to measure the elapsed time in part of a program:

• Define a Timer variable, for example, Timer tim
• Start the Timer, for example, tim.start()
• Program code whose duration will be measured
• Stop the Timer, for example, tim.stop()
• Read the elapsed time in seconds, for example, tim.read()
• Reset the Timer to 0, for example, tim.reset()
The elapsed time can be read in seconds, milliseconds, or in microseconds. It is important
that the Timer should be reset to 0 before it is used successively.