UM0224 Datasheet, PDF (24/34 Pages) STMicroelectronics – STR75x Demonstration Software

Running the demonstrations
STR75x demonstration software
2.4.5
Period measurement
This menu allows you to measure the period of an external input signal. The STR750 timers
can be used in PWMI (PWM input) mode to measure the frequency and the duty cycle of an
input signal in a range which depends on the TIM1 clock: in our case the range is from 458
Hz to 10 kHz. You have to connect the signal to be measured to the TIM1_TI2/P0.31 pin.
If the input signal is in the specified range, the following message is displayed on the LCD:
Duty Cycle: xx%
Freq: xxxxx Hz
If the signal is under the low limit of the range, the following message is displayed on the
LCD:
Out of range!!
Freq < 458 Hz
If the signal is over the high limit of the range, the following message is displayed on the
LCD:
Out of range!!
Freq > 10 kHz
If there is no signal connected to the TIM1_TI2/P0.31 pin, the following message is
displayed on the LCD:
!!no signal!!
Press UP/DOWN
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