User Manual

PoKeys user manual
45
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increased current demand - pins with such function embedded are marked as OC (open-collector) in
the pinout diagram. PoKeys PWM outputs can also be used to drive various R/C servo motors that
accept PWM signal with 50 Hz frequency (20 ms PWM period) and duty cycles between 5 and 10 % (1
to 2 ms).
PoKeys devices have an in-built PWM module that operates at a fixed clock frequency (25 MHz). Both
the PWM period and the PWM duty cycles must be expressed as number of module clock cycles (i.e.
20 ms PWM period equates to 0.020 x 25 000 000 = 500 000).
Figure 19: PWM output
PoKeys configuration software usage
PoKeys device’s PWM (pulse width modulation) module can be setup via Peripherals > PWM
outputs….
Figure 20: PWM outputs settings
In this window, user can enter PWM period and set PWM duties for each channel. Channels can be
independently enabled or disabled. After a change is made, user must click 'Set values' button or
check 'Send to device on change' checkbox. Left position of a slider means 0% and right position
100% respectively.