[robotpic]

e dung pic 18f4331 e . mọi người xem giúp nhé


T PWM:

công thuc tính: pr2= TPWM/(4*Tosc*TMR2prescale)-1

fosc = 20 Mhz=20,000,000, Tosc=1/20,000,000=0.00,000,025 s

Fpwm = 10 KHz=10,000Hz,Tpwm=1/10000=0.0001s

TMRprescaler = 4

==> PTPER =124


Tpwm= (duty)*Tosc*tmr2 prescale

vd: 100% Tpwm=0.0001s ===> duty=500
50% Tpwm=0.00005s ===> duty=250


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T POWER PWM // ho 18f4331 pic nay co 2 che do ===> 2 cach tinh khac nhau

O che do Free run:

PTPER = (fosc*Tpwm)/(4*PTMR prescaler) - 1

fcy = 20 Mhz=20,000,000, Fpwm = 10 KHz=10,000Hz, PTMRprescaler = 4

==> PTPER =124


Tpwm= (duty)*Tosc*tmr2 prescale

vd: 100% Tpwm=0.0001s ===> duty=500
50% Tpwm=0.00005s ===> duty=250