Conrad C-Control Pro Mega Series, Руководство пользователя

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199 C-Control Pro Mega Series
© 2008 Conrad Electronic
be entered into the measuring result. With a programmable prescaler the resolution of Timer_1 can
be set. Prescaler see
Table
.
Example: Activate Pulse Width Measurement (Project PMeasurement) 434 µs (100 x 4,34 µs, see Table
)
word PM_Value;
void Timer1_ISR(void)
{
int irqcnt;
PM_Value= Timer_T1GetPM ();
irqcnt=Irq_GetCount(INT_TIM1CAPT);
}
void main(void)
{
byte n;
// Define Interrupt Service Routine
Irq_SetVect(INT_TIM1CAPT,Timer1_ISR);
Timer_T0PWM ( 100 ,PS0_64); // Start Pulse Generator Timer 0
// Measurement starts here
// Output Timer0 OC0(PortB.3) connect to ICP(input capture pin, PortD.6)
PM_Value=0;
// Set mode to Pulse Width Measurement and determine prescaler
Timer_T1PM (0,PS_64);
while(PM_Value==0); // Measure Pulse Width or Period
Msg_WriteHex(PM_Value); // Output Measuring Value
}
For reason of better survey only a simplified version is shown here. Because of a collision on Pin
B.4 Timer_0 is used for pulse generation with Mega128. The entire program can be found in directory
PW_Measurement.
6.19.6 Timer Functions
In C-Control Pro Mega 32 there are two, in Mega128 three independent Timer available. These are
Timer_0 with 8 bit and Timer_1 with 16 bit (Timer_3 with 16 bit for
Mega128 only ). The timer have a
programmable prescaler (see
Table )
. After the defined period the timer will trigger an interrupt. An
interrupt routine can then be used to execute specific actions.
Timer_T0Time (8 Bit)
Example: Timer0: Switch output on with a delay of 6,94 ms (100x 69,44 µs, see Table )