PWM Pseudo Code

40,000 ticks per mS assumes a 40Mhz clock, we will use SysClk/32 for PWM
Set 200 Hz frequency so 5mS for the Motor H bridge period
Set 20 mS for the Servo period
Set 200 Hz frequency so 5mS for the Motor Shooter period

Use PWM module 0 for this demo and program it for up/down counting


InitPWM()
Use volatile to avoid over-optimization
Start by enabling the clock to the PWM Module (PWM0)

Enable the clock to Port B,E  
Select the PWM clock as System Clock/32
Make sure that the PWM module clock has gotten going
Disable the PWM0 and PWM1 while initializing

Program generator0 A to go to 0 at rising compare A, 1 on falling compare A  

Program generator0 B to go to 0 at rising compare B, 1 on falling compare B  

PWM0 program generator1 A to go to 0 at rising compare A, 1 on falling compare A  

PWM0 program generator2 A to go to 0 at rising compare A, 1 on falling compare A  

	
Set the PWM period. Since we are counting both up & down, we initialize
The load register to 1/2 the desired total period

Initialize three generators¡¯ periods(Generator 0,1,2) separately 

Set the initial Duty cycle on A to 50% by programming the compare value to 1/2 the period to count up (or down) for all three generators separately 

Set the initial Duty cycle on Generator 0, B to 25% by programming the compare value to 1/4 the period  

Set changes to the PWM output Enables to be locally syncronized to a zero count

Enable the PWM outputs

Configure the Port B pins to be PWM outputs
Start by selecting the alternate function for PB4, 6 & 7 and PE4


Choose to map PWM to those pins, this is a mux value of 4 that we want to use for specifying the function on bits 4, 6 & 7
Enable pins 4,6 & 7 on Port B and Port E 4 for digital I/O
Make pins 4,6 & 7 on Port B and Port E 4 into outputs
Set the up/down count mode and enable the PWM generator


Set0_DC_L()/Set0_DC_R()/Set0_DC_Shooter()/Set0_DC_Servo()/

When duty cycle is 0
Set specific pin to be low and disable the pin

Set100_DC_L()/Set100_DC_R()/Set100_DC_Shooter()/Set100_DC_Servo()/

When duty cycle is 100
Set compare value to the full load value

SetDutyCycle_X( uint8_t value )   //Here X can be L, R, Shooter, Servo

If value = 0
Set 0_DC_X()

If value = 100
Set100_DC_X()

Else
Set compare period to (value/100)*full load period value