uMIDI
The swiss army knife for quick and easy developement of MIDI applications.
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PWM configuration and service functions. More...
Go to the source code of this file.
Macros | |
#define | PWM_MAX_DUTY ((1L << lookup_table_resolution) - 1) |
Maximum duty cycle of the PWM. More... | |
Functions | |
void | init_pwm_module (uint16_t(*conversion_function)(midi_value_t value)) |
Initializes the PWM. More... | |
void | set_pwm_duty_cycle (midi_value_t duty) |
Updates the PWM duty cycle. More... | |
PWM configuration and service functions.
#define PWM_MAX_DUTY ((1L << lookup_table_resolution) - 1) |
Maximum duty cycle of the PWM.
void init_pwm_module | ( | uint16_t(*)(midi_value_t value) | conversion_function | ) |
Initializes the PWM.
CPU timer 1 is clocked with the system clock (32 MHz) and the compare output A is set up to output a dual slope PWM. Additionally, a conversion function which is used in set_pwm_duty_cycle() to compute the duty cycle compare values is registered.
conversion_function | pointer to a function converting midi values to pwm compare register values |
void set_pwm_duty_cycle | ( | midi_value_t | duty | ) |
Updates the PWM duty cycle.
Computes a suitable duty cycle compare value and writes the PWM counter compare register. This procedure can be used to manually control the modulation.
duty | the desired duty cycle [0..MIDI_MAX_VALUE] |