PWM Motor Control Library
  mikroC PRO for dsPIC30/33 and PIC24 Libraries > Hardware Libraries > 
  

PWM Motor Control Library

The PWM Motor Control module is available with a number of dsPIC30/33 MCUs. The mikroC PRO for dsPIC30/33 and PIC24 provides a library which simplifies using the PWM Motor Control module.

  Important :

Library Routines

PWMx_Mc_Init

Prototype

(I) unsigned int PWMx_Mc_Init(unsigned long freq_hz, unsigned int pair_output_mode, unsigned int enable_channel, unsigned int clock_prescale_output_postscale);

(II) unsigned int PWM1_MC_Init(unsigned long freq_hz, unsigned int pair_output_mode, unsigned int enable_output_x, unsigned int clock_prescale_output_postscale);

(III) unsigned int PWM_MC_Init(unsigned long freq_hz, unsigned primary, unsigned clock_prescale);
Description

Initializes the Motor Control PWM module with duty ratio 0.
The function calculates timer period, writes it to the MCU's PTPER register and returns it as the function result.
Parameters

(I)

  • freq_hz: PWM frequency in Hz (refer to device datasheet for correct values in respect with Fosc).
  • pair_output_mode: output mode for output pin pairs. Valid values are given in the table below :
    Value Description
    _PWM_MC_CH1_PAIR_INDEPENDENT_MODE PWM1L and PWM1H will in independent mode.
    _PWM_MC_CH1_PAIR_COMPLEMENTARY_MODE PWM1L and PWM1H will in complementary mode.
    _PWM_MC_CH2_PAIR_INDEPENDENT_MODE PWM2L and PWM2H will in independent mode.
    _PWM_MC_CH2_PAIR_COMPLEMENTARY_MODE PWM2L and PWM2H will in complementary mode.
    _PWM_MC_CH3_PAIR_INDEPENDENT_MODE PWM3L and PWM3H will in independent mode.
    _PWM_MC_CH3_PAIR_COMPLEMENTARY_MODE PWM3L and PWM3H will in complementary mode.
    _PWM_MC_CH4_PAIR_INDEPENDENT_MODE PWM4L and PWM4H will in independent mode.
    _PWM_MC_CH4_PAIR_COMPLEMENTARY_MODE PWM4L and PWM4H will in complementary mode.

  • enable_channel: enable PWM channel. Valid values are given in the table below :
    Value Description
    _PWM_MC_CH1L Enable PWM1L channel.
    _PWM_MC_CH2L Enable PWM2L channel.
    _PWM_MC_CH3L Enable PWM3L channel.
    _PWM_MC_CH4L Enable PWM4L channel.
    _PWM_MC_CH1H Enable PWM1H channel.
    _PWM_MC_CH2H Enable PWM2H channel.
    _PWM_MC_CH3H Enable PWM3H channel.
    _PWM_MC_CH4H Enable PWM4H channel.

  • clock_prescale_output_postscale: PWM clock prescaler/postscaler settings. Values <0..3> and <0..15> correspond to prescaler/postscaler <1:1, 1:4, 1:16, 1:64> and <1:1, 1:2, ..., 1:16>

(II)

  • freq_hz: PWM frequency in Hz (refer to device datasheet for correct values in respect with Fosc)

  • pair_output_mode: output mode for output pin pairs: 1 = independent, 0 = complementary (for dsPIC33EPXXGS50X, dsPIC33EPXXGS202 and dsPIC33EVXXXGM00X_10X 0 = independent, 1 = complementary)
    If pair_output_mode.B0 is equal to 1 then PWM channels PWM1L and PWM1H will be independent (for dsPIC33EPXXGS50X, dsPIC33EPXXGS202 and dsPIC33EVXXXGM00X_10X complementary),
    If pair_output_mode.B1 is equal to 0 then PWM channels PWM2L and PWM2H will be complementary (for dsPIC33EPXXGS50X, dsPIC33EPXXGS202 and dsPIC33EVXXXGM00X_10X independent),
    • ...
    If pair_output_mode.Bn is equal to 1 then PWM channels PWM(n+1)L and PWM(n+1)H will be independent (for dsPIC33EPXXGS50X, dsPIC33EPXXGS202 and dsPIC33EVXXXGM00X_10X complementary),
    If pair_output_mode.Bn is equal to 0 then PWM channels PWM(n+1)L and PWM(n+1)H will be complementary (for dsPIC33EPXXGS50X, dsPIC33EPXXGS202 and dsPIC33EVXXXGM00X_10X independent).

  • enable_output_x: bits <7..0> are enabling corresponding PWM channels (PWM4H, PWM3H, PWM2H, PWM1H, PWM4L, PWM3L, PWM2L, PWM1L).
    (for dsPIC33EPXXGS50X, dsPIC33EPXXGS202 and dsPIC33EVXXXGM00X_10X PWM5H, PWM5L, PWM4H, PWM4L, PWM3H, PWM3L, PWM2H, PWM2L, PWM1H, PWM1L)
    If bit value is equal to 0 then corresponding PWM channel is disabled (pin is standard I/O).
    If bit value is equal to 1 then corresponding PWM channel is enabled (pin is PWM output).
    For detalied explanation consult the "Motor Control PWM Module" section in device datasheet.

  • clock_prescale_output_postscale: PWM clock prescaler/postscaler settings. Values <0..3> and <0..15> correspond to prescaler/postscaler <1:1, 1:4, 1:16, 1:64> and <1:1, 1:2, ..., 1:16>

(III)

  • freq_hz: PWM frequency in Hz (refer to device datasheet for correct values in respect with Fosc).
  • primary : chose beetween primary and secondary clock register, valid values :
    Value Description
    _PWM_MC_CLK_PRIMARY Primary clock register.
    _PWM_MC_CLK_SECONDARY Secondary clock register.
  • clock_prescale: PWM clock prescaler settings.
Returns

Calculated timer period.
Requires

The dsPIC30/33 MCU must have the Motor Control PWM module.
Example 
// Initializes the PWM1 module at 5KHz, complementary pin-pair output, output enabled on pins 4l..1l, no clock prescale and no clock postscale:
unsigned int duty_50;
...
duty_50 = PWM1_Mc_Init(5000, 1, 0x0F, 0);
Notes
  • Number of PWM modules per MCU differs from chip to chip. Please, read the appropriate datasheet before utilizing this library.
  • PWM library routines require you to specify the module you want to use. To use the desired PWM module, simply change the letter x in the routine prototype for a number from 1 to 2.

PWMx_Mc_Set_Duty

Prototype

void PWM1_Mc_Set_Duty(unsigned duty, unsigned channel);

// For dsPIC 33FJ MCUs that have PWM2 module :
void PWM2_Mc_Set_Duty(unsigned duty);

void PWM_MC_Set_Duty(unsigned duty, unsigned primary, unsigned channel);

Description

The function changes PWM duty ratio.
Parameters
  • duty: PWM duty ratio. Valid values: 0 to timer period returned by the PWMx_Mc_Init function.
  • channel: number of PWM channel to change duty to.
  • primary : chose beetween primary and secondary clock register.
    Value Description
    _PWM_MC_DUTY_PRIMARY Primary duty cycle register.
    _PWM_MC_DUTY_SECONDARY Secondary duty cycle register.
Returns

Nothing.
Requires

The dsPIC30/33 MCU must have the Motor Control PWM module.

The PWM module needs to be initalized. See the PWMx_Mc_Init function.
Example 
// Set duty ratio to 50% at channel 1:
PWM1_Mc_Init(5000,1,0xF,0);
...
PWM1_Mc_Set_Duty(32767, 1);
Notes
  • Number of PWM modules per MCU differs from chip to chip. Please, read the appropriate datasheet before utilizing this library.
  • PWM library routines require you to specify the module you want to use. To use the desired PWM module, simply change the letter x in the routine prototype for a number from 1 to 2.

PWM_MC_Set_Master_Duty

Prototype

void PWM_MC_Set_Master_Duty(unsigned duty);
Description

This function updates master duty cycle register.
Parameters
  • duty: PWM duty ratio. Valid values: 0 to timer period returned by the PWMx_Mc_Init function.
Returns

Nothing.
Requires

The PWM module needs to be initalized. See the PWMx_Mc_Init function.
Example 
// Set duty ratio to 50% :
PWM_MC_Set_Master_Duty(32768);
Notes
  • This routine is avaliable only for dsPIC33EPXXX(GP/MC/MU)806/810/814 and PIC24EPXXX(GP/GU)810/814 family.

PWMx_Mc_Start

Prototype

void PWMx_Mc_Start();
Description

Starts the Motor Control PWM module (channels initialized in the PWMx_Mc_Init function).
Parameters

None.
Returns

Nothing.
Requires

The dsPIC30/33 MCU must have the Motor Control PWM module.

The PWM module needs to be initalized. See the PWMx_Mc_Init function.
Example 
// start the Motor Control PWM1 module
PWM1_Mc_Start();
Notes
  • Number of PWM modules per MCU differs from chip to chip. Please, read the appropriate datasheet before utilizing this library.
  • PWM library routines require you to specify the module you want to use. To use the desired PWM module, simply change the letter x in the routine prototype for a number from 1 to 2.

PWMx_Mc_Stop

Prototype

void PWMx_Mc_Stop();
Description

Stops the Motor Control PWM module.
Parameters

None.
Returns

Nothing.
Requires

The dsPIC30/33 MCU must have the Motor Control PWM module.
Example 
// stop the Motor Control PWM1 module 
PWM1_Mc_Stop();
Notes
  • Number of PWM modules per MCU differs from chip to chip. Please, read the appropriate datasheet before utilizing this library.
  • PWM library routines require you to specify the module you want to use. To use the desired PWM module, simply change the letter x in the routine prototype for a number from 1 to 2.

PWM_MC_Init_Channel

Prototype

void PWM_MC_Init_Channel(unsigned pinEnableMask, unsigned mode, unsigned clk, unsigned masterDutyCycle, unsigned channel);
Description

This function initializes single PWM channel.
Parameters
  • pinEnableMask: PWM Output Pin Ownership bit, valid values :
    Value Description
    _PWM_MC_ENABLE_LOW_PIN PWM module controls PWMxL pin.
    _PWM_MC_ENABLE_HIGH_PIN PWM module controls PWMxH pin.

  • mode: PWM I/O Pin Mode bits, valid values :
    Value Description
    _PWM_MC_TRUE_INDEPENDENT PWM I/O pin pair is in the True Independent Output mode.
    _PWM_MC_PUSH_PULL PWM I/O pin pair is in the Push-Pull Output mode.
    _PWM_MC_REDUNDANT PWM I/O pin pair is in the Redundant Output mode.
    _PWM_MC_COMPLEMENTARY PWM I/O pin pair is in the Complementary Output mode.

  • primary: choose beetween primary and secondary clock register, valid values :
    Value Description
    _PWM_MC_CLK_PRIMARY Primary clock register.
    _PWM_MC_CLK_SECONDARY Secondary clock register.

  • masterDutyCycle: Enable/disable master duty cycle register, valid values :
    Value Description
    _PWM_MC_MDC_ENABLE Enable master duty cycle register.
    _PWM_MC_MDC_DISABLE Disable master duty cycle register.

  • channel: PWM channel selection, valid values :
    Value Description
    _PWM_MC_CH1 PWM channel 1.
    _PWM_MC_CH2 PWM channel 2.
    _PWM_MC_CH3 PWM channel 3.
    _PWM_MC_CH4 PWM channel 4.
    _PWM_MC_CH5 PWM channel 5.
    _PWM_MC_CH6 PWM channel 6.
    _PWM_MC_CH7 PWM channel 7.
    _PWM_MC_CH8 PWM channel 8.
    _PWM_MC_CH9 PWM channel 9.
    _PWM_MC_CH10 PWM channel 10.
    _PWM_MC_CH11 PWM channel 11.
    _PWM_MC_CH12 PWM channel 12.
Returns

Nothing.
Requires

This routine should not be called after PWM is started.
Example 
PWM_MC_Init_Channel(_PWM_MC_ENABLE_LOW_PIN, _PWM_MC_TRUE_INDEPENDENT, _PWM_MC_CLK_PRIMARY, _PWM_MC_MDC_ENABLE, _PWM_MC_CH1);
Notes
  • This routine is avaliable only for dsPIC33EPXXX(GP/MC/MU)806/810/814 and PIC24EPXXX(GP/GU)810/814 family.

Library Example

The example changes PWM duty ratio on channel 1 continually. If LED is connected to the channel 1, a gradual change of emitted light will be noticeable.

Copy Code To ClipboardCopy Code To Clipboard 
unsigned int i;

unsigned int duty_50;

void main(){

      ADPCFG = 0xFFFF;                            // initialize AN pins as digital
      PORTB  = 0xAAAA;
      TRISB  = 0;                                 // initialize portb as output
      Delay_ms(1000);

      duty_50 = PWM1_MC_Init(5000, 0, 0x01, 0);   // Pwm_Mc_Init returns 50% of the duty
      PWM1_MC_Set_Duty(i = duty_50, 1);
      PWM1_MC_Start();

      do
      {
        i--;
        PWM1_MC_Set_Duty(i, 1);
        Delay_ms(10);
        if (i == 0)
          i = duty_50 * 2 - 1;                    // Let us not allow the overflow
        PORTB = i;
      }
      while(1);

}

HW Connection

PWM Motor Control demonstration

PWM Motor Control demonstration

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