PWM measurement

Module XML file: pwm_meas.xml

PWM input measurement mcu periph access and init wrapper for other modules.

  For LPC21xx on the TWOG:
  - INPUT CAPTURE CAP0.3 on P0.29 (TWOG ADC5, 5V to 3.3V voltage divider)
  - INPUT CAPTURE CAP0.0 on P0.30 (TWOG ADC4, no voltage divider)

  For STM32:
  - each board (or airframe file) has to define the PWM input pin and parameters
  - example can be found in sw/airborne/boards/apogee_1.0.h board file

Example for airframe file

This example contains all possible configuration options, not all of them are mandatory!

<modules>
  <load name="pwm_meas.xml">
    <define name="USE_PWM_INPUT1" value="PWM_PULSE_TYPE_ACTIVE_LOW|PWM_PULSE_TYPE_ACTIVE_HIGH" />
    <define name="USE_PWM_INPUT2" value="PWM_PULSE_TYPE_ACTIVE_LOW|PWM_PULSE_TYPE_ACTIVE_HIGH" />
  </load>
</modules>

Module configuration options

Define Options

• name: USE_PWM_INPUT1 value: PWM_PULSE_TYPE_ACTIVE_LOW|PWM_PULSE_TYPE_ACTIVE_HIGH
  Description: Activate PWM input 1 and select polarity
• name: USE_PWM_INPUT2 value: PWM_PULSE_TYPE_ACTIVE_LOW|PWM_PULSE_TYPE_ACTIVE_HIGH
  Description: Activate PWM input 2 and select polarity

Module functions

Init Functions

These initialization functions are called once on startup.

• pwm_meas_init()

Files

Header Files

The following headers are automatically included in modules.h

• pwm_meas.h

Source Files

• modules/core/pwm_meas.c
• mcu_periph/pwm_input.c
• arch dependent: mcu_periph/pwm_input_arch.c

Raw pwm_meas.xml file:

<!DOCTYPE module SYSTEM "module.dtd">

<module name="pwm_meas" dir="core">
  <doc>
    <description>
      PWM measurement.

      PWM input measurement mcu periph access and init wrapper for other modules.

      For LPC21xx on the TWOG:
      - INPUT CAPTURE CAP0.3 on P0.29 (TWOG ADC5, 5V to 3.3V voltage divider)
      - INPUT CAPTURE CAP0.0 on P0.30 (TWOG ADC4, no voltage divider)

      For STM32:
      - each board (or airframe file) has to define the PWM input pin and parameters
      - example can be found in sw/airborne/boards/apogee_1.0.h board file
    </description>
    <define name="USE_PWM_INPUT1" value="PWM_PULSE_TYPE_ACTIVE_LOW|PWM_PULSE_TYPE_ACTIVE_HIGH" description="Activate PWM input 1 and select polarity"/>
    <define name="USE_PWM_INPUT2" value="PWM_PULSE_TYPE_ACTIVE_LOW|PWM_PULSE_TYPE_ACTIVE_HIGH" description="Activate PWM input 2 and select polarity"/>
  </doc>
  <header>
    <file name="pwm_meas.h"/>
  </header>
  <init fun="pwm_meas_init()"/>
  <makefile target="ap">
    <file name="pwm_meas.c"/>
    <file name="pwm_input.c" dir="mcu_periph"/>
    <file_arch name="pwm_input_arch.c" dir="mcu_periph"/>
    <define name="USE_PWM_INPUT"/> <!-- needed to enable the pwm_input interrupts in mcu_periph/sys_time_arch.c -->
  </makefile>
</module>