Subsystem Best Practices

note

The code from the previous subsystem tutorials is perfectly good, and there is no new functionality in the code below.

The code below is cleaner and nicer, but there is no new functionality.

Why?

Separating code out into more files can make the code more readable and easier to maintain over time. Some principles to go by:

• main.cpp and autons.cpp should be calling functions, try not to create anything subsystem specific in those files
• main.cpp and autons.cpp should call the same functions to do something, you shouldn't have different ways of calling something in each file
• give each subsystem its own file
• wrap objects so maintenance is easier down the line

.hpp and .cpp

For each subsystem, I like to create a .cpp and .hpp file. This helps separate all the code out. In the .hpp file, create all of your motors/pistons/sensors with inline object. You'll also put all of your function names here that you want accessible in main.cpp and autons.cpp.

Intake Example

In intake.hpp I would create all of my motors and any sensors if they're being used for the intake.

In the example below, set_intake() is a wrapper for spinning the motor. This allows us to later modify this function and do something else every time the intake is called. This can include adding more motors, setting flags for anti-jam. Having wrappers like this make maintenance easier over time.

We also have intake_opcontrol() which is how we'll be controlling the intake. This makes our main.cpp very clean as we'll just need to call intake_opcontrol();.

include/intake.hpp

#pragma once

#include "EZ-Template/api.hpp"
#include "api.h"

inline pros::Motor intake(10);  // Make this number negative if you want to reverse the motor

void set_intake(int input);
void intake_opcontrol();

Before we can use these functions in intake.cpp, we need to #include "intake.hpp" in main.h.
include/main.h

// . . .
/**
 * You should add more #includes here
 */
// #include "okapi/api.hpp"
// #include "pros/api_legacy.h"
#include "EZ-Template/api.hpp"

// More includes here...
#include "autons.hpp"
#include "subsystems.hpp"
#include "intake.hpp"
// . . .

Now we can define our functions in intake.cpp.
src/intake.cpp

#include "main.h"

void set_intake(int input) {
  intake.move(input);
}

void intake_opcontrol() {
  if (master.get_digital(DIGITAL_L1)) {
    set_intake(127);
  } 
  else if (master.get_digital(DIGITAL_L2)) {
    set_intake(-127);
  } 
  else {
    set_intake(0);
  }
}

Our main.cpp is very clean only containing function calls.
src/main.cpp

// . . .
void opcontrol() {
  chassis.drive_brake_set(MOTOR_BRAKE_COAST);  // This is preference to what you like to drive on

  while (true) {
    ez_template_extras();      // Gives you some extras to make EZ-Template ezier
    chassis.opcontrol_tank();  // Tank control
    intake_opcontrol();        // Intake control

    pros::delay(ez::util::DELAY_TIME);  // This is used for timer calculations!  Keep this ez::util::DELAY_TIME
  }
}

In autons.cpp, we'll need to make sure we're using the wrapper set_intake() we made earlier.
src/autons.cpp

void intake_autonomous() {
  chassis.pid_drive_set(24_in, DRIVE_SPEED, true);
  chassis.pid_wait_until(6_in);
  set_intake(127);
  chassis.pid_wait_quick_chain();
  set_intake(0);

  chassis.pid_turn_set(45_deg, TURN_SPEED);
  chassis.pid_wait_quick_chain();

  chassis.pid_turn_set(-45_deg, TURN_SPEED);
  chassis.pid_wait_quick_chain();

  chassis.pid_turn_set(0_deg, TURN_SPEED);
  chassis.pid_wait();

  set_intake(-127);
  chassis.pid_drive_set(-24_in, DRIVE_SPEED, true);
  chassis.pid_speed_max_set(DRIVE_SPEED);  
  chassis.pid_wait();
  set_intake(0);
}

Piston Example

In doinker.hpp we can create all of our pistons and anything else we're using for the doinker.

In the example below, set_doinker() is a wrapper for setting the piston. This allows us to later modify this function and do something else every time the doinker is called. This can include adding more pistons, setting flags for other subsystems, etc. Having wrappers like this make maintenance easier over time.

We also have doinker_opcontrol() which is how we'll be controlling the intake. This makes our main.cpp very clean as we'll just need to call doinker_opcontrol();.

include/doinker.hpp

#pragma once

#include "EZ-Template/api.hpp"
#include "api.h"

inline ez::Piston doinker('A');

void set_doinker(bool input);
void doinker_opcontrol();

Before we can use these functions in doinker.cpp, we need to #include "doinker.hpp" in main.h.
include/main.h

// . . .
/**
 * You should add more #includes here
 */
// #include "okapi/api.hpp"
// #include "pros/api_legacy.h"
#include "EZ-Template/api.hpp"

// More includes here...
#include "autons.hpp"
#include "subsystems.hpp"
#include "intake.hpp"
#include "doinker.hpp"
// . . .

Now we can define our functions in doinker.cpp.
src/doinker.cpp

#include "main.h"

void set_doinker(bool input) {
  doinker.set(input);
}

void doinker_opcontrol() {
  doinker.button_toggle(master.get_digital_new_press(DIGITAL_R1));
}

Our main.cpp is very clean only containing function calls.
src/main.cpp

// . . .
void opcontrol() {
  chassis.drive_brake_set(MOTOR_BRAKE_COAST);  // This is preference to what you like to drive on

  while (true) {
    ez_template_extras();      // Gives you some extras to make EZ-Template ezier
    chassis.opcontrol_tank();  // Tank control
    intake_opcontrol();        // Intake control
    doinker_opcontrol();       // Doinker control

    pros::delay(ez::util::DELAY_TIME);  // This is used for timer calculations!  Keep this ez::util::DELAY_TIME
  }
}

In autons.cpp, we'll need to make sure we're using the wrapper set_doinker() we made earlier.
src/autons.cpp

void intake_autonomous() {
  chassis.pid_drive_set(24_in, DRIVE_SPEED, true);
  chassis.pid_wait_until(6_in);
  set_intake(127);
  chassis.pid_wait_quick_chain();
  set_intake(0);

  set_doinker(true);
  chassis.pid_turn_set(45_deg, TURN_SPEED);
  chassis.pid_wait_quick_chain();

  chassis.pid_turn_set(-45_deg, TURN_SPEED);
  chassis.pid_wait_quick_chain();

  chassis.pid_turn_set(0_deg, TURN_SPEED);
  chassis.pid_wait();
  set_doinker(false);

  set_intake(-127);
  chassis.pid_drive_set(-24_in, DRIVE_SPEED, true);
  chassis.pid_speed_max_set(DRIVE_SPEED);  
  chassis.pid_wait();
  set_intake(0);
}