cl_ros2_timer

The cl_ros2_timer package

README

cl_ros2_timer

Timer-based orthogonal behaviors for SMACC2 state machines. The OrTimer orthogonal holds a ClRos2Timer client; each behavior (CbTimerCountdownOnce, CbTimerCountdownLoop) creates its own dedicated wall timer for accurate, period-independent firing.

Setting Up the Orthogonal

Define an OrTimer orthogonal in your state machine:

// orthogonals/or_timer.hpp
#include "cl_ros2_timer/cl_ros2_timer.hpp"
#include "smacc2/smacc.hpp"

class OrTimer : public smacc2::Orthogonal<OrTimer>
{
public:
  void onInitialize() override
  {
    this->createClient<cl_ros2_timer::ClRos2Timer>();
  }
};

Register it in your state machine’s onInitialize():

void onInitialize() override
{
  this->createOrthogonal<OrTimer>();
}

CbTimerCountdownOnce

Header: cl_ros2_timer/client_behaviors/cb_timer_countdown_once.hpp

Posts EvTimer once after the specified duration, then stops. Use this to drive a timed transition out of a state.

// In state's staticConfigure():
configure_orthogonal<OrTimer, CbTimerCountdownOnce>(5s);    // fire once after 5 seconds
configure_orthogonal<OrTimer, CbTimerCountdownOnce>(4min);  // fire once after 4 minutes
configure_orthogonal<OrTimer, CbTimerCountdownOnce>(500ms); // fire once after 500 ms

Full state example:

struct StWaitForSensor : smacc2::SmaccState<StWaitForSensor, MyStateMachine>
{
  using reactions = mpl::list<
    Transition<EvTimer<CbTimerCountdownOnce, OrTimer>, StNextState, SUCCESS>>;

  static void staticConfigure()
  {
    configure_orthogonal<OrTimer, CbTimerCountdownOnce>(10s);
  }
};

CbTimerCountdownLoop

Header: cl_ros2_timer/client_behaviors/cb_timer_countdown_loop.hpp

Posts EvTimer repeatedly at the specified interval. Use this for periodic actions within a state.

configure_orthogonal<OrTimer, CbTimerCountdownLoop>(3s);    // fire every 3 seconds
configure_orthogonal<OrTimer, CbTimerCountdownLoop>(500ms); // fire every 500 ms
configure_orthogonal<OrTimer, CbTimerCountdownLoop>(1min);  // fire every minute

Chrono Literal Reference

Requires using namespace std::chrono_literals; — already in scope via rclcpp headers in standard SMACC2 state files.

Literal	Meaning	Example
`ms`	milliseconds	`500ms`
`s`	seconds	`5s`
`min`	minutes	`4min`
`h`	hours	`2h`