Skip to content

What is EVA Motors?

Core Concept

EVA Motors is a decorator-based library for behavioral modification of micro-motors. EVA Motors lets you compose behavior by stacking decorators that add specific characteristics like S-curve response, inertia simulation, or kick-start pulses.

Built on EVA Ecosystem

EVA Motors is part of the EVA ecosystem – an event-driven architecture for Arduino. This integration provides:

  • Non-blocking timing – Decorators like InertiaDecor and KickDecor use EVA's Tickable infrastructure
  • Unified update cycle – Single eva::tac() call drives all time-based components
  • Zero-polling design – Components update themselves when needed
#include <evaTac.h>
#include <evamKickstartDecor.h>
using namescpace evam;

using Motor = KickstartDecor<DirectionalMotor<TA6586Driver<9, 10>>>;

void setup(){
    static Motor motor;
    motor.Go(50);  // will overhead initial friction by pulse
}
void loop() {
    eva::tac();
}

Unified Interface

While decorators are the primary focus, this architecture naturally led to interface unification. All motor classes share a consistent Go(value) interface with a standardized range:

  • Signed motors: -1000 to 1000 (-100% to +100%)
  • Unsigned motors: 0 to 1000 (0% to 100%)

This means you can use EVA Motors as a simple motor control library without decorators. Whether you need bidirectional DC motor control, ESC throttle, or servo positioning, the API remains consistent:

using namespace evam;
// Simple motor without decorators
using Motor = DirectionalMotor<TA6586Driver<9, 10>>;
Motor motor;
motor.Go(750);  // 75% forward
motor.Go(-500); // 50% reverse

Standard Combo Stack

The library follows a consistent three-layer architecture:

Layer Components
DECORATORS (Optional) CurveDecor • InertiaDecor • KickDecor
MOTOR (Required) DirectionalMotor • ForwardMotor • SteeringActuator • LinearActuator
DRIVER (Required) PwmDriver • ServoDriver • TA6586 • TB6612 • ~CustomDriver~

Driver layer handles hardware specifics – pin assignments, PWM ranges, protocol details

Motor wrapper provides the unified Go() interface and handles input mapping (dead zones, min/max limits)

Motor wrapper and driver are always required – they form the foundation

Decorators add realistic behavior without modifying the base motor class

using namespace evam;
using BaseMotor = DirectionalMotor<TA6586Driver<9, 10>>;
using PreciseMotor = CurveDecor<BaseMotor, -5>;
using InertialMotor = InertiaDecor<PreciseMotor, 15>;
using SmartMotor = KickDecor<InertialMotor, 25, 900>;
SmartMotor motor;

or more compact:

KickDecor<InertiaDecor<CurveDecor<DirectionalMotor<TA6586Driver<9, 10>>, 5>, 15>, 25, 900> motor;

Extensible Driver Layer

The library features a clean, extensible hardware abstraction layer. Adding support for new motor drivers is straightforward.