Motor/GPIO (Simulating Motor With LEDs)

See also

• libgpiod

Goal

Create a Motor implementation, MotorLED, that does not rreally drive a motor. Rather it uses two LEDs - forward and backward - that are used as indicators for the motor driving direction. Both off means “motor idle”. The LEDs are driven using libgpiod.

How

class MotorLED : public Motor
{
public:
    MotorLED(const std::string& gpiodevice, int line_number_forward, int line_number_backward);
    ...
};

• gpiodevice is for example /dev/gpiochip0

• line_number_forward and line_number_backward are the numbers of the respective GPIO line (see for example the Raspberry Pi pinout diagram)

Use the libgpiod library to implement the forward(), backward(), and stop() methods.

Testing

Real hardware cannot be tested using unit tests (at least not easily). Write a test program (in tests/) that uses MotorLED to manipulate the LED states.