robocar-pca9685/actuator/steering.go

package actuator

import (
	"github.com/cyrilix/robocar-pca9685/util"
	log "github.com/sirupsen/logrus"
	"periph.io/x/periph/conn/gpio"
	"periph.io/x/periph/experimental/devices/pca9685"
)

const (
	LeftAngle  = -1.
	RightAngle = 1.
)

type Steering struct {
	channel           int
	leftPWM, rightPWM int
	dev               *pca9685.Dev
}

func (s *Steering) SetPulse(pulse int) {
	err := s.dev.SetPwm(s.channel, 0, gpio.Duty(pulse))
	if err != nil {
		log.Warningf("unable to set steering pwm value: %v", err)
	}

}

// Set percent value steering
func (s *Steering) SetPercentValue(p float32) {
	// map absolute angle to angle that vehicle can implement.
	pulse := util.MapRange(float64(p), LeftAngle, RightAngle, float64(s.leftPWM), float64(s.rightPWM))
	s.SetPulse(pulse)
}

func NewSteering(channel, leftPWM, rightPWM int) *Steering {
	t := Steering{
		channel:  channel,
		dev:      device,
		leftPWM:  leftPWM,
		rightPWM: rightPWM,
	}
	return &t
}