forked from gaganjyot/GoIoTLights
/
servo.go
46 lines (36 loc) · 861 Bytes
/
servo.go
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// Package servo allows control of servos using a PWM controller.
package servo
import (
"github.com/golang/glog"
"github.com/kidoman/embd/util"
)
const (
minus = 544
maxus = 2400
)
const (
// DefaultFreq represents the default (preferred) freq of a PWM doing servo duties.
DefaultFreq = 50
)
// A PWM interface implements access to a pwm controller.
type PWM interface {
SetMicroseconds(us int) error
}
type Servo struct {
PWM PWM
Minus, Maxus int
}
// New creates a new Servo interface.
func New(pwm PWM) *Servo {
return &Servo{
PWM: pwm,
Minus: minus,
Maxus: maxus,
}
}
// SetAngle sets the servo angle.
func (s *Servo) SetAngle(angle int) error {
us := util.Map(int64(angle), 0, 180, int64(s.Minus), int64(s.Maxus))
glog.V(1).Infof("servo: given angle %v calculated %v us", angle, us)
return s.PWM.SetMicroseconds(int(us))
}