Adding driver for rotary encoder support

encoders/quadrature_device.go

@@ -0,0 +1,34 @@
+package encoders
+
+type QuadratureDevice struct {
+	cfg  QuadratureConfig
+	impl quadratureImpl
+}
+
+type QuadratureConfig struct {
+	Precision int
+}
+
+type quadratureImpl interface {
+	configure(cfg QuadratureConfig) error
+	readValue() int
+	writeValue(int)
+}
+
+func (enc *QuadratureDevice) Configure(cfg QuadratureConfig) error {
+	if cfg.Precision < 1 {
+		cfg.Precision = 4
+	}
+	enc.cfg = cfg
+	return enc.impl.configure(cfg)
+}
+
+// Position returns the stored int value for the encoder
+func (enc *QuadratureDevice) Position() int {
+	return enc.impl.readValue() / enc.cfg.Precision
+}
+
+// SetPosition overwrites the currently stored value with the specified int value
+func (enc *QuadratureDevice) SetPosition(v int) {
+	enc.impl.writeValue(v * enc.cfg.Precision)
+}