optimizie waiting operations

e220/e220.go

@@ -91,6 +91,10 @@ func (d *Device) Configure(startupE220Mode uint8) error {
 		return err
 	}
 
+	// AUX Pin becomes Low Level for about 30ms after the E220 is started.
+	// therefore, wait until transmission/reception becomes possible.
+	time.Sleep(50 * time.Millisecond)
+
 	return nil
 }
 
@@ -113,9 +117,6 @@ func (d *Device) SetMode(mode uint8) error {
 		return fmt.Errorf("Invalid mode: %d", mode)
 	}
 
-	// AUX Pin becomes Low Level for about 20ms after the mode is changed
-	time.Sleep(30 * time.Millisecond)
-
 	return nil
 }
 
@@ -135,10 +136,6 @@ func (d *Device) ReadRegister(startAddr uint8, length uint8) ([]byte, error) {
 		return nil, fmt.Errorf("unexpected response: %X", response)
 	}
 
-	// Wait for about 50ms because requests are not accepted for a while
-	// after register access (= Format error: 0xFF 0xFF0x FF is returned)
-	time.Sleep(50 * time.Millisecond)
-
 	return response, nil
 }
 
@@ -155,10 +152,6 @@ func (d *Device) WriteRegister(startAddr uint8, params []byte) error {
 			[]byte{0xC1, startAddr, byte(len(params))}, params, response)
 	}
 
-	// Wait for about 50ms because requests are not accepted for a while
-	// after register access (= Format error: 0xFF 0xFF0x FF is returned)
-	time.Sleep(50 * time.Millisecond)
-
 	return nil
 }