added error message

main.go

@@ -12,7 +12,10 @@ func main() {
 	host.Init()
 	t := time.NewTicker(500 * time.Millisecond)
 	for l := gpio.Low; ; l = !l {
-		orangepi.PA1_8.Out(l)
+		err := orangepi.PA1_8.Out(l)
+		if err != nil {
+			fmt.Printf("%s", err)
+		}
 		<-t.C
 		fmt.Println("tick")