diff --git a/main.c b/main.c
index a8e08c0..1b10ce9 100644
--- a/main.c
+++ b/main.c
@@ -534,9 +534,12 @@ void main(void)
 		}
 		numbers[number].number = (bytes[0]<<8)+bytes[1];
 		mux_select(number);
+		printf("number %u: ", number);
 		if (0xffff==numbers[number].number) {
+			printf("off\n");
 			led_tm1637_off();
 		} else {
+			printf("%u\n", numbers[number].number);
 			led_tm1637_number(numbers[number].number);
 		}
 	}