diff --git a/source/application/test/main.c b/source/application/test/main.c
index f98855d..1079e84 100644
--- a/source/application/test/main.c
+++ b/source/application/test/main.c
@@ -21,10 +21,17 @@ struct thread_context tc_1;
 
 void task1(void *arg)
 {
+	char rd = '0';
 	open(&led_4);
-	write(&led_4, 0, 1);
+	write(&led_4, &rd, 1);
 	while(1) {
 		sleep_ms(1000);
+		read(&led_4, &rd, 1);
+		if(rd == '0')
+			rd = '1';
+		else
+			rd = '0';
+		write(&led_4, &rd, 1);
 		write(&uart_1, "Driver test\r\n", 13);
 	}
 }
diff --git a/source/firmware/kernel/driver/driver.c b/source/firmware/kernel/driver/driver.c
index 2203945..06b4747 100644
--- a/source/firmware/kernel/driver/driver.c
+++ b/source/firmware/kernel/driver/driver.c
@@ -110,7 +110,7 @@ int write(const struct driver *driver, const char *buffer, int len)
 	case DRIVER_TYPE_GPIO:
 		if(len > 0) {
 			char send = 0;
-			if(buffer[0])
+			if((buffer[0] - 0x30) > 0)
 				send = 1;
 			gpio_write((const struct gpio *)(driver->device_driver), send);
 			ret = 1;