diff --git a/tests/drivers/at/main.c b/tests/drivers/at/main.c
index 31a38092c0..46a7f22eea 100644
--- a/tests/drivers/at/main.c
+++ b/tests/drivers/at/main.c
@@ -35,6 +35,8 @@ static at_dev_t at_dev;
 static char buf[256];
 static char resp[1024];
 static char rp_buf[256];
+static bool initialized = false;
+static bool is_power_on = false;
 
 static int init(int argc, char **argv)
 {
@@ -72,6 +74,8 @@ static int init(int argc, char **argv)
         return 1;
     }
 
+    initialized = true;
+
     return res;
 }
 
@@ -82,6 +86,18 @@ static int send(int argc, char **argv)
         return 1;
     }
 
+    if (initialized == false) {
+        puts("Error: AT device not initialized.\n");
+        puts("Execute init function first.\n");
+        return 1;
+    }
+
+    if (is_power_on == false) {
+        puts("Error: AT device not power on.\n");
+        puts("Execute power_on function first.\n");
+        return 1;
+    }
+
     ssize_t len;
     if ((len = at_send_cmd_get_resp(&at_dev, argv[1], resp, sizeof(resp), 10 * US_PER_SEC)) < 0) {
         puts("Error");
@@ -100,6 +116,18 @@ static int send_ok(int argc, char **argv)
         return 1;
     }
 
+    if (initialized == false) {
+        puts("Error: AT device not initialized.\n");
+        puts("Execute init function first.\n");
+        return 1;
+    }
+
+    if (is_power_on == false) {
+        puts("Error: AT device not power on.\n");
+        puts("Execute power_on function first.\n");
+        return 1;
+    }
+
     if (at_send_cmd_wait_ok(&at_dev, argv[1], 10 * US_PER_SEC) < 0) {
         puts("Error");
         return 1;
@@ -117,6 +145,18 @@ static int send_lines(int argc, char **argv)
         return 1;
     }
 
+    if (initialized == false) {
+        puts("Error: AT device not initialized.\n");
+        puts("Execute init function first.\n");
+        return 1;
+    }
+
+    if (is_power_on == false) {
+        puts("Error: AT device not power on.\n");
+        puts("Execute power_on function first.\n");
+        return 1;
+    }
+
     ssize_t len;
     if ((len = at_send_cmd_get_lines(&at_dev, argv[1], resp, sizeof(resp),
                                          10 * US_PER_SEC)) < 0) {
@@ -138,6 +178,18 @@ static int send_recv_bytes(int argc, char **argv)
         return 1;
     }
 
+    if (initialized == false) {
+        puts("Error: AT device not initialized.\n");
+        puts("Execute init function first.\n");
+        return 1;
+    }
+
+    if (is_power_on == false) {
+        puts("Error: AT device not power on.\n");
+        puts("Execute power_on function first.\n");
+        return 1;
+    }
+
     sprintf(buffer, "%s%s", argv[1], CONFIG_AT_SEND_EOL);
     at_send_bytes(&at_dev, buffer, strlen(buffer));
 
@@ -160,6 +212,18 @@ static int send_recv_bytes_until_string(int argc, char **argv)
         return 1;
     }
 
+    if (initialized == false) {
+        puts("Error: AT device not initialized.\n");
+        puts("Execute init function first.\n");
+        return 1;
+    }
+
+    if (is_power_on == false) {
+        puts("Error: AT device not power on.\n");
+        puts("Execute power_on function first.\n");
+        return 1;
+    }
+
     sprintf(buffer, "%s%s", argv[1], CONFIG_AT_SEND_EOL);
     at_send_bytes(&at_dev, buffer, strlen(buffer));
     memset(buffer, 0, sizeof(buffer));
@@ -192,6 +256,7 @@ static int power_on(int argc, char **argv)
     (void)argv;
 
     at_dev_poweron(&at_dev);
+    is_power_on = true;
 
     puts("Powered on");
 
@@ -204,6 +269,7 @@ static int power_off(int argc, char **argv)
     (void)argv;
 
     at_dev_poweroff(&at_dev);
+    is_power_on = false;
 
     puts("Powered off");