diff --git a/src/robomaster.c b/src/robomaster.c
index 6dfbd1b..6c08b74 100644
--- a/src/robomaster.c
+++ b/src/robomaster.c
@@ -61,6 +61,19 @@ set_sdk_connection_req_new (
 const Message
 set_system_led_req_new (
 		Client session,
-		struct SetSystemLedReq* msg ) {
-    return message_new(session, 0x3F, SET_SYSTEM_LED_CMDID, sizeof(struct SetSystemLedReq), msg);
+		uint8_t red,
+		uint8_t green,
+		uint8_t blue,
+		enum LEDCOMP comp,
+		uint16_t led_mask,
+		enum LEDEFFECT effect,
+		uint16_t t1,
+		uint16_t t2 ) {
+    const struct SetSystemLedReq msg = {
+        comp, led_mask,
+	{ effect, 7 },
+	red, green, blue,
+	0, t1, t2
+    };
+    return message_new(session, 0x3F, SET_SYSTEM_LED_CMDID, sizeof(msg), &msg);
 }
diff --git a/src/robomaster.h b/src/robomaster.h
index 075d3e7..dcb8299 100644
--- a/src/robomaster.h
+++ b/src/robomaster.h
@@ -149,36 +149,47 @@ const Message get_version_req_new(Client session);
 static const uint8_t SET_SYSTEM_LED_CMDID = 0x33;
 
 enum LEDCOMP {
-    LEDCOMP_BOTTOM_BACK = 0x1;
-    LEDCOMP_BOTTOM_FRONT = 0x2;
-    LEDCOMP_BOTTOM_LEFT = 0x4;
-    LEDCOMP_BOTTOM_RIGHT = 0x8;
-    LEDCOMP_BOTTOM_ALL = 0xf;
-    LEDCOMP_TOP_LEFT = 0x10;
-    LEDCOMP_TOP_RIGHT = 0x20;
-    LEDCOMP_TOP_ALL = 0x30;
-    LEDCOMP_ALL = 0x3f;
+    LEDCOMP_BOTTOM_BACK = 0x1,
+    LEDCOMP_BOTTOM_FRONT = 0x2,
+    LEDCOMP_BOTTOM_LEFT = 0x4,
+    LEDCOMP_BOTTOM_RIGHT = 0x8,
+    LEDCOMP_BOTTOM_ALL = 0xf,
+    LEDCOMP_TOP_LEFT = 0x10,
+    LEDCOMP_TOP_RIGHT = 0x20,
+    LEDCOMP_TOP_ALL = 0x30,
+    LEDCOMP_ALL = 0x3f
 };
 
 enum LEDEFFECT {
-    LEDEFFECT_OFF = 0;
-    LEDEFFECT_ON = 1;
-    LEDEFFECT_BREATH = 2;
-    LEDEFFECT_FLASH = 3;
-    LEDEFFECT_SCROLLING = 4;
+    LEDEFFECT_OFF = 0,
+    LEDEFFECT_ON = 1,
+    LEDEFFECT_BREATH = 2,
+    LEDEFFECT_FLASH = 3,
+    LEDEFFECT_SCROLLING = 4
 };
 
 struct PACKED SetSystemLedReq {
+
+    // Which LEDs on which component to control
     uint32_t comp_mask;
     uint16_t led_mask;
+
     struct {
+        // off, on, flashing, etc.
         uint8_t effect_mode : 4;
+	// Always 7
         uint8_t control_mode : 4;
     };
+
+    // RGB values for the LED color
     uint8_t red;
     uint8_t green;
     uint8_t blue;
+
+    // Always 0
     uint8_t loop;
+
+    // These time intervals have different meaning depending on effect
     uint16_t t1;
     uint16_t t2;
 };
@@ -187,4 +198,14 @@ struct PACKED SetSystemLedResp {
     uint8_t retcode;
 };
 
-const Message set_system_led_req_new(Client session, struct SetSystemLedReq* msg);
+const Message
+set_system_led_req_new (
+		Client session,
+		uint8_t red,
+		uint8_t green,
+		uint8_t blue,
+		enum LEDCOMP comp,
+		uint16_t led_mask,
+		enum LEDEFFECT effect,
+		uint16_t t1,
+		uint16_t t2 );