diff --git a/firmware/Include/main.h b/firmware/Include/main.h
index 4caf737..69d7ca7 100644
--- a/firmware/Include/main.h
+++ b/firmware/Include/main.h
@@ -37,7 +37,20 @@ extern "C" {
 
 /* Exported types ------------------------------------------------------------*/
 /* USER CODE BEGIN ET */
+struct ui_state {
+  uint8_t oldchannel;
+  enum {
+    UI_STATE_NORMAL = 0, 
+    UI_STATE_MUTE,
+    UI_STATE_SHORT,
+  } state;
 
+  uint8_t gain;
+  uint8_t bboost, tboost;
+  uint8_t latt, ratt;
+};
+
+extern struct ui_state ui_state; // global ui state
 /* USER CODE END ET */
 
 /* Exported constants --------------------------------------------------------*/
@@ -54,6 +67,7 @@ extern "C" {
 void Error_Handler(void);
 
 void set_input(uint8_t channel);
+int get_input();
 void set_attenuation(uint8_t left, uint8_t right);
 void set_mute(uint8_t mute); //< tries to switch to muted ui state
 int is_muted(); //< returns whether the ui is muted
diff --git a/firmware/Src/main.c b/firmware/Src/main.c
index 2e9cf68..cedd0fd 100644
--- a/firmware/Src/main.c
+++ b/firmware/Src/main.c
@@ -102,15 +102,7 @@ int test_button_pressed() {
 #undef TEST_BUTTON
 }
 
-struct ui_state {
-  uint8_t oldchannel;
-  enum {
-    UI_STATE_NORMAL = 0, 
-    UI_STATE_MUTE,
-    UI_STATE_SHORT,
-  } state;
-
-} ui_state = {
+struct ui_state ui_state = {
   .oldchannel = -1,
   .state = UI_STATE_NORMAL,
 };
@@ -131,6 +123,10 @@ void set_input(uint8_t channel) {
 	printf("C%d\n", channel);
 }
 
+int get_input() {
+  return ui_state.oldchannel;
+}
+
 // only mute if the ui allows to 
 void set_mute(uint8_t mute) {
   if(UI_STATE_MUTE == ui_state.state && mute)
@@ -190,8 +186,8 @@ int is_shorted() {
 }
 
 void set_attenuation(uint8_t left, uint8_t right) {
-	bd_set_attenuation(&hi2c1, 0, left);
-	bd_set_attenuation(&hi2c1, 1, right);
+	ui_state.latt = bd_set_attenuation(&hi2c1, 0, left);
+  ui_state.ratt = bd_set_attenuation(&hi2c1, 1, right);
 }
 
 
diff --git a/firmware/Src/message_parser.c b/firmware/Src/message_parser.c
index d67e7ac..081ec61 100644
--- a/firmware/Src/message_parser.c
+++ b/firmware/Src/message_parser.c
@@ -138,16 +138,24 @@ int parse_buffer() {
 			uint16_t gain;
 			if (next_arg_unsigned(&gain)) break;
 
-			printf("G%d\n", bd_set_gain(&hi2c1, gain));
+			printf("G%d\n", (ui_state.gain = bd_set_gain(&hi2c1, gain)));
 		}
 		break;
 	case 'L':
 	case 'R':
 	{
 		uint16_t att;
-		if (next_arg_unsigned(&att)) break;
+		uint8_t dir = 0;
+		uint8_t * save = &ui_state.latt;
 
-		printf("%c%d\n", temp, bd_set_attenuation(&hi2c1, temp == 'R', att&0xFF));
+		if (next_arg_unsigned(&att)) break;
+		
+		if (temp == 'R') {
+			dir = 1;
+			save = &ui_state.ratt;
+		}
+
+		printf("%c%d\n", temp, (*save = bd_set_attenuation(&hi2c1, dir, att&0xFF)));
 	}
 		break;
 	case 'M':
@@ -173,7 +181,7 @@ int parse_buffer() {
 		uint16_t boost;
 		if (next_arg_unsigned(&boost)) break;
 
-		printf("B%d\n", bd_set_bass_boost(&hi2c1, boost));
+		printf("B%d\n", (ui_state.bboost = bd_set_bass_boost(&hi2c1, boost)));
 	}
 		break;
 	case 'T':
@@ -181,7 +189,19 @@ int parse_buffer() {
 		uint16_t boost;
 		if (next_arg_unsigned(&boost)) break;
 
-		printf("T%d\n", bd_set_treble_boost(&hi2c1, boost));
+		printf("T%d\n", (ui_state.tboost = bd_set_treble_boost(&hi2c1, boost)));
+	}
+		break;
+	case '?':
+	{
+		// return the system state
+		printf("M%d\n", is_muted());
+		printf("S%d\n", is_shorted());
+		printf("C%d\n", get_input());
+		printf("B%d\n", ui_state.bboost);
+		printf("T%d\n", ui_state.tboost);
+		printf("L%d\n", ui_state.latt);
+		printf("R%d\n", ui_state.ratt);
 	}
 		break;
 	default: