diff --git a/examples/audio-trough.pd b/examples/audio-trough.pd
deleted file mode 100644
index 29ce98b..0000000
--- a/examples/audio-trough.pd
+++ /dev/null
@@ -1,52 +0,0 @@
-#N canvas 2220 331 802 519 12;
-#X obj 112 43 adc~ 1 2 3 4 5 6, f 47;
-#X obj 113 199 dac~ 1 2 3 4 5 6, f 47;
-#X obj 112 127 *~ 1;
-#X obj 137 94 r K1;
-#X obj 178 126 *~ 1;
-#X obj 242 128 *~ 1;
-#X obj 308 127 *~ 1;
-#X obj 372 127 *~ 1;
-#X obj 438 126 *~ 1;
-#X obj 203 93 r K2;
-#X obj 267 93 r K3;
-#X obj 333 94 r K4;
-#X obj 397 93 r K5;
-#X obj 463 93 r K6;
-#X obj 290 416 print toVCV;
-#X msg 267 278 L3 \$1 0 0;
-#X msg 333 310 L4 \$1 0 0;
-#X msg 463 311 L6 \$1 0 0;
-#X msg 136 277 L1 \$1 0 0;
-#X msg 203 309 L2 \$1 0 0;
-#X msg 397 280 L5 \$1 0 0;
-#X connect 0 0 2 0;
-#X connect 0 1 4 0;
-#X connect 0 2 5 0;
-#X connect 0 3 6 0;
-#X connect 0 4 7 0;
-#X connect 0 5 8 0;
-#X connect 2 0 1 0;
-#X connect 3 0 2 1;
-#X connect 3 0 18 0;
-#X connect 4 0 1 1;
-#X connect 5 0 1 2;
-#X connect 6 0 1 3;
-#X connect 7 0 1 4;
-#X connect 8 0 1 5;
-#X connect 9 0 4 1;
-#X connect 9 0 19 0;
-#X connect 10 0 5 1;
-#X connect 10 0 15 0;
-#X connect 11 0 6 1;
-#X connect 11 0 16 0;
-#X connect 12 0 7 1;
-#X connect 12 0 20 0;
-#X connect 13 0 8 1;
-#X connect 13 0 17 0;
-#X connect 15 0 14 0;
-#X connect 16 0 14 0;
-#X connect 17 0 14 0;
-#X connect 18 0 14 0;
-#X connect 19 0 14 0;
-#X connect 20 0 14 0;
diff --git a/examples/gain.pd b/examples/gain.pd
new file mode 100644
index 0000000..ab6906d
--- /dev/null
+++ b/examples/gain.pd
@@ -0,0 +1,106 @@
+#N canvas 2220 331 805 580 12;
+#X obj 112 43 adc~ 1 2 3 4 5 6, f 47;
+#X obj 113 281 dac~ 1 2 3 4 5 6, f 47;
+#X obj 112 127 *~ 1;
+#X obj 137 94 r K1;
+#X obj 178 126 *~ 1;
+#X obj 242 128 *~ 1;
+#X obj 308 127 *~ 1;
+#X obj 372 127 *~ 1;
+#X obj 438 126 *~ 1;
+#X obj 203 93 r K2;
+#X obj 267 93 r K3;
+#X obj 333 94 r K4;
+#X obj 397 93 r K5;
+#X obj 463 93 r K6;
+#X obj 290 502 print toVCV;
+#X msg 267 315 L3 \$1 0 0;
+#X msg 333 347 L4 \$1 0 0;
+#X msg 463 348 L6 \$1 0 0;
+#X msg 136 314 L1 \$1 0 0;
+#X msg 203 346 L2 \$1 0 0;
+#X msg 397 317 L5 \$1 0 0;
+#X obj 112 230 *~ 1;
+#X obj 178 229 *~ 1;
+#X obj 242 231 *~ 1;
+#X obj 308 230 *~ 1;
+#X obj 372 230 *~ 1;
+#X obj 438 229 *~ 1;
+#X obj 147 158 r S1;
+#X obj 213 157 r S2;
+#X obj 277 157 r S3;
+#X obj 343 158 r S4;
+#X obj 407 157 r S5;
+#X obj 473 158 r S6;
+#X obj 473 197 - 1;
+#X obj 407 196 - 1;
+#X obj 343 194 - 1;
+#X obj 277 195 - 1;
+#X obj 213 196 - 1;
+#X obj 147 195 - 1;
+#X msg 146 404 S1 \$1 0 0;
+#X msg 213 436 S2 \$1 0 0;
+#X msg 277 405 S3 \$1 0 0;
+#X msg 343 438 S4 \$1 0 0;
+#X msg 407 407 S5 \$1 0 0;
+#X msg 473 437 S6 \$1 0 0;
+#X connect 0 0 2 0;
+#X connect 0 1 4 0;
+#X connect 0 2 5 0;
+#X connect 0 3 6 0;
+#X connect 0 4 7 0;
+#X connect 0 5 8 0;
+#X connect 2 0 21 0;
+#X connect 3 0 2 1;
+#X connect 3 0 18 0;
+#X connect 4 0 22 0;
+#X connect 5 0 23 0;
+#X connect 6 0 24 0;
+#X connect 7 0 25 0;
+#X connect 8 0 26 0;
+#X connect 9 0 4 1;
+#X connect 9 0 19 0;
+#X connect 10 0 5 1;
+#X connect 10 0 15 0;
+#X connect 11 0 6 1;
+#X connect 11 0 16 0;
+#X connect 12 0 7 1;
+#X connect 12 0 20 0;
+#X connect 13 0 8 1;
+#X connect 13 0 17 0;
+#X connect 15 0 14 0;
+#X connect 16 0 14 0;
+#X connect 17 0 14 0;
+#X connect 18 0 14 0;
+#X connect 19 0 14 0;
+#X connect 20 0 14 0;
+#X connect 21 0 1 0;
+#X connect 22 0 1 1;
+#X connect 23 0 1 2;
+#X connect 24 0 1 3;
+#X connect 25 0 1 4;
+#X connect 26 0 1 5;
+#X connect 27 0 38 0;
+#X connect 27 0 39 0;
+#X connect 28 0 37 0;
+#X connect 28 0 40 0;
+#X connect 29 0 36 0;
+#X connect 29 0 41 0;
+#X connect 30 0 35 0;
+#X connect 30 0 42 0;
+#X connect 31 0 34 0;
+#X connect 31 0 43 0;
+#X connect 32 0 33 0;
+#X connect 32 0 44 0;
+#X connect 33 0 26 1;
+#X connect 34 0 25 1;
+#X connect 35 0 24 1;
+#X connect 36 0 23 1;
+#X connect 37 0 22 1;
+#X connect 38 0 21 1;
+#X connect 39 0 14 0;
+#X connect 40 0 14 0;
+#X connect 41 0 14 0;
+#X connect 42 0 14 0;
+#X connect 43 0 14 0;
+#X connect 44 0 14 0;
diff --git a/src/LibPDEngine.cpp b/src/LibPDEngine.cpp
index 212a37a..ec06e9b 100644
--- a/src/LibPDEngine.cpp
+++ b/src/LibPDEngine.cpp
@@ -9,7 +9,8 @@ using namespace rack;
 // there is no multi-instance support for receiving messages from libpd
 // for now, received values for the prototype gui will be stored in global variables
 
-float g_leds[NUM_ROWS][3];
+float g_lights[NUM_ROWS][3] = {};
+float g_switchLights[NUM_ROWS][3] = {};
 
 std::vector<std::string> split (const std::string &s, char delim) {
     std::vector<std::string> result;
@@ -25,7 +26,6 @@ std::vector<std::string> split (const std::string &s, char delim) {
 
 
 
-
 struct LibPDEngine : ScriptEngine {
 
 	~LibPDEngine() {
@@ -33,23 +33,25 @@ struct LibPDEngine : ScriptEngine {
 
 	}
 
-	static void receiveLEDs(const char *s);
-
+	void sendInitialStates(const ProcessBlock* block);
+	static void receiveLights(const char *s);
 	bool knobChanged(const float* knobs, int idx);
-
-	bool switchChanged(const float* knobs, int idx);
+	bool switchChanged(const bool* knobs, int idx);
+	void sendKnob(const int idx, const float value);
+	void sendSwitch(const int idx, const bool value);
 
 	t_pdinstance *_lpd;
 	int _pd_block_size = 64;
   	int _sampleRate = 0;
   	int _ticks = 0;
+  	bool _init = true;
   	
-  	float _old_knobs[NUM_ROWS];
-  	bool  _old_switches[NUM_ROWS];
-  	float _output[BUFFERSIZE];
-  	float _input[BUFFERSIZE];//  = (float*)malloc(1024*2*sizeof(float));
-  	const static std::map<std::string, int> _led_map;
-
+  	float _old_knobs[NUM_ROWS] = {};
+  	bool  _old_switches[NUM_ROWS] = {};
+  	float _output[BUFFERSIZE] = {};
+  	float _input[BUFFERSIZE] = {};//  = (float*)malloc(1024*2*sizeof(float));
+  	const static std::map<std::string, int> _light_map;
+  	const static std::map<std::string, int> _switchLight_map;
 
 	std::string getEngineName() override {
 		return "Pure Data";
@@ -65,12 +67,8 @@ struct LibPDEngine : ScriptEngine {
 	  	_lpd = libpd_new_instance();
 
 	  	libpd_set_printhook((t_libpd_printhook)libpd_print_concatenator);
-		libpd_set_concatenated_printhook( receiveLEDs );
-	  	//libpd_set_printhook(receiveLEDs);
-	  	//libpd_bind("L2");
-	  	//libpd_bind("foo");
-	  	//libpd_set_listhook(receiveList);
-	  	//libpd_set_messagehook(receiveMessage);
+		libpd_set_concatenated_printhook( receiveLights );
+
 
 	 	if(libpd_num_instances()>2)
 		{
@@ -89,6 +87,8 @@ struct LibPDEngine : ScriptEngine {
 	    std::string name = string::filename(path);
 	    std::string dir  = string::directory(path);
 	  	libpd_openfile(name.c_str(), dir.c_str());
+
+	  	sendInitialStates(block);
 	  
 		return 0;
 	}
@@ -110,22 +110,25 @@ struct LibPDEngine : ScriptEngine {
 		// knobs
 		for (int i=0; i<NUM_ROWS; i++){
 			if( knobChanged(block->knobs, i) ){
-				std::string knob = "K"+std::to_string(i+1);
-				libpd_float(knob.c_str(), block->knobs[i]);
+				sendKnob(i, block->knobs[i]);
 			}
 		}
-		// leds
-		//display(std::to_string(g_leds[0]));
+		// lights
+		for(int i=0; i<NUM_ROWS; i++){
+			block->lights[i][0] = g_lights[i][0];
+			block->lights[i][1] = g_lights[i][1];
+			block->lights[i][2] = g_lights[i][2];
+		}
+		// switch lights
 		for(int i=0; i<NUM_ROWS; i++){
-			block->lights[i][0] = g_leds[i][0];
-			block->lights[i][1] = g_leds[i][1];
-			block->lights[i][2] = g_leds[i][2];
+			block->switchLights[i][0] = g_switchLights[i][0];
+			block->switchLights[i][1] = g_switchLights[i][1];
+			block->switchLights[i][2] = g_switchLights[i][2];
 		}
 		// switches
 		for(int i=0; i<NUM_ROWS; i++){
 			if( switchChanged(block->switches, i) ){
-				std::string sw = "S"+std::to_string(i+1);
-				libpd_float(sw.c_str(), block->switches[i]);
+				sendSwitch(i, block->switches[i]);
 			}
 		}
 		// process samples in libpd
@@ -150,29 +153,48 @@ static void constructor() {
 }
 
 
-void LibPDEngine::receiveLEDs(const char *s) {
+void LibPDEngine::receiveLights(const char *s) {
 	std::string str = std::string(s);
 	std::vector<std::string> atoms = split (str, ' ');
 
 	if(atoms[0]=="toVCV:"){
-		// led list
-		bool led_is_valid = true;
-		int led_idx = -1;
+		// light list
+		bool light_is_valid = true;
+		int light_idx = -1;
 		try {
-				led_idx = _led_map.at(atoms[1]);      // map::at throws an out-of-range
+				light_idx = _light_map.at(atoms[1]);      // map::at throws an out-of-range
 			}
 		catch (const std::out_of_range& oor) {
-			led_is_valid = false;
+			light_is_valid = false;
 			//display("Warning:"+atoms[1]+" not found!");
 		}
 		//std::cout << v[1] << ", " << g_led_map[v[1]] << std::endl;
-		if(led_is_valid && atoms.size()==5){
-			g_leds[led_idx][0] = stof(atoms[2]); // red
-			g_leds[led_idx][1] = stof(atoms[3]); // green
-			g_leds[led_idx][2] = stof(atoms[4]); // blue
+		if(light_is_valid && atoms.size()==5){
+			g_lights[light_idx][0] = stof(atoms[2]); // red
+			g_lights[light_idx][1] = stof(atoms[3]); // green
+			g_lights[light_idx][2] = stof(atoms[4]); // blue
 		}
 		else {
-			
+			// error
+		}
+
+		bool switchLight_is_valid = true;
+		int switchLight_idx = -1;
+		try {
+				switchLight_idx = _switchLight_map.at(atoms[1]);      // map::at throws an out-of-range
+			}
+		catch (const std::out_of_range& oor) {
+			switchLight_is_valid = false;
+			//display("Warning:"+atoms[1]+" not found!");
+		}
+		//std::cout << v[1] << ", " << g_led_map[v[1]] << std::endl;
+		if(switchLight_is_valid && atoms.size()==5){
+			g_switchLights[switchLight_idx][0] = stof(atoms[2]); // red
+			g_switchLights[switchLight_idx][1] = stof(atoms[3]); // green
+			g_switchLights[switchLight_idx][2] = stof(atoms[4]); // blue
+		}
+		else {
+			// error
 		}
 	}
 	else { 
@@ -189,7 +211,7 @@ bool LibPDEngine::knobChanged(const float* knobs, int i){
 	return knob_changed;
 }
 
-bool LibPDEngine::switchChanged(const float* switches, int i){
+bool LibPDEngine::switchChanged(const bool* switches, int i){
 	bool switch_changed = false;
 	if (_old_switches[i] != switches[i]){
 		switch_changed = true;
@@ -198,11 +220,38 @@ bool LibPDEngine::switchChanged(const float* switches, int i){
 	return switch_changed;
 }
 
-const std::map<std::string, int> LibPDEngine::_led_map{
+const std::map<std::string, int> LibPDEngine::_light_map{
 	{ "L1", 0 },
 	{ "L2", 1 },
 	{ "L3", 2 },
 	{ "L4", 3 },
 	{ "L5", 4 },
  	{ "L6", 5 }
-};
\ No newline at end of file
+};
+
+const std::map<std::string, int> LibPDEngine::_switchLight_map{
+	{ "S1", 0 },
+	{ "S2", 1 },
+	{ "S3", 2 },
+	{ "S4", 3 },
+	{ "S5", 4 },
+ 	{ "S6", 5 }
+};
+
+void LibPDEngine::sendKnob(const int idx, const float value){
+	std::string knob = "K"+std::to_string(idx+1);
+	libpd_float(knob.c_str(), value);
+}
+
+void LibPDEngine::sendSwitch(const int idx, const bool value){
+	std::string sw = "S"+std::to_string(idx+1);
+	libpd_float(sw.c_str(), value);
+}
+
+void LibPDEngine::sendInitialStates(const ProcessBlock* block){
+	// knobs
+	for (int i=0; i<NUM_ROWS; i++){
+		sendKnob(i, block->knobs[i]);
+		sendSwitch(i, block->knobs[i]);
+	}
+}
\ No newline at end of file