diff --git a/PercTeacher/Sources/ApplicationJava/SerialCommands.java b/PercTeacher/Sources/ApplicationJava/SerialCommands.java
index 882a8ed..96e850e 100644
--- a/PercTeacher/Sources/ApplicationJava/SerialCommands.java
+++ b/PercTeacher/Sources/ApplicationJava/SerialCommands.java
@@ -2,9 +2,19 @@
 public class SerialCommands {
 	public static void sendDeltas(SerialCom serialCom, int deltaLeft, int deltaRight) {
 		byte dataL1 = (byte) ((deltaLeft & 0xFF00) >> 8);
+		if(deltaLeft < 0)
+			dataL1 &= 0x7F;
+		else
+			dataL1 |= 0x80;
 		byte dataL2 = (byte) (deltaLeft & 0xFF);
+
 		byte dataR1 = (byte) ((deltaRight & 0xFF00) >> 8);
+		if(deltaRight < 0)
+			dataR1 &= 0x7F;
+		else
+			dataR1 |= 0x80;
 		byte dataR2 = (byte) (deltaRight & 0xFF);
+
 		byte[] data = new byte[] {dataL1, dataL2, dataR1, dataR2};
 		serialCom.send(data);
 		
diff --git a/tests/atmega2560/servoAndStepperControl/servoAndStepperControl.c b/tests/atmega2560/servoAndStepperControl/servoAndStepperControl.c
index 6a4bf4b..2f764f1 100644
--- a/tests/atmega2560/servoAndStepperControl/servoAndStepperControl.c
+++ b/tests/atmega2560/servoAndStepperControl/servoAndStepperControl.c
@@ -3,26 +3,26 @@
 
 int main(void){
 	// pin 13
-	DDRB = 0xC0;
+	DDRB = 0x60;
 
-	PORTB |= 0x40; // forward
+	PORTB |= 0x20; // forward
 	int i = 0;
 	int sens = 0;
 	while(1){
 		// step
-		PORTB |= 0x80;
-		_delay_ms(5);
-		PORTB &= 0x7F;
-		_delay_ms(5);
+		PORTB |= 0x40;
+		_delay_ms(2);
+		PORTB &= 0xBF;
+		_delay_ms(2);
 		// dir
 		i++;
-		if(i > 200){
+		if(i > 1000){
 			i = 0;
 			sens = 1 - sens;
 			if(sens == 0)
-				PORTB |= 0x40; // forward
+				PORTB |= 0x20; // forward
 			else
-				PORTB &= 0xBF; // backward
+				PORTB &= 0xDF; // backward
 		}
 	}
 	return 0;
--
libgit2 0.21.2