diff --git a/README.md b/README.md
index 6ddd72f..b2eff59 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,8 @@
 Line Follower Resources
 =======================
 
-
 Resources for the Line Follower Competition, Winter 2015
+
+There are two versions of the line follower algorithm in this repo:
+- A simple control algorithm with two sensors that just switches direction ([code](https://github.com/byu-mechatronics/line-follower/blob/master/line_follower_bang.ino)).
+- A more advanced control system with a PID loop ([code](https://github.com/byu-mechatronics/line-follower/blob/master/line_follower_one.ino)).
diff --git a/line_follower_bang.ino b/line_follower_bang.ino
new file mode 100644
index 0000000..a85eacb
--- /dev/null
+++ b/line_follower_bang.ino
@@ -0,0 +1,137 @@
+/*
+
+Line Follower control using Bang-Bang algorithm
+Written 3/2/15 by Walter Coe, BYU Mechatronics Club
+For more explaination on Bang-Bang control, see here...
+http://en.wikipedia.org/wiki/Bang%E2%80%93bang_control
+
+Ecplaination for use of this code...
+    Use two sensors positioned so that they straddle the line to be followed
+    The assumed sensor is a photo-transistor sensor (i.e. QRD1114 or similar)
+    There must be a threshold determined by the user, i.e. the value of variable 's_thresh'
+        Builder must verify that the sensor theshold is not met by both sensors simultaniously
+
+
+*/
+
+//Define Sensor Pins
+//A0 is on the left
+//A1 is on the right
+const int s0 = A0;
+const int s1 = A1;
+
+
+//Motor Constraints
+//Set motor_low to lowest duty cycle % that turns the motor
+const float motor_low = .25;
+const float motor_avg = .75;
+
+//Define motor drive pins
+//Must be chosen for your wiring, connect these pins to switches(MOSFET of BJT)
+const int motor_L = 3;
+const int motor_R = 4;
+
+//Define the sensor threshold
+const float s_thresh = .25;
+
+//Variable used to to store sensor data
+int turn;
+
+//Holds time of last line detection
+//Used to avoid runaway robots
+long t_last;
+const int t_thresh = 10000;
+const int pause = 10000;
+
+//----------------------------------------------------------------------------------------------------------------------------
+
+void setup()
+{
+  //Setup serial terminal printing
+  Serial.begin(9600);
+  
+  //Setup the pins that will drive the switches (MOSFET or BJT)
+  pinMode(motor_L, OUTPUT);
+  pinMode(motor_R, OUTPUT);
+
+ //Initialize
+  turn = 0;
+  
+  //Initialize
+  t_last = millis();
+}
+
+void loop()
+{
+  //Check for the line
+  turn = line_check(s0, s1);
+  
+  //Based on sensor reading, turn or go straight
+  drive_motor(turn, motor_L, motor_R, motor_low, motor_avg);
+  
+  //If you saw the line, reset timer
+  if( turn != 0)
+  {
+   t_last = millis(); 
+  }
+  
+  //If the line hasn't been seen, stop for some time
+  if( millis() - t_last > t_thresh )
+    {
+     delay(pause); 
+    }
+    
+}
+
+//----------------------------------------------------------------------------------------------------------------------------
+
+int line_check(int s0, int s1)
+{
+   
+  //Line seen by left sensor
+   if(analogRead(s0) <= s_thresh)
+   {
+     return(0); 
+   }
+   
+   //Line seen by right sensor
+   else if(analogRead(s1) <= s_thresh)
+   {
+     return(1);
+   }
+   
+   //Line not seen
+   else
+   {
+     return(-1); 
+   }
+  
+}
+
+void drive_motor(int turn_dir, int motor_L, int motor_R, float motor_low, float motor_avg)
+{
+  //Turn right
+  if( turn_dir == 0 )
+  {
+     analogWrite(motor_L, motor_avg);
+     analogWrite(motor_R, motor_low); 
+  }
+  
+  //Turn left
+  else if( turn_dir == 1)
+  {
+     analogWrite(motor_L, motor_low);
+     analogWrite(motor_R, motor_avg); 
+  }
+  
+  //Go straight
+  else
+  {
+     analogWrite(motor_L, motor_avg);
+     analogWrite(motor_R, motor_avg);
+  }
+  
+}
+
+
+
diff --git a/line_follower_one.ino b/line_follower_one.ino
index 4b2b035..1f2f64e 100644
--- a/line_follower_one.ino
+++ b/line_follower_one.ino
@@ -1,22 +1,15 @@
 /*
-
 Line Follower utilizing a PID algorithm
 Written 2/28/15 by Walter Coe, BYU Mechatronics Club
 A great explanation of PID can be found here...
 http://www.pc-control.co.uk/feedback_control.htm
-
-
  - -----------> +
-
 |-|     s      |-|
 | |------------| |
 |-|    |||     |-|
        |||
        |||
-
-
   Assumptions for using this code....
-
   Using one photo-transistor sensor (i.e. QRD1114 or similar)
   The sensor will need to be tuned, by choosing the pull-up resistor
     A bigger resistor will make for a faster transition between 0-5v output, but will result in a narrow detection range
@@ -29,13 +22,8 @@ http://www.pc-control.co.uk/feedback_control.htm
   2) Connect power (can be done with a switch)
   3) Arduino will wait 2 seconds before starting to follow the line
   4) If the Arduino moves to fast to react to the line, you can slow the speed by lowering the motor_avg value
-
-
-
 sensor reads light (higher value output from 'pos' equation) when it needs to turn left
 sensor reads dark (lower value output from 'pos' equation) where it needs to turn right
-
-
 */
 
 //Define Sensor Pins
@@ -146,7 +134,7 @@ void loop()
       
       //To far left when negative
       //To far right when positive
-      differentiator = (2*tau - Ts)/(2*tau+Ts)*differentiator + (2/(2*tau+Ts))*(error_d1 - error);
+      differentiator = (2*tau - Ts)/(2*tau+Ts)*differentiator + (2/(2*tau+Ts))*(posError_d1 - posError);
       
         
       //If Integrating is safe      
@@ -257,4 +245,4 @@ void drive_motor(float PID, float PID_max, float pwm_min, float pwm_avg, int mot
  Serial.println(PWM_L);
  Serial.println(PWM_R);
     
-}
+}