diff --git a/.gitignore b/.gitignore
index 093e781..fb04b32 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,6 @@
 *.b#*
 *.s#*
-gerber/
+gerbers/
 .DS_Store
 partslist*
 *farnell*
diff --git a/software/apps/Motion/Motion0/Motion0.ino b/software/apps/Motion/Motion0/Motion0.ino
new file mode 100644
index 0000000..8677ff3
--- /dev/null
+++ b/software/apps/Motion/Motion0/Motion0.ino
@@ -0,0 +1,55 @@
+#include <Motion.h>
+
+/*
+
+Two motion objects are available from the MMM Motions library
+(1) MotionA
+(2) MotionB
+
+MOTION {
+    MOTIONA ,
+    MOTIONB1
+};
+
+Each objects needs intialisation with a specific input 
+from which ADC reading will be performed.
+
+Users may choose and identify inputs aa INPUT[A0, ... ,A7].
+ex: MotionA.init(INPOUTA5);
+
+INPUT {
+    INPUTA0,
+    INPUTA1,
+    INPUTA2,
+    INPUTA3,
+    INPUTA4,
+    INPUTA5,
+    INPUTA6,
+    INPUTA7      
+}
+
+All calculation of physics (position, velocity and acceleration) 
+are computed internally usign interrupts and timers. To access
+such information, user may call getPosition(), getVelocity() 
+and getAcceleration() respectively on a initialised Motion object.
+
+int getPosition();
+float getVelocity();
+float getAcceleration();
+
+*/
+
+void setup() {
+  MotionA.init(INPUTA0);
+  Serial.begin(9600);
+}
+
+void loop() {
+  Serial.print("position: "); Serial.println(MotionA.getPosition());
+  Serial.print("velocity: "); Serial.println(MotionA.getVelocity());
+  Serial.print("accel: "); Serial.println(MotionA.getAcceleration());
+  Serial.println("-------");
+  delay(100);
+}
+
+
diff --git a/software/lib/MMM/Motion.cpp b/software/lib/MMM/Motion.cpp
index a587da9..7baccdb 100644
--- a/software/lib/MMM/Motion.cpp
+++ b/software/lib/MMM/Motion.cpp
@@ -37,19 +37,24 @@ Motion MotionB(MOTIONA);
 uint8_t lb;
 uint8_t hb;
 int     x, xx; 
-float   T = N * 0.004f; // 4ms
+float   T = N * 0.004f;             // 4ms (see TCNT1)
 float   v;
 
+float MAX_POS = 1023;
+float MAX_VEL = MAX_POS / T;
+float MAX_ACC = MAX_VEL / T;
+
 
 Motion::Motion(MOTION m){
     _m = m;
     _i = false;
+    _fcb = NULL;
 };
 
 void Motion::init(INPUT sensor)
 {        
     if(!motion_reg_init){
-        TCNT1 = 1000; //4 ms 
+        TCNT1 = 1000;               //4 ms (TCNT1)
         TIMSK1 = (1 << TOIE1);
         motion_reg_init = true;    
     }
@@ -57,11 +62,6 @@ void Motion::init(INPUT sensor)
     _s = sensor;
 }
 
-void Motion::updatePhysics() 
-{
-    
-}
-
 int Motion::getPosition() {
     return _x;
 }
@@ -74,6 +74,11 @@ float Motion::getAcceleration() {
     return _a;
 }
 
+void Motion::set_force_callback(force_callback fcb, PHY physics) {
+    _fcb = fcb;
+    _fcb_phy = physics;
+}
+
 
 // clocked at 4ms period
 ISR(TIMER1_OVF_vect) {
diff --git a/software/lib/MMM/Motion.h b/software/lib/MMM/Motion.h
index 8ffeb0d..b066034 100644
--- a/software/lib/MMM/Motion.h
+++ b/software/lib/MMM/Motion.h
@@ -25,6 +25,8 @@
 
 #define N 10
 
+typedef float (*force_callback)(float position);
+
 enum MOTION {
     MOTIONA = 0,
     MOTIONB = 1
@@ -41,6 +43,12 @@ enum INPUT {
     INPUTA7 = 0x0111    
 };
 
+enum PHY {
+    POSITION = 0,
+    VELOCITY = 1,
+    ACCELERATION = 2
+};
+
 
 class Motion {
     
@@ -53,12 +61,13 @@ public:
     float getVelocity();
     float getAcceleration();
     
-    void updatePhysics();
+    void set_force_callback(force_callback fcb, PHY physics);
     
     
     // raw position vector
     int _xv[N];
     int _ix;    
+    
     int _x;    
     float _v;
     float _a;
@@ -67,6 +76,8 @@ public:
     INPUT  _s;
     bool   _i;
     
+    force_callback _fcb;
+    PHY            _fcb_phy;
 };
 
 extern Motion MotionA;