Index: firmware/App/Services/PIControllers.c
===================================================================
diff -u
--- firmware/App/Services/PIControllers.c	(revision 0)
+++ firmware/App/Services/PIControllers.c	(revision 83c8cecd53d54b4ebfdb6d136701e9522ed99cf2)
@@ -0,0 +1,181 @@
+/**************************************************************************
+ *
+ *  Copyright (c) 2019-2019 Diality Inc. - All Rights Reserved.
+ *
+ *  THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
+ *  WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
+ *
+ *  @file PIControllers.c
+ *
+ *  @date 18-Dec-2019
+ *  @author L. Baloa
+ *
+ *  @brief PIControllers service module.  Creates a digital PI to be used as
+ *  control loops
+ *
+ **************************************************************************/
+#include "PIControllers.h"
+
+// ********** private definitions **********
+
+typedef struct {
+    // -- PI's parameters --
+    F32                 Kp;                         // Proportional Value
+    F32                 Ki;                         // Integral Value
+    S32                 uMax;                       // Maximum control signal
+    S32                 uMin;                       // Minimum control signal
+    // -- PI's signals --
+    BOOL                firstIteration;             // Mark true for the first iteration
+    S32                 referenceSignal;            // reference signal
+    S32                 measuredSignal;             // measured signal
+    S32                 errorSignal;                // reference - measured signal
+    S32                 errorSumBeforeWindUp;       // error signal before windup correction
+    S32                 errorSum;                   // error integral after windup correction
+    S32                 controlSignal;              // actual control signal
+} PI_CONTROLLER_T;
+
+// PI Controllers -- definition
+
+static PI_CONTROLLER_T piControllers[ NUM_OF_PI_CONTROLLERS_IDS ] =
+{
+
+                    { /*Kp*/ 1.0, /*Ki*/ 1.0, /*uMax*/ 90, /*uMin*/ 0}  // PI_CONTROLLER_ID_LOAD_CELL = 0
+};
+
+static PI_CONTROLLER_T* m_controller;
+
+#define SET_CONTROLLER(id)  (m_controller = &piControllers[id])
+
+/*************************************************************************
+ * @brief initializeController
+ * Initialize controller before operation. Make sure to run it before
+ * first call to runController function.
+ *
+ * @param controllerID - ID filter number
+ * @param initialControlSignal - Value of the output on the first iteration
+ *
+ * @return none
+ *************************************************************************/
+void initializeController(PI_CONTROLLER_ID_T controllerID, U16 initialControlSignal)
+{
+
+    SET_CONTROLLER(controllerID);
+
+    m_controller->firstIteration = TRUE;
+
+    m_controller->controlSignal = RANGE(initialControlSignal,
+                                        m_controller->uMin,
+                                        m_controller->uMax);
+}
+
+/*************************************************************************
+ * @brief runController
+ * Call this function whenever a new measured signal sampled is acquired.
+ *
+ * @param controllerID - ID filter number
+ * @param referenceSignal - reference signal value
+ * @param measuredSignal - latest measured sample
+ *
+ * @return value of the control signal
+ *************************************************************************/
+S32 runController(PI_CONTROLLER_ID_T controllerID, S32 referenceSignal, S32 measuredSignal)
+{
+
+    SET_CONTROLLER(controllerID);
+
+    m_controller->referenceSignal = referenceSignal;
+    m_controller->measuredSignal = measuredSignal;
+    m_controller->errorSignal = referenceSignal - measuredSignal;
+    m_controller->errorSum += m_controller->errorSignal;
+    m_controller->errorSumBeforeWindUp = m_controller->errorSum;
+
+    if( !m_controller->firstIteration || ( m_controller->controlSignal == 0 ) )
+    {
+        S32 controlSignalBeforeWindup = (S32) (m_controller->Kp * m_controller->errorSignal +
+                                         m_controller->Ki * m_controller->errorSum);
+
+        m_controller->controlSignal = RANGE(controlSignalBeforeWindup, m_controller->uMin, m_controller->uMax);
+
+        S32 error = m_controller->controlSignal - controlSignalBeforeWindup;
+
+        // Anti-wind up logic
+
+        if ( error != 0 )
+        {
+            // We have hit a max or min, need to compensate
+            m_controller->errorSum -= (S32)(error/m_controller->Ki);
+        }
+    }
+    else
+    {
+        m_controller->errorSum = (S32) ((m_controller->controlSignal - m_controller->Kp*m_controller->errorSignal)/(m_controller->Ki));
+    }
+
+
+    return m_controller->controlSignal;
+}
+
+/*************************************************************************
+ * @brief getController
+ * Returns the latest requested signal sample.
+ *
+ * @param controllerID - ID filter number
+ * @param signalID -  signal sample ID request
+ *
+ * @return latest sample requested
+ *************************************************************************/
+S32 getControllerSignals(PI_CONTROLLER_ID_T controllerID, PI_CONTROLLER_SIGNALS_ID signalID)
+{
+
+    SET_CONTROLLER(controllerID);
+
+    S32 output;
+
+    switch(signalID) {
+
+        case CONTROLLER_SIGNAL_REFERENCE:
+            output = m_controller->referenceSignal;
+            break;
+
+        case CONTROLLER_SIGNAL_MEASURED:
+            output = m_controller->measuredSignal;
+            break;
+
+        case CONTROLLER_SIGNAL_ERROR:
+            output = m_controller->errorSignal;
+            break;
+
+        case CONTROLLER_SIGNAL_ERROR_SUM:
+            output = m_controller->errorSumBeforeWindUp;
+            break;
+
+        case CONTROLLER_SIGNAL_ERROR_SUM_AFTER_WINDUP:
+            output = m_controller->errorSum;
+            break;
+
+        case CONTROLLER_SIGNAL_PROPORTIONAL_OUTPUT:
+            output = (S32)(m_controller->Kp * m_controller->errorSignal);
+            break;
+
+        case CONTROLLER_SIGNAL_INTEGRAL_OUTPUT:
+            output = (S32)(m_controller->Ki * m_controller->errorSum);
+            break;
+
+        case CONTROLLER_SIGNAL_CONTROL_BEFORE_WINDUP:
+            output = (S32)(m_controller->Ki * m_controller->errorSumBeforeWindUp +
+                           m_controller->Kp * m_controller->errorSignal);
+            break;
+
+        case CONTROLLER_SIGNAL_CONTROL:
+            output = (S32)(m_controller->Ki * m_controller->errorSum +
+                           m_controller->Kp * m_controller->errorSignal);
+            break;
+
+        default:
+            output = 0;
+            break;
+    } // end of switch
+
+    return output;
+}
+
Index: firmware/App/Services/PIControllers.h
===================================================================
diff -u
--- firmware/App/Services/PIControllers.h	(revision 0)
+++ firmware/App/Services/PIControllers.h	(revision 83c8cecd53d54b4ebfdb6d136701e9522ed99cf2)
@@ -0,0 +1,54 @@
+/**************************************************************************
+ *
+ *  Copyright (c) 2019-2019 Diality Inc. - All Rights Reserved.
+ *
+ *  THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
+ *  WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
+ *
+ *  @file PIControllers.h
+ *
+ *  @date 12-Dec-2019
+ *  @author L. Baloa
+ *
+ *  @brief Header file for the PI controllers service (PIControllers.c).
+ *
+ **************************************************************************/
+
+#ifndef __PICONTROLLERS_H__
+#define __PICONTROLLERS_H__
+
+
+#include "Common.h"
+
+typedef enum ControllerList
+{
+    PI_CONTROLLER_ID_LOAD_CELL = 0,
+    NUM_OF_PI_CONTROLLERS_IDS
+} PI_CONTROLLER_ID_T;
+
+typedef enum ControllerSignals
+{
+    CONTROLLER_SIGNAL_REFERENCE = 0,
+    CONTROLLER_SIGNAL_MEASURED,
+    CONTROLLER_SIGNAL_ERROR,
+    CONTROLLER_SIGNAL_ERROR_SUM,
+    CONTROLLER_SIGNAL_ERROR_SUM_AFTER_WINDUP,
+    CONTROLLER_SIGNAL_PROPORTIONAL_OUTPUT,
+    CONTROLLER_SIGNAL_INTEGRAL_OUTPUT,
+    CONTROLLER_SIGNAL_CONTROL_BEFORE_WINDUP,
+    CONTROLLER_SIGNAL_CONTROL,
+    NUM_OF_CONTROLLER_SIGNAL
+} PI_CONTROLLER_SIGNALS_ID;
+
+
+
+
+// ********** public function prototypes **********
+
+void initializeController(PI_CONTROLLER_ID_T controllerID, U16 initialControlSignal);
+S32 runController(PI_CONTROLLER_ID_T controllerID, S32 referenceSignal, S32 measuredSignal);
+S32 getControllerSignals(PI_CONTROLLER_ID_T controllerID, PI_CONTROLLER_SIGNALS_ID signalID);
+
+
+
+#endif