Add hysteresis to joystick position X-Axis [WIP]

modified function
joystickPos_t joystick_evaluatePosition(float x, float y, joystickPos_t* prevPos)

because prevPos has to be stored http.cpp/hpp and joystick.cpp/hpp had
to be updated as well

TODO: add function without hysteresis again?
WIP this has to be tested

main/http.cpp

@@ -159,7 +159,7 @@ esp_err_t httpJoystick::receiveHttpData(httpd_req_t *req){
     //--- calculate angle ---
     data.angle = (atan(data.y/data.x) * 180) / 3.141;
     //--- evaluate position ---
-    data.position = joystick_evaluatePosition(data.x, data.y);
+    data.position = joystick_evaluatePosition(data.x, data.y, &stickPosPrevious);
 
     //log processed values
     ESP_LOGI(TAG, "processed values: x=%.3f  y=%.3f  radius=%.3f  angle=%.3f  pos=%s",

main/http.hpp

@@ -68,4 +68,6 @@ class httpJoystick{
             .radius = 0,
             .angle = 0
         };
+        //store last joystick position for position hysteresis
+        joystickPos_t stickPosPrevious = joystickPos_t::CENTER;
 };

main/joystick.cpp

@@ -93,7 +93,7 @@ joystickData_t evaluatedJoystick::getData() {
     data.angle = (atan(data.y/data.x) * 180) / 3.141;
 
     //define position
-    data.position = joystick_evaluatePosition(x, y);
+    data.position = joystick_evaluatePosition(x, y, &stickPosPrevious);
 
     return data;
 }
@@ -234,41 +234,67 @@ void joystick_scaleCoordinatesLinear(joystickData_t * data, float pointX, float
 //========= joystick_evaluatePosition =========
 //=============================================
 //function that defines and returns enum joystickPos from x and y coordinates
-joystickPos_t joystick_evaluatePosition(float x, float y){
+joystickPos_t joystick_evaluatePosition(float x, float y, joystickPos_t* prevPos){
+    joystickPos_t newPos;
     //define position
     //--- center ---
     if((fabs(x) == 0) && (fabs(y) == 0)){ 
-        return joystickPos_t::CENTER;
+        newPos = joystickPos_t::CENTER;
     }
     //--- x axis ---
     else if(fabs(y) == 0){
-        return joystickPos_t::X_AXIS;
+        newPos = joystickPos_t::X_AXIS;
     }
     //--- y axis ---
     else if(fabs(x) == 0){
-        return joystickPos_t::Y_AXIS;
+        newPos = joystickPos_t::Y_AXIS;
     }
     //--- top right ---
     else if(x > 0 && y > 0){
-        return joystickPos_t::TOP_RIGHT;
+        newPos = joystickPos_t::TOP_RIGHT;
     }
     //--- top left ---
     else if(x < 0 && y > 0){
-        return joystickPos_t::TOP_LEFT;
+        newPos = joystickPos_t::TOP_LEFT;
     }
     //--- bottom left ---
     else if(x < 0 && y < 0){
-        return joystickPos_t::BOTTOM_LEFT;
+        newPos = joystickPos_t::BOTTOM_LEFT;
     }
     //--- bottom right ---
     else if(x > 0 && y < 0){
-        return joystickPos_t::BOTTOM_RIGHT;
+        newPos = joystickPos_t::BOTTOM_RIGHT;
     }
     //--- other ---
     else {
-        return joystickPos_t::CENTER;
+        newPos = joystickPos_t::CENTER;
     }
 
+
+
+    //--- apply hysteresis on change from X-AXIS ---
+    //=> prevent frequent switching between X-AXIS and other positions
+    //otherwise this results in a very jerky motor action when in driving mode
+    float xAxisHyst = 0.2;
+
+    //change in position
+    if (newPos != *prevPos) {
+
+        //switched FROM x-axis to other position
+        if(*prevPos == joystickPos_t::X_AXIS) { //switch FROM X_AXIS
+
+            //verify coordinate changed more than hysteresis
+            if (fabs(y) < xAxisHyst) { //less offset than hysteresis
+                newPos = joystickPos_t::X_AXIS; //stay at X_AXIS position
+            } else { //switch is valid (enough change)
+                *prevPos = newPos;
+            }
+
+        } else { //switched to any other position
+                *prevPos = newPos;
+        }
+    }
+    return newPos;
 }
 
 

main/joystick.hpp

@@ -96,6 +96,8 @@ class evaluatedJoystick {
         joystickData_t data;
         float x;
         float y;
+        //store last joystick position for position hysteresis
+        joystickPos_t stickPosPrevious = joystickPos_t::CENTER;
 };
 
 
@@ -154,4 +156,5 @@ void joystick_scaleCoordinatesLinear(joystickData_t * data, float pointX, float
 //========= joystick_evaluatePosition =========
 //=============================================
 //function that defines and returns enum joystickPos from x and y coordinates
-joystickPos_t joystick_evaluatePosition(float x, float y);
+//joystickPos_t joystick_evaluatePosition(float x, float y);
+joystickPos_t joystick_evaluatePosition(float x, float y, joystickPos_t* prevPos);