Add linear scaling of stick coordinates

- joystick.hpp/cpp
  - add function joystick_scaleCoordinatesLinear(joystickData_t * data, float pointX, float pointY)
    that scales the coordinates with 2 different slopes before and
    after certain point

- control.cpp
  - scale coordinates linear with new function instead of exponential in JOYSTICK mode
  - scale coordinates linear with new function instead of exponential in HTTP mode

- config.cpp
  - adjust / decrease http joystick tolerances

Note: tested the armchair in http and joystick mode briefly and
      optimized the scaling point slightly

main/config.cpp

@@ -57,10 +57,10 @@ control_config_t configControl = {
 //----- httpJoystick config -----
 //-------------------------------
 httpJoystick_config_t configHttpJoystickMain{
-    .toleranceZeroX_Per = 3,  //percentage around joystick axis the coordinate snaps to 0
-    .toleranceZeroY_Per = 10,
+    .toleranceZeroX_Per = 1,  //percentage around joystick axis the coordinate snaps to 0
+    .toleranceZeroY_Per = 6,
     .toleranceEndPer = 2,   //percentage before joystick end the coordinate snaps to 1/-1
-    .timeoutMs = 3000       //time no new data was received before the motors get turned off
+    .timeoutMs = 2500       //time no new data was received before the motors get turned off
 };
 
 

main/control.cpp

@@ -70,8 +70,8 @@ void controlledArmchair::startHandleLoop() {
             case controlMode_t::JOYSTICK:
                 //get current joystick data with getData method of evaluatedJoystick
                 stickData = joystick.getData();
-                //additionaly scale coordinates exponentionally (more detail in slower area)
-                joystick_scaleCoordinatesExp(&stickData, 2); //TODO: add scaling exponent to config
+                //additionaly scale coordinates (more detail in slower area)
+                joystick_scaleCoordinatesLinear(&stickData, 0.6, 0.35); //TODO: add scaling parameters to config
                 //generate motor commands
                 commands = joystick_generateCommandsDriving(stickData);
                 //TODO: pass pointer to joystick object to control class instead of accessing it directly globally
@@ -97,7 +97,7 @@ void controlledArmchair::startHandleLoop() {
                 //TODO: as described above, when changing modes it might delay a few seconds for the change to apply
                 stickData = httpJoystickMain_l->getData();
                 //scale coordinates additionally (more detail in slower area)
-                joystick_scaleCoordinatesExp(&stickData, 2); //TODO: add scaling exponent to config
+                joystick_scaleCoordinatesLinear(&stickData, 0.6, 0.4); //TODO: add scaling parameters to config
                 ESP_LOGD(TAG, "generating commands from x=%.3f  y=%.3f  radius=%.3f  angle=%.3f", stickData.x, stickData.y, stickData.radius, stickData.angle);
                 //--- generate motor commands ---
                 //Note: timeout (no data received) is handled in getData method

main/joystick.cpp

@@ -190,6 +190,44 @@ void joystick_scaleCoordinatesExp(joystickData_t * data, float exponent){
 
 
 
+//==============================================
+//====== joystick_scaleCoordinatesLinear =======
+//==============================================
+//local function that scales value from -1-1 to -1-1 with two different slopes before and after a specified point
+//slope1: for value from 0 to pointX -> scale linear from  0 to pointY
+//slope2: for value from pointX to 1 -> scale linear from pointY to 1
+float scaleLinPoint(float value, float pointX, float pointY){
+    float result;
+    if (fabs(value) <= pointX) {
+        //--- scale on line from 0 to point ---
+        result = fabs(value) * (pointY/pointX);
+    } else {
+        //--- scale on line from point to 1 ---
+        float m = (1-pointY) / (1-pointX);
+        result = fabs(value) * m + (1 - m);
+    }
+
+    //--- return result with same sign as input ---
+    if (value >= 0) {
+        return result;
+    } else {
+        return -result;
+    }
+}
+//function that updates a joystickData object with linear scaling applied to coordinates
+//e.g. use to use more joystick resolution for lower speeds
+void joystick_scaleCoordinatesLinear(joystickData_t * data, float pointX, float pointY){
+    //scale x and y coordinate
+    data->x = scaleLinPoint(data->x, pointX, pointY);
+    data->y = scaleLinPoint(data->y, pointX, pointY);
+    //re-calculate radius
+    data->radius = sqrt(pow(data->x,2) + pow(data->y,2));
+    if (data->radius > 1-0.07) {//FIXME hardcoded radius tolerance
+        data->radius = 1;
+    }
+}
+
+
 
 
 //=============================================

main/joystick.hpp

@@ -132,10 +132,24 @@ float scaleCoordinate(float input, float min, float max, float center, float tol
 //====== joystick_scaleCoordinatesExp =======
 //===========================================
 //function that updates a joystickData object with exponentionally scaling applied to coordinates
+//e.g. use to use more joystick resolution for lower speeds
 void joystick_scaleCoordinatesExp(joystickData_t * data, float exponent);
 
 
 
+//==============================================
+//====== joystick_scaleCoordinatesLinear =======
+//==============================================
+//function that updates a joystickData object with linear scaling applied to coordinates
+//scales coordinates with two different slopes before and after a specified point
+//slope1: for value from 0 to pointX -> scale linear from  0 to pointY
+//slope2: for value from pointX to 1 -> scale linear from pointY to 1
+//=> best to draw the lines and point in a graph
+//e.g. use to use more joystick resolution for lower speeds
+void joystick_scaleCoordinatesLinear(joystickData_t * data, float pointX, float pointY);
+
+
+
 //=============================================
 //========= joystick_evaluatePosition =========
 //=============================================