diff --git a/wled00/wled_math.cpp b/wled00/wled_math.cpp
index 1825ab198..a191968e1 100644
--- a/wled00/wled_math.cpp
+++ b/wled00/wled_math.cpp
@@ -15,17 +15,17 @@
 // Note: cos_t, sin_t and tan_t are very accurate but may be slow
 // the math.h functions use several kB of flash and are to be avoided if possible
 // sin16_t / cos16_t are faster and much more accurate than the fastled variants
-// sin_approx and cos_approx are float wrappers for sin16_t/cos16_t and have an accuracy of +/-0.0015 compared to sinf()
+// sin_approx and cos_approx are float wrappers for sin16_t/cos16_t and have an accuracy better than +/-0.0015 compared to sinf()
 // sin8_t / cos8_t are fastled replacements and use sin16_t / cos16_t. Slightly slower than fastled version but very accurate
 
 float cos_t(float phi)
 {
-  float x = modd(phi, TWO_PI);
+  float x = modd(phi, M_TWOPI);
   if (x < 0) x = -1 * x;
   int8_t sign = 1;
-  if (x > PI)
+  if (x > M_PI)
   {
-      x -= PI;
+      x -= M_PI;
       sign = -1;
   }
   float xx = x * x;
@@ -38,7 +38,7 @@ float cos_t(float phi)
 }
 
 float sin_t(float phi) {
-  float res =  cos_t(HALF_PI - phi);
+  float res =  cos_t(M_PI_2 - phi);
   #ifdef WLED_DEBUG_MATH
   Serial.printf("sin: %f,%f,%f,(%f)\n",x,res,sin(x),res-sin(x));
   #endif
@@ -87,9 +87,7 @@ uint8_t cos8_t(uint8_t theta) {
 
 float sin_approx(float theta)
 {
-  theta = modd(theta, TWO_PI); // modulo: bring to -2pi to 2pi range
-  if(theta < 0) theta += TWO_PI; // 0-2pi range
-  uint16_t scaled_theta = (uint16_t)(theta * (0xFFFF / TWO_PI));
+  uint16_t scaled_theta = (int)(theta * (0xFFFF / M_TWOPI)); // note: do not cast negative float to uint! cast to int first (undefined on C3)
   int32_t result = sin16_t(scaled_theta);
   float sin = float(result) / 0x7FFF;
   return sin;
@@ -118,10 +116,10 @@ float atan2_t(float y, float x) {
   float angle;
   if(x < 0) {
     r = -r;
-    angle = M_PI/2.0f + M_PI/4.f;
+    angle = M_PI_2 + M_PI_4;
   }
   else
-    angle = M_PI/2.0f - M_PI/4.f;
+    angle = M_PI_2 - M_PI_4;
 
   float add = (ATAN2_CONST_A * (r * r) - ATAN2_CONST_B) * r;
 	angle += add;
@@ -140,10 +138,10 @@ float acos_t(float x) {
   ret = ret * xabs;
   ret = ret - 0.2121144f;
   ret = ret * xabs;
-  ret = ret + HALF_PI;
+  ret = ret + M_PI_2;
   ret = ret * sqrt(1.0f-xabs);
   ret = ret - 2 * negate * ret;
-  float res = negate * PI + ret;
+  float res = negate * M_PI + ret;
   #ifdef WLED_DEBUG_MATH
   Serial.printf("acos: %f,%f,%f,(%f)\n",x,res,acos(x),res-acos(x));
   #endif
@@ -151,7 +149,7 @@ float acos_t(float x) {
 }
 
 float asin_t(float x) {
-  float res = HALF_PI - acos_t(x);
+  float res = M_PI_2 - acos_t(x);
   #ifdef WLED_DEBUG_MATH
   Serial.printf("asin: %f,%f,%f,(%f)\n",x,res,asin(x),res-asin(x));
   #endif
@@ -167,7 +165,7 @@ float atan_t(float x) {
   //For A/B/C, see https://stackoverflow.com/a/42542593
   static const double A { 0.0776509570923569 };
   static const double B { -0.287434475393028 };
-  static const double C { ((HALF_PI/2) - A - B) };
+  static const double C { ((M_PI_4) - A - B) };
   // polynominal factors for approximation between 1 and 5
   static const float C0 {  0.089494f };
   static const float C1 {  0.974207f };
@@ -182,7 +180,7 @@ float atan_t(float x) {
   x = std::abs(x);
   float res;
   if (x > 5.0f) { // atan(x) converges to pi/2 - (1/x) for large values
-    res = HALF_PI - (1.0f/x);
+    res = M_PI_2 - (1.0f/x);
   } else if (x > 1.0f) { //1 < x < 5
     float xx = x * x;
     res = (C4*xx*xx)+(C3*xx*x)+(C2*xx)+(C1*x)+C0;