Kinematics: Output is different than Calculations

Hello! I don't know if this is the right forum to ask this question, but I am currently working on inverse kinematics for a quadruped. I am using servo motors and I am using the law of cosines in order to find the initial angles for the legs. I have attached my code and output below. My problem is that when I enter the height (angleVal[2]) the output is spitting out wildly different numbers than expected.

The height is set to 189, the thigh and legs are set to 133.9. When I enter this into a calculator it gives me the correct initial angles which are 45 degrees for the shoulder and 90 degrees for the knee. I don't know why my output looks like this please help!

 int angleVal[]={0,0,189.3};

  if(radio.available()) {

      Serial.print("X1:  ");
      Serial.print(" || Y1:  ");
      Serial.print(" || counter:  ");
      //kinematics(angleVal[0], angleVal[1], angleVal[2]);

  float shoulder1 = sq(thigh) + sq(angleVal[2]) - sq(leg);
  float shoulder2 = 2 * thigh * angleVal[2];
  float shoulder3 = shoulder1/shoulder2;
  float shoulderRad = acos(shoulder3);
  float kneeRad = PI - (shoulderRad * 2);

  float shoulder = shoulderRad * (180/PI);
  float knee = kneeRad * (180/PI);


  Serial.print(" || shoulderAngle:  ");
  Serial.print(" || knee:  ");


An int can never be initialized to 189.3. 'int' means "integer".

1 Like

Thank you so much, I didn't even realize this! perfect fix.

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