Measuring Tilt using a Three Axis Solution
In order to define the angles of the accelerometer in three dimensions the pitch, roll and theta are sensed using all three outputs of the accelerometer. Pitch (ρ) is defined as the angle of the X-axis relative to ground. Roll (ϕ) is defined as the angle of the Y-axis relative to the ground. Theta (θ) is the angle of the Z axis relative to gravity.
http://www.freescale.com/files/senso...ote/AN3461.pdf
Here is the meat of the code:
solveangle: '**********Solve for x angle ******************************************** if xresult < yresult + zresult then dummy = 5000 'when x is smaller the following equation works best xlong = (dummy * xresult) /(sqr((yresult*yresult) + (zresult*zresult))) else 'keeps results accurate at near 0 and near 90 degree values dummy =30 'when x is larger the following equation works best xlong = (dummy * xresult*xresult) / ((yresult*yresult)+(zresult*zresult)) endif y = xlong x = dummy 'Assign x and y values for atan2 function call atan2 xangle = 9000 - y if yresult < xresult + zresult then dummy = 5000 'when y is smaller the following eqauation works best ylong = (dummy * yresult) / (sqr((xresult*xresult) + (zresult*zresult))) else dummy =30 'when y is larger the following equation works best ylong = (dummy * yresult*yresult) / ((xresult*xresult)+(zresult*zresult)) endif y = ylong x = dummy ' call atan2 yangle = 9000 - y
Re: How to measure how long I pressed a button ?
in order to measure a buttons hold time you need to either note time button was pressed then the time button was released
richard Today, 04:01the duration is release time - when pressed time, or when button is...