Upgrade Your Bluetoth Headset Battery CapacityView Instructable »
I am planning to get an oscilloscope. I will try to calibrate with it too, for sure!
Yes, that correct. Twice the frequency is used to calculate the vibrations per hour. I used the frequency because it was easy to do the math.
Calibrate a Mechanical Watch Using Sound WavesView Instructable »
DIY Wattmeter using Arduino UnoView Instructable »