Electronic – arduino – How much current is consumed by an avr analog sensor

Piezo vibration sensors produce a high voltage, but very low current. Further, you are generally interested in sensing only a few things - level of vibration, frequency, amplitude, shocks, etc.

So the interface will depend greatly on what you want to sense. Assuming you only want to know one or more of the following, then the interface suggested below will work.

• A vibration event such as a shock or sudden G force
• The vibration level

The general interface is to push the signal through a diode, then a resistor into a capacitor that's attached to ground. In parallel with the capacitor is a clamping diode that limits the voltage spikes to a more reasonable voltage (5V, for instance).

Now each time a spike happens, the capacitor will charge a little bit. If you have continuous vibration it will charge more quickly. It'll eventually reach the level of the clamping diode as long as the vibration exceeds the capacitor's self discharge rate.

Sense the voltage on the capacitor, and you'll learn about the signal coming in.

If you put a resistor in parallel with the capacitor then you can define how quickly the capacitor discharges. A small resistor will discharge quickly, and you can count how often the piezo is hit or dropped. A large resistor will allow the charge to build up so you won't see individual events, but instead get a higher voltage with more vigorous vibration, a lower voltage with less vibration, and no voltage with no vibration.

If you need more information than this simple technique, then you'll want to use a signal transformer to bring the signal down into the 5V range, and a precision op-amp and ADC.

It says the range can be set to 250/500/2000 DPS, which I think is the maximum angular speed the device can measure (i.e 2000 DPS is the fastest setting)
DPS stands for Degrees Per Second, so 360 DPS means 60 RPM (revolutions per minute) or 1 revolution per second.

The mdps/digit stands for Milli Degrees Per Second, so (I think) for instance the value of 70 mdps/digit for the 2000 full scale range could be converted to degrees per second by dividing by 1 / 0.07 = 14.286. 1 revolution per second should therefore be 360 * 14.286 = 5413 Make sure you are reading the output registers correctly, the data is a 16-bit value in 2's complement (i.e the MSB is the sign bit, then 15 bits for the value)

Try the above and see how it goes.