Using an arduino Uno to hook up to peizoelectric sensors.

I am using an arduino Uno to hook up to peizoelectric sensors and read voltage of false eggs in a reconstruction of a sea turtle nest. I am testing four sensors. They seem the same, except two have weights and two do not. I think AnalogReadVoltage will work, although I am unsure. I will include the datasheets. I am unsure of where to plug in the pins, and if the connectors are solderable. Please send some help. Any additional information I will include apon Request. Thanks.

Data sheet for SEN-09199 vibration sensor.pdf (454 KB)

SEN-09197 vibration sensor datasheet.pdf (817 KB)

ALSO THE SENSOR FROM THIS LINK!

As far as I can see you need to treat the piezo sensors differently from the resistive sensor.

I would try attaching the negative piezo sensor pin to ground and the positive to an analog input and write a short sketch to print the numbers detected. Be careful in case the sensor produces more than 5v which might damage the Arduino. If it does, you could use a couple of resistors as a voltage divider to bring the voltage within range for the Arduino.

With the resitive sensor you will need another resistor to make a voltage divider like this

Arduino 5v ---- RESISTOR ----- SENSOR ---- Arduino ground

You would then use the analog input to measure the voltage between the resistor and the sensor. Life may not be so simple, however, because the sensor seems to have a very high resistance and I'm not sure how that will work with the analog to digital converter. At best I think you may have to leave a considerable time between readings. I suggest reading the Atmega 328 datasheet.

...R

The pins should be solderable.

Regarding the piezo sensors - you need to solder them (quite firmly) to some sort of PCB such as a "protoboard" with solderable "lands". On the other hand you would have to devise some means to apply pressure to the resistive sensor body itself on movement.

The piezos generate AC and have an effective series capacitance. You could connect them to a digital input through a resistor of say, 10k and allow the protective diodes of the ATmega chip to constrain the input voltage between 0 and 5V, so that if the sensor is sufficiently excited, it will generate transitions. Note that this will result in some leakage current inside the chip which limits your ability to use current conservation by "sleep" and such, but that is a limitation to using any sort of analog input.

You can actually use much the same arrangement to make analog readings. The process of analog measurement tends to drain voltage from the input for each measurement, so most of the readings will be (much) nearer ground than 5V.

Paul__B:
The process of analog measurement tends to drain voltage from the input for each measurement, so most of the readings will be (much) nearer ground than 5V.

I had overlooked this. You may need to put an op-amp between the sensors and the Arduino.

...R