I have this pair of pressure sensors that are addressable transducers. I want to use them for a project but I don´t really get how to get them to work. I´m used to the type of sensor that has 3 cables( Vcc, GND, and DATA) and these ones only have two cables so I´m kinda lost. These sensors are supposed to give a certain frequency depending on the pressure applied to the sensor.
I found some data on how it's supposed to work but I don´t get what kind of circuit should I use to be able to use this data.
"During the transmission, the sensor modulates the currency at a frequency that corresponds to the measured value at 3.7 mApp (= 0 dBm/600 Ω) onto the DC supply current. Therefore the used pair is power supply (direct current) and transmission media (alternate current) at the same time."
This is how the signal looks when transmitting data.
And this is the actual sensor. Any help on how to use it would be appreciated .
Best Answer
This looks like the device modulates the power supply by drawing current in a data pattern. To measure this you can place a small series impedance (resistor) in series and use a differential opamp to measure it. To remove the DC offset of the normal device current you can add a high pass filter C1 and R6.
Something like this:
simulate this circuit – Schematic created using CircuitLab
Note: You'll need to set your gain, this is just for topology.
Or you can do the same on the ground side, and then just measure it with a single ended opamp.