I want to connect an Oil Pressure sender to arduino. I bought the sender on eBay and the specs are 0 to 10 bars (0 to 150 psi) and the resistor range is from 10 to 184 ohms.
I was thinking in reading the value using a voltage divider with a 82 ohm 1% 1/4W resistor.
I've read the following topics, but still have some questions:
On this topic exists the following diagram
Do I really need this ? Couldn't I just use the 5v from the device power source and connect to the oil pressure sensor ?
I have the following information:
At maximum this will get 54 mA. Can I get from the 5v rail in the arduino, or should connect to the DC-DC Step-down powering up the arduino ?
The other problem should be the power dissipation, on the lowest level the resistors will consume 0.27W, and I'm using a 0.25W rated resistor. Should I upgrade to a 0.5W one ?
In the end the wiring scheme should be like this:
Where the first resistor will be the oil pressure sender and the second one the 82 ohms resistor, and I will measure the voltage in A0.