Hello Arduino Forum!
I work at a gas station, and the boss makes me messure the gasolin and Diesel levels located in big tanks underneith the station.
This is OK at summertime, but this is a hassle at wintertime (I live in Norway...)
However.
After some Googling, I found that there exsists sensors for this exact purpose.
These will give me a report in form of 2 to 200 milli Amperes. It manipulates the voltage to make this possible.
I understand that this i the most used industry standard for this kind of sensors.
After a night of playing around with my Arduino Uno and a develpoerboard, I had made a "sensor-wanna-be" that feeds the Arduino with emulated sensor voltage. The Arduino is reading the "sensors" and displaying the levels on two 7seg. displays. It also buffers up the data, and lets a computer download the log using serial comunication.
But here comes the problem:
If this is ever going to make my work easier, then I will have to make sure that it is up to industry standards too.
That means that the inputs must be protected (with optocouplers?), the output will have to be protected with resistors, and the power will have to accept 9 to 36 volt...
Googling optocouplings, it tells me that the input side typically starts opening at 200mA. This will not work for me.
How do I get the optocouplers to "transmit" 2-200mA sensor data?
If I get this to work, my work will be a lot nicer for me and all the other employees.
And I bet my boss will love me for it ;-)