Posts: 16
Joined: Sun Nov 03, 2013 1:02 pm

Rasp Pi to receive signals from Apollo Oil Level Monitor

Sun May 31, 2015 7:59 pm


I have an Apollo ultrasonic oil level monitor on tank. I am planning to design a receiver that can receive the signals transmitted (433 MHz band, FSK), and decode them into an oil level, which it can then put on a web site, use to graph oil consumption, detect oil theft, automatically warn me to order more oil etc.

Has anyone done anything like this? In particular, does anyone know the exact parameters that the Apollo device uses? The exact frequency, the deviation, the digital bit rate, the encoding scheme etc.?

This is very similar to some projects that some of you have done to receive data from a weather station, but of course all the parameters will be different.

If anyone has any information that would help me, please post here.

Thanks - Rowan

Posts: 11
Joined: Sun Dec 30, 2012 5:47 pm

Re: Rasp Pi to receive signals from Apollo Oil Level Monitor

Mon Jun 01, 2015 7:02 pm

I tried doing something similar using the usb display receiver of the level monitor.

Plugging it in it came up as a USB to serial device /dev/ttyUSB0 (or what ever).

Reading the stream in minicom (or what ever you use to read serial streams) It came up with 'readable' junk, of which one item looked like it was the distance from the sensor face to the reflecting surface, I extracted this then converted to a volume using an approximate calibration then uploaded to emoncms for viewing as a graph etc.

Then I made the fatal error of updating the firmware on the receiver, now when I turn on I get a 'readable' output of what I think is the sensor distance to volume calibration, followed by occasional 'unreadable' junk, which I suspect is some (binary?) stuff I don't have the skills to handle.

Then I gave up.

Somewhere on stack exchange is a question I asked about a perl script I made for doing all the above, I'll see if it still exists.

Not thought about using the RF signal from the tank, maybe I'll look in to that if I get time...

Return to “Automation, sensing and robotics”