May 15, 2018 at 8:41 am #49946
I am a hardware designer but occasionally hack up some code – mostly minor mods to existing code… I have the OSPi and having a hard time understanding the options for software and what would be best (easiest) to extend with some features I want. There is the unified software and SIP python and possibly others. I am wanting to add some pressure monitoring of a creek pump (with a 0-5V signal) but am more comfortable doing this on an arduino so could do it independently. USB to the Pi and some scripts on the Pi to notify me of conditions via email/text. Also interested in an LCD and keypad for local control but a cheap tablet might be better, a lot less work and cost not much more. Or I could just use the app with my phone. I see that SIP has many plug ins for sensors, LCD, keypad, etc. I fear that whatever path I take I may spend lots of time fiddling with things to make it work. On top of that there have been updates over time so many of the older posts and pages may have information that is no longer valid.May 15, 2018 at 11:21 am #49948
What do you want to do with the pressure data you get from the creek pump? You might be able to have the Arduino make API calls to the unified firmware.May 15, 2018 at 11:46 am #49951
The pressure sensor will have two uses. Check that the pump is actually pumping and hasn’t lost prime. And check that the output pressure is not too much lower than normal (set points to be determined). Basic function that I am thinking of (set points subject to change) is:
Within 2 minutes of startup have pressure of at least 30 PSI. If not shutdown pump and send email notification.
If the pressure drops below 35 PSI send a warning email that the pressure is low so I know to clean the filter.
Unless I incorporate this into OS I will run the pump signal from OS to an input on Arduino. Then an output pin on Arduino will control the relay for the pump allowing shutoff of the pump independent of OS. Probably just an Arduino Uno that sends status messages to the PI over USB serial. Then a script on the Pi that can send emails (and possibly make API calls to OS). Not putting the Arduino directly on the network. I’ve done similar things like this before – it could probably be done in a more technically elegant way but this way is fairly simple and easy and gets the job done.
If I could do this in OS that would be great but I don’t want a major project.May 15, 2018 at 12:07 pm #49952
That makes sense. My suggestion would be to not use an Arduino at all. You’ve already got a Pi in the system. From your description it sounds like the Pi can do all of the functions that the Arduino would do – in addition to controlling the OS. If you eliminate the Arduino, you’ll have a simpler hardware (and likely software as well) setup. I’d eliminate the Arduino and then write the code to monitor the pressure and take the desired actions all from the Pi itself. I’m thinking the code would be independent of the OS code. If your pressure isn’t where you want it to be, you use the API to turn off the running programs and maybe you also need the relay to shut off the pump. The relay can be controlled by the Pi.
MikeMay 15, 2018 at 12:52 pm #49955
Making independent software on the Pi makes a lot of sense. Thanks for the suggestion – I hadn’t considered that.
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