May 2, 2019 at 11:08 am #60083
I just received my Opensprinkler Pi board. Paired it with a new RPi 3B+, new Raspian on a 32G SD card. Installed the universal firmware, Hooked it up to my weird and wonderful drip irrigation system, consisting of
* A 19th century “wishing well” ( 5 feet in diameter, 37 feet deep, lined in brick )
* ..with a Shurflo 9325 well pump, powered by
* …a pair of 26A-H lead acid batteries, kept charged by
* …a pair of 100W solar panels driving a Morningstar MPPT controller
The well pump is controlled by a 24VDC relay ( which is what I had in my junk ) , driven by a bridge rectifier from the 24VAC irrigation controller output.
All this drives a “manifold” consisting of about 500 feet of 3/4″ PVC pipe, with three “risers”.
Each riser has a 24V irrigation valve, a hose bib, a large mesh filter, and a pressure regulator.
Our lot is almost an acre, and my wife keeps popping in new fruit trees and ornamental shrubs, and it has officially exceeded the flow capacity of the well pump. So I had to zone it out.
I tried out the system yesterday, and it just worked. Excellent. Now I have to mount it in some sort of weatherproof enclosure. I have a grey, gasketed PVC box that should just about do it. I might have to modify the irrigation transformer a bit to make it fit, though. Or install the SprinkerPi without the laser-cut case. I am planning to install it without any switches, lights or displays, just the grey box with a power cord at one end and the irrigation cable at the other. Control can be done via wifi. I installed a VNC server on the RPi, so I have full access. It works well with “realVNC” on the Windows PC.
As others have noted, the 3B+ is a power hungry little monster, and the built in power supply does not have enough poop to reliably run it. So I gave it it’s own power supply via the micro USB connector.
I need to figure out a way to cleanly power down the Pi. The box is going to have one power cord, and if you unplug it, it all goes away, both the 24VAC irrigation power, and the 5V rPi power. I don’t know what the sequencing will be. It would be nice to have some sort of clean shutdown arrangement; say a supercap or somesuch to retain power for a moment, and a pulse to an I/O bit, such that an interrupt is generated to run a shutdown script.
In the meantime, I just need to get it together and working, so I guess I’ll just plan to use a laptop to shut it down via the VNC.
– JerrykMay 2, 2019 at 9:44 pm #60087
What if you pumped the water to a higher storage tank using solar power during the day and just used the 3B+ to run the solenoids?May 2, 2019 at 11:23 pm #60088
I thought about that. Don’t think the HOA would approve. It would have to be a fairly big tank. The pump maker even told me I couldn’t use their pump to drive the drippers directly, that I should use a tank. However, I chanced it, and it’s been running since 2014. I think the saving grace is that it’s not a very deep well. 37 feet deep, and the water level is generally 11 feet below grade. The total head from the water level in the well to the top of the hill is maybe 70 feet.
Today I packaged the OSPI and the transformer and 5V power supply into a grey PVC weatherproof box. I removed the plastic case of the transformer to save space.
- You must be logged in to reply to this topic.