About 5 months ago we got 3 ducks and trying to keep them busy I have since built them a pond and also a gazebo for us to keep my wife and I entertained. The pond is 2 tiered with a small water falls, homemade filtration system. I have power and hard wired Ethernet conduit-ed to the gazebo with a weatherproof enclosure housing the Pi, relay board, a 5 port Ethernet switch, multi-output power supply and is full of other stuff. From Cayenne I control the circulation pump, turn on/off the lighting and monitor temps so far. Plan on adding PH probe and whatever else comes to mind. Awesome program! BTW - Iāve been using PrivateEyePi for my brewery forever and now canāt wait to implement Cayenne there.
Whatās Connected
So far I have a Pi2 with a 8 relay module and some DS18B20 temperature sensors.
I havenāt done PH as of yet but was looking at the Atlas Scientific EZO ph circuit. As with any PH probes it get expensive. The EZO board is about $38 and the probe another $150. Maybe someone could hack into one of the cheap aliexpress ones.
^cheap probe
They say they can ship to america but I havenāt got a quote yet on shipping.
they have a whole kit for around $100 with board and ph probe.
Iāve ordered a PH probe and board which has an analog output. My plan is to feed that signal into a ADC chip like a mcp3008 thatāll make it digit so the Pi can understand it. Got it off of Ebay from China for under $30. I also thought of maybe a cheaper less accurate approach, A less than $20 PH meter that has an analog gauge on it. I was thinking of looking at the voltage across the meter and feeding that into a ADC. I ordered that too just for fun. Do a search on Ebay for PH monitor.
I got the PH Probe in and the board is one of the ones silkscreened"Logo_PHsensor v1.1".
No documentation comes with it. I have the connections as follows:
Pin 1 V+ = 5v supply
Pin 2 G = Ground
Pin 3 G = Ground
Pin 4 Po = Signal out
Pin 5 D0 = Not connected (Temperature)
Pin 6 To = Not connected (Temperature)
I have the Signal out going to a MCP3008 and the IC is connected to the PI as required for SPI. In Cayenne I added the MCP3008 extension then chose a generic device. In settings I have:
Value
Float
Channel 0
Slider 0 - 4
The icon displays .84 and does fluctuate. So I am seeing the probe and it is be responsive. I wonāt be able to test it with a known PH value until tomorrow to see what ā.84ā actually is as a PH number. Since PH values are usually on a scale from 0 to 14 I will need to figure out how to change the displayed number to the PH value.
I made a daughter board (HAT) that has the MCP3008 (ADC) , ULN2803A (For a 8 channel relay board) and a bunch of terminal blocks. This has connections for 8 relays, 8 analog ins, 4 1-wire DS18B20 temperature probes and power supply connections.
I hope this shows the I attached image. This is inside the duck pond/gazebo controlbox. I 3-D printed din rail mounts for 2 Piā's stacked and for the 8 channel relays. The top Pi is for Cayenne and the one below it is for Kodi. Yes, iām putting in a flat panel up in the rafters for streaming multimedia. Hopefully in the image you can see in the lower right the pub for PH probe.
Well, itāseems been about 7 months since I start the project and all is working well. I did not figure out the scaling for the ph probe but looking at my displayed number (between 3 and 4) and comparing that to actual ph reading (between 6 and 7) I can mentally evaluate where it stands. Currently via Cayenne I control or see 5 temperatures, ph, control pond pump and toggle the gazebo lighting.
I might next spring add a fountain pump and interface more lighting. Depends on other projects that I am working on. Yes, I did clean up the wiring and layout inside the enclosure.
Other things taking up my time are 3D printing on a daily basis, RaspPi stuff and toying with the idea of hacking into my pellet stove controller.
Happy holidays to all.
Jeff (Buzz)
