Silly ASD1115 question and some sensor chit chat

So I finished my mushroom fruiting chamber thanks to Kyle’s video. I had this task in my head for over 3 years and I am surprised it all works :slight_smile: So I got a bit braver and am eyeballng a hydroponic tent. And I have a couple of questions.

  1. Would it make more sense to have a separate R Pi for the hydro tent or would I be fine just adding more sensors to the one currently running mushroom chamber and just creating new dashboard for the hydro stuff?
  2. I would love to be able to use all the sensors from Kyle’s video to make sure I don’t have to troubleshoot something I am not well versed in, but Atlas Scientific sensors are very hard to get in EU and they cost an arm and a leg. To get the ph+temp etc from Atlas would easily cost me ±300-400 Euros which would squash the idea of this project. I see mycodo has the Texas Instruments DS1115 as option in the inputs. Do I understand it correctly, that I can buy an analog PH meter (smth like this) and then would need to wire the chip that reads the PH from the probe to the DS1115 and then that to RaspPi?
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A single Pi 4 should be able to run both the mushroom chamber and a simple Hydroponics tent simultaneously.
For a simple and effective hydroponics system you really only need:
one temp / humidity sensor (SHTC3 or SHT3x or SHT4x will all work fine),
water pump (small submersible fountain pump 100 to 300 GPH will work fine),
and fans (preferably fans that can be speed controlled using PWM signal… 4-wire computer fans and AC-Infinity or Vivosun brand tent fans can all be speed controlled)
A humidifier would also be good to install in the tent for VPD control, but it is not absolutely necessary.

For the hydroponics you really only need a single temp-humidity sensor, and you don’t need expensive ones since the humidity in the hydroponics tent should really never go above 70%. You do not need a pH sensor either since the cheap ones don’t last very long. Even if you buy the very expensive pH sensors, they still need regular re-calibrating and probably won’t last more than a year with constant use… it takes less time to manually test and adjust your pH using testing strips or drops than it does to calibrate an expensive pH sensor. It’s easy to test the pH by hand once every 2 days since you will have to top off your nutrient reservoir with fresh water at least that often anyway. You also don’t need the auto-dosing system to mix the nutrients. You will be cleaning out your system to remove algae and sediment and mixing a new tank of nutrients about every 3-4 weeks, so it’s just easier to do it by hand instead of building and calibrating an expensive and complicated dosing system. In fact, it would be much more practical to setup a water level sensor and an electric valve to automate the topping-off of the reservoir than building a nutrient dosing system. You also do not need an EC/TDS sensor (total dissolved solids)… if you always follow the nutrient manufacturer’s recommended mix ratios for the nutrients you plan on using, and you keep the reservoir topped off with fresh water every day, you should never have problems with the EC/TDS going too high.

Just seconding @Lucid3y3’s comment, EC and pH sensors aren’t necessary, but can be beneficial if you have a large system, you want to get familiar with automating liquid dosing, or you just really want to automate that part of a smaller system. For small systems, manual adjustments aren’t that difficult or time consuming. Only when you scale your system and reservoir does it become more critical to get water chemistries right, since there’s more at stake.

One Pi can monitor/control several systems. Just understand that if your Pi stops working, you may have all your systems stop working. It really depends how much risk you’re willing to take. You can mitigate the risk by using an SSD instead of an SD card, adding a UPS to prevent potential data corruption to the Pi when there’s a power loss, adding a real time clock, putting everything in a case/panel to protect from water/humidity/physical damage, etc.

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Thank you both! I think part of why I wanted to replicate Kyle’s setup from the video is to prove to myself that I can and I really like advanced (and perhaps overengineered) systems as a thing. And as a proof to myself that I can actually do it. My first build is using your mushroom guide where I have a humidity/co2/temp sensors along with wifi sockets that control humidifier and fans that kick in when needed. And the PI is with the PI CM4 module that has 32GB storage built in. All packed in a nice isolated box as you showed in your instructions. Again, can’t say enough on how grateful I am to find a video with a very detailed instruction and also (probably even as important) the exact part list.

For hydroponics I don’t want anything bigger than what you showed in your video as well. I want to test it out and see if I can actually grow enough simple stuff like salad/spinach and have it as automated as I can. If this works I might scale this up to add more things to grow for myself and my wife.

I was a little dissapointed after lucid’s comment where you say the sensors won’t last anyway and will be in need of constant calibration. My dream of having something stable and automated shattered :slight_smile: I might then start with the setup according to Kyle’s video and skip the dosing /ph part, but then the whole thing stops being a smart setup. I can measure the temp of water or humidity but I don’t see how this might benefit, so in the end I don’t really see the point of having a PI connected to the hydro setup anyway. Or am I missing something?

If you are planning on growing simple leaf crops like lettuce, basil, spinach, etc. I would actually recommend a DWC or even a raft type system over the trough system in the video. It would be much simpler and less expensive to build, and also simpler to maintain. DWC systems are about as simple and “stable” as you can get with a hydroponics system, and they are also easy to scale up, just add another tub. And all you would really need to run it is a couple of programmable wall-timers. But having the Pi and Mycodo controlling it will allow you to monitor temps and humidity and take time lapse photos to help track progress. It doesn’t really take a lot of automation to grow most plants, they are far less finicky than mushrooms :slight_smile: If you have a DWC type system, automating the pH control with a dosing system and a sensor, as well as implementing a water-level sensor and an auto-refill valve for topping off the reservoir every day with fresh water, would be all the automation you need to run it almost hands-free for about a month before you would need to clean it and mix a new fresh tank of nutrients. The caveat is that you will need to spend the $$$ for a good quality reliable sensor that will last, and you will need to care for that sensor in order to make it last and keep accurate readings… that’s the trade-off… Don’t use a sensor and you have to manually check and adjust pH at least every 2 days. Use a sensor, and you have to keep the sensor clean and calibrated once in a while to make sure it is working properly, as well as keeping the dosing pumps calibrated once in a while… there is always some maintenance, no matter how much or little automation is designed into any system. As the Klingons say, “Choose your pain.” :rofl: