The ram pump with waste capture and feedback ended up being a total bust, although it did actually work. The issue I had in using this was with the amount of additional nutrients that would have been required, given the size of the pressure chamber and the fact that 90% of the fluid goes out the waste valve. While the liquid coming out of the waste valve was recaptured, I had an issue getting the siphoning action to work consistently well.
So.. on to the next (that I know WILL work). Specifically, an airlift (geyser) pumping system. This is actually cool in that it serves two purposes:
- Oxygenates the nutrient mixture
- Is pretty efficient in terms of power consumption
Since its my weekend to have my daughter, we're going to be building and testing the pumping system as well as verifying the operation of the drip system (going with simple here). I'm not very good with CAD, so I'll have to post pictures as things progress.
Additional components ordered that will be here next week:
- Six (6) servo linear actuators for use with the concentrate dispensing system. This system will be capable of accurately dispensing measured amounts of each of the nutrients in the appropriate order into the primary holding tank
- Six (6) small motors that will be attached to small liquid mixers to ensure that the individual nutrient components are mixed thoroughly prior to being utilized with the primary tank.
- Nine (9) electromechanical valves, including three (3) latching valve so that when the nutrients are to be dispensed, the valve can be opened or closed with the brief application of current.
- Relay board
- Current/Voltage monitor module
- 12V air pump
- Peltier device for maintaining nutrient solution at desired temperature
- Thermister for measuring nutrient temperature
Growing related materials purchased/to be purchased:
- 10' 3" PVC pipe and end caps
- Plastic tubing
- One way check valves
- Plastic syringes to be attached to linear actuators for dispensing liquids
- Grow media ("Hydrocorn")
- Mylar sheet
- Screen (if I have time to build the high voltage generator and integrate it into the system)
- Net cups and covers
- General Hydroponics "Flora Series" 3 part nutrient solution
- PH up/down solution
Status of the SCADA system:
Not much has been done with the SCADA system as of this writing. My daughter will be working on the algorithm for various aspects of the SCADA system. Yes, I could do that myself, but I want her to understand what is entailed in designing and implementing an embedded system.
The SCADA system will be responsible for the following tasks:
Nutrient Management
- Accurately dispensing and mixing of the individual nutrient components
- Mixing nutrient tank periodically
- Monitoring temperature of nutrient in tank
- Monitoring nutrient tank level
- Activating/deactivating the nutrient heater/cooler (peltier device)
- Opening the nutrient valve so that nutrients are delivered to the plants
- Activating the air pump for the geyser pump for transferring nutrients back to nutrient tank
- PH monitoring
- Adjusting PH up or down based on PH level
- Activating valve for emptying waste nutrients and flushing system
Environment monitoring and control:
- Checking temperature and humidity from "puck" at determined intervals
- Activating recirculating fan periodically
- ** Stretch goal ** Activate humidity control subsystem (I don't think I've got enough time to build this)
- Activate "grow light" **Stretch goal** Not entirely sure if this is going to happen or not
Power consumption and management:
- Retrieve power consumption values periodically from external monitor
Data transmission:
- Interface with the EZR32WG for IOT connectivity
