advice needed for aquaponics sensors
mrsaucier
Posts: 3
Howdy Parallax community members and electronics enthusiasts.
I need some serious advice concerning the choice of sensors I need for an aquaponics automation project...
WTF is Aquaponics?
Aquaponics is a method for growing plants in a hydroponic setup and using fish waste and various beneficial bacterias for fertilization. Basically the aquarium water is circulated in the hydroponics growing beds and gets filtered by the plants.
The project.
I am planning to gradually automate the whole setup by monitoring various environment caracteristics and taking various actions accordingly. I plan to build an embedded solution based on the maple board from leaflabs. Here are the details of each aspects of my project.
Phase 1 : Lighting
The lighting solution will consist of a light sensor capable of measuring ambient light from 0 lux to direct sunlight. Exact measurment is not required, the unit will be calibrated using the direct sun as maximum reference. The microcontroller will then read the ambient light value and drive high power leds to maintain optimal light level for the plants without wasting energy. I would also like my light fixture to be able to move up and down over the plants using motors driven by the microcontroller to keep it at a constant distance from the plants, using a distance sensor (ultrasound?)
Phase 2 : sensing the environment
I need (wish) to monitor those various conditions :
- air temperature
- air humidity
- air CO2
- water temperature
- water ph
- water dissolved oxygen
- water nitrate level
- water on the floor (detecting leaks)
Your comments will be much appreciated.
I need some serious advice concerning the choice of sensors I need for an aquaponics automation project...
WTF is Aquaponics?
Aquaponics is a method for growing plants in a hydroponic setup and using fish waste and various beneficial bacterias for fertilization. Basically the aquarium water is circulated in the hydroponics growing beds and gets filtered by the plants.
The project.
I am planning to gradually automate the whole setup by monitoring various environment caracteristics and taking various actions accordingly. I plan to build an embedded solution based on the maple board from leaflabs. Here are the details of each aspects of my project.
Phase 1 : Lighting
The lighting solution will consist of a light sensor capable of measuring ambient light from 0 lux to direct sunlight. Exact measurment is not required, the unit will be calibrated using the direct sun as maximum reference. The microcontroller will then read the ambient light value and drive high power leds to maintain optimal light level for the plants without wasting energy. I would also like my light fixture to be able to move up and down over the plants using motors driven by the microcontroller to keep it at a constant distance from the plants, using a distance sensor (ultrasound?)
Phase 2 : sensing the environment
I need (wish) to monitor those various conditions :
- air temperature
- air humidity
- air CO2
- water temperature
- water ph
- water dissolved oxygen
- water nitrate level
- water on the floor (detecting leaks)
Your comments will be much appreciated.
Comments
Welcome to the forums,
Parallax sells a lot of different sensors and you might find that the Propeller chip works well with practically all of them. The Propeller chip handles sensors, information display, data recording, and servo motors, etc. very well - and often at the same time thanks to its parallel processing capabilities.
My advice would be to poke around their selection of sensors and see what strikes your fancy. But, just as an example, check out these:
For light sensing, you might consider this:
http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/tsl230/List/0/SortField/4/ProductID/88/Default.aspx
For CO2, maybe consider this:
http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/co2/List/0/SortField/4/ProductID/598/Default.aspx
For temperature, I like to use the DS18B20. http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=DS18B20%2B-ND
More specifically, I was wondering if the ultrasoud PING))) sensor would be suitable to detect distance from a plant, and which light detector would suits best the application (rough estimate of light level from 0 to full sunlight), would a photo resistor be suitable for that application?
Thank you for your time.
I don't have any experience with the PING but I'm guessing it might suffer from having its sound waves pass through the plants and not really give a good reading on distance. Perhaps a system that detects the shadow of the plants projected on a wall or something might be a better way to go but it wouldn't give you three-dimensional information, just a profile of the plants.
The TSL230 chip that I pointed out can give light readings that range from about, say, the light level of a basement with a single window during a cloudy daytime... up to an above-ground room with many windows on a sunny day, though not in direct sunlight. It interfaces very easily with a Propeller because the output of the TSL230 is a simple frequency that I think relates in linear fashion to the light it detects. If you were to use a photoresistor, then you would need peripheral circuitry to convert the resistance values into something your Propeller or Stamp chip can read. Such peripheral circuits aren't difficult to do, but I think the TSL230 makes things a lot easier.
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=QRE1113-ND
These emit infrared light from one point and detect it at another so if an object gets within a certain distance, the sensor will emit a signal back to your processor.
You can make your own from IR emitters and detectors, too. So, if you've got some way to move such a sensor toward your plants, you can measure the distance to a leaf that way.
It's just a thought.
For detecting leaks (water on the floor) you can build your own simple conductive or capacitive sensors.
To maintain the light fixture a fixed distance above the plant tops I would suggest one of three approaches. The first would be to measure the reflected light from the plants using a photosensor. Since you are also measuring the amount of light on the plants you could use the ratio between the incoming and reflected light to control the light fixture height.
The alternative would be to have several IR leds along one side/end of the plants and photosensors on the other side.
The third (and probably over the top as far as compexity) would be to use a camera and analyze the image to determine the average plant height.
Duane
I know this project will end up being expensive. I will take it one chew at a time. I will post my progress here, be patient.
http://atlas-scientific.com/
They make little boards that take an imput from a normal ph, orp,etc. Sensor, and convert it to a serial signal that just about any micro can read. I haven't used them yet, but plan to for an automated pool system.
Also, they have the probes that might also be good for your aplication.