building a v2 based smart aquaponics garden

aquaponics uses bacteria to break down fish waste to grow plants without soil in a recirculating water system. smart aquaquaponics allows you to use your computer or mobile devices to visualize and control your aquaponics garden remotely. a typical garden is shown below:

in this post we will looking at required material lists, how to build the physical garden and how to connect sensors to the garden. the following are diy instructions on how to go about building a kijani grows v2 based smart aquaponics garden like the one that will give you plates and years of fresh yummy micro-salads on demand.

materials list:

• aquaponic garden instructions/materials
• v2 smart controller board
• 8 basic sensors
  • temperature, 1-wire
  • infra-red growbed level sensor, analogue
  • light level, analogue
  • leak sensor, digital
  • flow rate sensor, digital
  • flow switch, digital
  • tank level float switch, digital
  • reservoir float switch
• 9v psu
• an ethernet cable
• 1 ecological safe enclosure
• 8 5mm panel mounted audio sockets
• 8 5mm male to male headers
• pcb header wires.
• 4 way smart control power strip

building the aquaponics garden

detailed instructions on how to build such an aquaponics garden can be found here  of course the same instructions will work for many an aquaponics or hydroponics garden.

adding sensors to the garden

aquaponics is fun on its own because it integrates multiple life forms. the v2 smart controller allows us to have even more fun with our gardens from anywhere in the world. It does that by transform the physical garden environment into digital data for visualizing, analysis, automation, remote control, monitoring, alerting. the v2 controller makes the garden searchable and shareable. using sensors and actuators, the v2 controller allows us  to interact with the physical garden environment.

we will now look at how the sensors connect to the physical garden. later on we will connect these to the v2 smart controller for data collection and remote control

• the 8 basic sensors we will  use are shown below

• flow rate sensor: the suns energy through the pump makes it possible to create a water cycle in the garden system., it is the input energy that sustains the system heartbeat in the gardens ebb(flood) and flow(drain) cycles. catastrophic failure or degradation issues from bio-slime building can not be allowed on the pump or irrigation lines. the flow rate sensor allows for monitoring of pump performance. the flow rate sensors goes inline in the pipes or tubes connecting the pump with the irrigation. this type of sensor specifically connects to an interrupt pin. to read hall effect sensors, we keep everything quite for a second and count the pulses received on the interrupt line then use this to figure the flowrate in gpm.
• temperature sensor:,a 1-wire water proof probe for monitoring  the goes inside the fish tank temperature goes inside the fish tank, or outside for ambient temperature. I think 2 or more is better. since 1-wire devices are addressable, all the temperature sensors are connected in parallel to the same pin with the same connections. The v2 controller software will distinguish between multiple 1-wire sensors. this sensor specifically connects to pins configured for 1-wire operation
• growbed level sensor: the growbed is like the lungs for an ebb(flood) and flow(drain) garden. water raising in the growbed pushes out stale air out whereas water draining in the growbed sucks in fresh air oxygenating fish, plants and bacteria. using infra-red distance sensors embedded in a pvc pipe we can measure the water depth inside the grrowbed. The sensor pvc pipe can reset inside the drainage gravel guard or buried directly inside the gravel. this is an analogue sensor
• photocell ldr sensor: plants need light to make food through photosynthesis. monitoring this is especially important if you are using indoor grow lights for your garden. i think it is also fun monitoring ambient light levels for gardens without grow lights. i put is on the pole holding the grow lights upright. this is an analogue sensor

• flow switch sensor: this is used to monitor the grow bed drainage back into the fish tank. The flow switch goes in-line on the grow bed drainage plumbing underneath the growbed. I monitor the drainage because my choice of basic sensors is based on what I consider an input or output to the garden. this is a digital sensor

• tank level sensor: we don’t want our fish to die so make sure they have enough water. this sensor is a float switch can detect the level of water in the fish tank. If this drops below a certain point we can refill the tank automatically using the v2 controller. I put the float switch in the fish tank using a wire of suction cup about 6″  from the top of the fish tank.. This is the minimum amount of water i need left in the fish tank when the grow bed is full of water. You can experiment with your tank/pump settings. this is a digital sensor

• reservoir  level sensor: the one task i have never liked is refilling water. using a water reservoir system allows me to treat the fish water and refill the fish tank on demand. This is  a float switch goes in the bottom of reservoir container so i can know when to add more fish tank backup water. This process can also be used say control a reverse osmosis water system for refilling. the amount of water being used from the reservoir system is one of the ways i can tell how much water is being used by the garden. this is a digital sensor

• leak sensor: leaks are no fun so the sensor sits on the floor somewhere suitable next to the garden. leak detection allows the system to be shut down if leaks are detected before fish die or property is damaged. this is an analogue sensor.

 v2 smart controller

the v2 smart controller is a linux/arduino based board designed for interacting and controlling physical environments from anywhere in the world. originally designed for smart aquaponics it can be used for any supervisory control application. the v2 board comes with enough onboard hardware to replace more than 10 shields. It also comes with all the software required to get real life monitoring and control applications up and running in no time. All that is required is to connect your sensors, relays, assign a unique name and wifi password to visualize and control your application remotely. A typical v2 smart controller board is shown below:

connecting garden sensors to the v2 smart controller

V2 smart controllers support different sensors including digital sensors(eg a float switch), analogue sensors(eg photocell),  1-wire sensor(temperature), i2c, serial and usb based sensors The v2 board can interface most of  these directly without any extra external circuitry.

the 8 basic sensors that we connected to the garden are listed below with the corresponding  pin number and data type shown

• temperature, 1-wire, D26
• infra-red growbed level sensor, analogue, A4
• light level, analogue, A1
• leak sensor, digital, A2
• flow rate sensor, digital, D2
• flow switch, digital, D8
• tank level float switch, digital, D6
• reservoir float switch, D23

connecting digital sensors

connecting digital sensors to v2 controllers using internal software based pull-up resistors is easy because digital sensors mostly  have two  connections, or three if they are active and require a power source. One contact connects to the respective digital pin eg D4 on the board and the other contact is grounded. the arduino style syntax for activating the internal pullup resistor is:

: pinMode(4,INPUT_PULLUP); where 4 indicates that the internal pullup resistor on digital pin D4 is activated

a schematic for this is shown below:

connecting analogue sensors

connecting analogue sensors to a v2 controller is easy as well as they mostly have two pins or three if they are active sensors types. One of the analogue sensor is connected to the analogue pin such as A6 and the other to ground. internal pullup resistors can be activated on the atmega chip as well. but they are not accurate for critical analogue sensor measurements. so  ten analogue input pins A10-A9 have an onboard  switchable pullup 10k resistor through the dip switch on the v2 board. These are activated through the respective on-board dip switch. a schematic for this is show below:

connecting 1-wire digital sensors

Connecting 1-wire digital sensors to a v2 controllers is also very easy as well. 6 pins D26, 27, 28, 29, 30, 31 have a switchable 4.7k parasitic resistor connected. These are connected to the respective dip switch. pin D26 is preconfigured for 1-wire dallas temperature sensors, whereas D27 for the typical arduino humidity/temp sensor. A typical schematic is shown below;

wiring sensors

typical 8 basic sensors are shown below. depending on application needs, some of these may vary slightly

in the following examples, we will use pcp header wire and heat shrink sleeves to wire sensors for connection to the v2 boards pcb headers. wiring a typical float switch sensor for connecting to the v2 board is shown below. this process is similar for most digital sensors. though some may require a vcc voltage

wiring 1-wire temperature sensor is shown below. multiple 1-wire sensors can be wired the same way in parallel. this process is similar for more 1-wire sensors

a ldr photocell sensor is wired below. this process would be the same for most analogue sensors.

a leak sensor is wired below. these can be connected in parallel for more coverage.