Electronics for the farm
In this post i am going to cover all of the sensors and parts i will be adding into the farm
(this is currently the plan for the farm but could change over time)
Movement of the farm
The farm will rotate like a ferris wheel (hence the project name)
For the movement i am looking to use a stepper motor to control this and bearings to keep everything aligned
firstly if i use a stepper motor instead of a standard motor i can use the steps to control the positioning of the planters
For example instead of moving the plant at a constant rate i could move it 360/8 degrees every 24/8 hours so each planter will be at a set position this will make it easier to feed and take measurements from the planters while they are stationary and this will also mean that if 1 planter is lacking in water it can move that planter to x position to water it a set amount needed then go back to its previous position
The planters themselves will swing freely (possibly a small amount of friction to stop over swinging or oscillations from the movement of the whole unit
Watering and feeding
For watering and feeding i am going to use a premixed liquid food and water this will be contained in a water tight container either at the back or at the bottom of the design
to pump the mixture to the outlet i will be using a single 5v pump this is a really inexpensive pump at about 2 pounds $3-4
instead of being able to adjust the flow i have decided to go with adjusting the time i will test the motor by creating a chart of how much water it pumps over 1,10 and 60 seconds and also test how long it takes the pump to get the water from the container to the plants this way i can have the pump turned on for the exact amount of time needed
Wind
I didn't initially think about wind as a factor in growing plants it was only when i was part way through my application that it dawned on my that it could play a big role in the health of the plants so i started researching the effects of wind on plants and it turns out that by keeping the plants dry they are less likely to get infected and die
I am going to use a small 2-5cm pc fan at the rear,top,bottom or side of the unit i want to use a small enough fan to create air movement but not to create turbulence
i may also add a second fan as a backup that can be used to lower the air humidity i will cover this more below
Lighting
For the lighting i have two ideas in mind
firstly i would like to use LEDs this would be low energy consumption but i need to research to see if they will give the plants the required lighting they need
the second option is a be light that is designed for plants i have a mount for this already from a animal tank that will fit the bulb this would be high energy compared to the LEDs but i think that this will be the best option
i also am considering using a panel of frosted glass between the light and the plants to give a more even light distribution
Humidity
To control the humidity i will use a second fan for lowering this can be turned on to pump fresh air into the system this fan
for making the environment more humid i currently do not have a plan in mind i have a couple of options
adding a evaporation plat in the bottom of the unit that can evaporate a set amount of water into the air
another option would be to create a miniature misting system for watering the plants instead of dropping the water into the planters add valves to the out flow that will spray a mist into the soil this would then slightly make the air more humid
although i am not worrying much about raising the humidity as i believe that the unit will create its own
Temperature
the temperature will come from the light if i use a tubular bulb this farm will be indoors so any temperature adjustments would be on a small scale and can be done by adjusting the light intensity
Soil moisture
the soil moisture will be be controlled using a soil moisture sensor this sensor
this will let the system know if it needs more water i am going to set this up so that the plants are never over watered if i have the system set up so that the plants to much water it will be hard to lower the moisture but if i have it so that they get to little the system can always adjust to give them more water
the plants will be watered once every 24 hours during the night cycle of the unit and if they are under watered the system can go back to that planter and add more water as required