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  • Author Author: nandohila
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Upcycle It - Washing Machine Hydroponic Grower - #5 Circuit Design

nandohila

Most of the heavy work was complete, it is still missing the water tank and pump connection thought.

 

Now is time to describe how the system will work and establish bases to start sketching the program.

 

We will start with a very basic design to have the rotary growing system going and as we go we can implement more sophisticated functions or add more sensors and controls.

 

Below is the block diagram showing Inputs and Outputs connected to the Intel Edison Arduino Board and a brief description of each I/O.

image

 

OUTPUTS

 

     Stepper Motor turns the drum continuously at an RPM set through the remote dashboard;

     Grow Light switches On/Off at times set through the remote dashboard;

     Water Pump switches On/Off at a frequency set through the remote dashboard;

     Fan switches On/Off depending on the temperature and humidity readings.

 

INPUTS

 

Sensors:

Light Sensor records the grow light intensity and sets an alarm if the Grow Light is set on but there is no reading;

Temperature Sensor records the temperature inside the drum and switches the Fan on if temperature is above set limit;

Humidity Sensor records the humidity inside the drum and switches the Fan on if humidity is above set limit;

Water Level Sensor sets an alarm if the water level is lower than the set limit;

PH Sensor sets an alarm if PH reading is out of the set limits.

 

Switches:

Auto/Manual Switch gives manual access to the next switches bypassing the programmed instructions;

Motor Switch turns drum motor On/Off

Light Switch turns grow light On/Off

Water Pump Switch turns water pump On/Off

 

Using Fritzing we created the sketch below showing the actual connections to the Intel Edison Board.

 

image

 

Having the basis to start programming and connecting the components to the board we will use the Arduino IDE to program the board. The programming instructions will be presented on the next posts.

  • in reply to rsc

    Even the opto-coupled relay boards that you can purchase need to be treated carefully.

     

    While they provide isolation some tie the input side to the same voltage they use to drive the relay ... so not really optically isolated.

     

     

    Many of the relay units have a LED in series with the Opto-coupler and a resistor.

    The voltage drop is not enough when driven from 3v3, and the trick is to reduce the resistor value down.

     

    To safely drive the relays, you should use the level convertors on the Arduino Breakout board, or use a transistor to do the actual driving.

     

    Mark

  • I agree with Scott.

     

    Usually you do not want to exceed more than about 20mA on the outputs.

    Use a driver transistor or a MOS FET and you can do the job.

     

    DAB

  • Hi Fernando,

    The Edison Arduino board may not be able to drive your relays directly (32mA @ 5V).

    I've had problem with some Arduino shields on the Edison board because of this.

    Scott