In this lecture, I'll talk about the hard work requirements for this project in choosing hardware components,
I prioritize the flexibility and simplicity.
It should be possible to substitute any of the components with equivalence and still be able to complete
the project without modifications in the software.
I also chose components that are easy to find no matter where you are in the world.
Almost everything I show you in this lecture is generic, meaning that you can get parts from different
ventus at very low costs.
The only exception is the Raspberry Pi, for which there is no 100 per cent compatible alternative to
the genuine board.
But even there, the alternatives.
Of course, you'll need a Raspberry Pi, any model will do as long as it includes ADENHART or Wi-Fi
networking, and you can install the Raspberry Pi OS on it from a ten dollar Raspberry Pi zero w to
the latest Raspberry Pi for the work.
I have used an old Raspberry Pi to.
Having said that, you actually do not need a Raspberry Pi at all.
At the very least, you need a computer on which you can store and run the node rate and make it mosquito
services.
It could be a laptop or a virtual machine with the Knicks running on your computer or a banana pie,
perhaps AAUP to square red and or droid x2 for or an imagination creator.
S.I 20.
As I said, the only real requirement is that whatever you choose, it can run the node red and disservices.
If you choose to use anything other than the Raspberry Pi, you'll have to figure out how to install
those services yourself.
But if you are comfortable with that, go for it.
The microcontroller I've chosen for this project is that E.S.P 32 implemented on a generic development
kit version one point one, I chose the E.S.P 32 as opposed to a regular Arduino like the UNO because
of the integrated Wi-Fi.
The one that I use is marked E.S.P 32 s the onepoint wonderful version, one point one and has 38 pins
with a pitch between the two rows of twenty two point ninety five millimeters.
And I chose it because it fits nicely on my breadboard.
There's no other specific reason I've tested the exact same sketch on a few other, especially two deaf
kids that I have, such as a 40 pin and 30 pin variant, including one with an integrated LEPO battery
and charging circuit.
And that worked perfectly.
I also tested a modified version of the sketch with an Arduino Nano 33 Iot, and it worked equally well.
As with the Raspberry Pi, the choice of Mac Montrealer is flexible.
The only requirement is that the controller you choose has Wi-Fi or Ethernet communication capability,
and it has an M Quiddity library so that it can work.
Sanctity client.
As with the Raspberry Pi, if you choose to use anything other than the E.S.P 32, you'll have to figure
out how to modify the sketch to work with your choice of MCU.
So I encourage you to go with the ESB 32.
In the photo that you see in this slide, you can see all of the hardware components that are needed
in this project, apart from the Raspberry Pi and the added to this, a motor at DHT 22 sensor, a potential
mirror and a few other things that I'll describe later here.
I want to concentrate on the motor and the potential motor because I don't want to be working on the
project with that terrarium jar or filled with soil and a plan in it and a water reservoir on my workbench.
I've replaced the actual soil humidity sensor with a potential mirror and the actual water pump motor
with a regular Hoby DC motor.
The potential motor is simulating the analog soil humidity sensor so I can develop the software and
test that without having to deal with the actual planned soil and water.
The this motor allows me to test the motor control circuitry and the motor power supply.
Once I'm confident that those individual software and hardware components work, then it can replace
the potential motor and the DC motor with the actual soil humidity sensor and the water pump.
In the photos, in this light, you can see the actual water pump on the left and this soil humidity
sensor on the right side, both very low cost generic components that you can easily find on the Web.
So I suggest that you purchase at least two of each.
I'm using a regular DHT 22 sensor in a special package with extended wires for the power and data pins
like the ones you see in this photo.
The special packaging makes it easy to place the sensor inside the terrarium container.
Apart from this, there's nothing special about this DHT 22.
You can actually use a regular DHT 22.
And so the long, flexible jumper wires to its pins so that you can place it inside your terrarium container
instead of purchasing the modified version in this photo.
To control the pump motor, I've chosen to use a tip 120 122 Darlington transistor, along with a network
of two resistors, one diode and one capacitor.
This configuration allows me to switch the motor on and off with only a small amount of Charente from
the E.S.P 32 instead of a transistor.
You can choose to use a relay which can help with better electrical separation between the motor and
the microcontroller.
In this case, I'll show you how to implement the transistor switch option.
I wanted to implement the ability to measure the input voltage of the ISP 32 and the motor.
This makes it possible to power the terrorism controller from one or two batteries and to generate notifications
when the batteries need to be charged or changed.
The voltage sensing circuits consist of simple voltage dividers.
In this course, I'll show you exactly how to define the resistor values and how to implement the necessary
voltage calculations in the E.S.P 32 to sketch and the code red flow.
If you don't like working with a breadboard, you can implement the hardware on a printed circuit board
at designed a PC B that can accommodate the components you see on the breadboard, along with a 38 PIN
Espiritu deaf kid.
In this course, I'll be working on the breadboard, but in the very end, I'll show you what the implementation
looks like.
Finally, there are a few secondary components I want to mention here.
You need a break, but of course, like the one in the photo, or you can use a couple of many Bridgeport's.
You also need lots of jumper wires and a power indicator so that, you know, when the circuit is powered
on for power, I use the benchtop power supply for the motor and use the power for the E.S.P to hit
the bench.
Power supply was convenient because it also allowed me to test my motor voltage circuit and a different
input voltages.
And finally, a multimeter is always necessary to use in a project like this, I use mine to calibrate
my voltage sensing sub circuits and to take precision readings of their resistor values so that I can
use them in the voltage calculations in the E.S.P theory to sketch.
All this, of course, is explained in the course.