What's going on guys, vald with EEEnthusiast.com here.
In todays video, we're going to be talking about multiplying your analog inputs with
the help of the 74HC4051N IC, which I have in my hand.
This was inspired by a previous video that I've made on a multiplexer which essentially
allowed you to drive different outputs.
Essentially up to 16 outputs with the use of only 4 pins of your Arduino.
Without any further delay, lets take a look at how you can actually read up to 8 different
analog channels on your Arduino by utilizing only one single pin on your A0 channel.
The first step is connecting the hardware, and as you've often heard me say, you will
need to look up the datasheet to fully understand what each of these pins mean and how to actually
connect the IC.
I highly encourage you to take a look in the description of this video and look at the
datasheet for the 74HC4051N IC which I'm using on my breadboard right now.
I'm going to be walking you through the pins, so you don't really have to go in depth.
You will also see a screenshot of the pin configurations right now on your screen.
Lets take a look at some of the connections that we have.
First and foremost, the green cables right here, represent the S0, S1 and S2 on pins
9, 10 and 11 of the IC.
This pretty much allows you to select which analog channel you want to use from the IC
itself and then feed it back to the Arduino.
They are connected currently to pin 8, 9 and 10 on the Arduino itself.
I have the channel which feeds the main, or the selected analog signal back to the Arduino;
which goes into A0 in order to read the analog value.
Next, I have my power and ground busses, so fairly simple.
One thing you want to pay attention to, is that the enable which is pin number 6 on the
IC, needs to be connected to ground.
As you can see, that is labeled by a black cable.
I have pretty much pins 6, 7 and 8 of the IC going to ground.
Next, all of my blue cables, that you see going to the buttons and potentiometer, are
pretty much analog input or analog channel pins.
You will have as I have in my case, 7 buttons and then a potentiometer.
What I'm going to be reading essentially is 7 different signals and a potentiometer.
The last one, as you can see, is jumpered through the button, so if I want, I can use
the button or the potentiometer.
Obviously, the potentiometer just acts as a voltage divider, so I should see a value
of 0 to 1023 on the Arduino serial program.
You will be selecting one of these 8 channels and feeding them back to the Arduino on pin
A0.
Essentially, utilizing one analog channel of the Arduino and three selector pins in
order to read up to 8 different channels.
I'm going to be showing you the actual software, but before that, I wanted to make a quick
mention.
You can also get these breakout boards which would allow you to drive up to 16 channels.
16 Analog channels, same one pin on the Arduino and then you get, obviously, one extra selector
switch.
I'll post the link on my website for this particular board, so you can check that out
if you want to drive even more analog signals.
Lets take a look at the software side.
Alright, so just as a quick reminder, all of this code is going to be available on my
website as well as my github page.
Lets jump straight into the code.
As I've mentioned before, S0, S1 and S2 on the mux are mapped to Arduino pins 8, 9 and
10.
That's what I am doing right here.
The input from the mux is mapped to A0, this is coming back to the analog pin of the Arduino.
The state of the 8 mux channels mapped into this array, so mux1 state 8.
It is initialized to 0.
The setup function; fairly simple.
Three pins set to output.
I had experimented with a digital input as well for the mux, so that's commented out.
Serial dot begin 9600, once again this is used for the console and we're going to be
looking at our array through this feature.
Loop function update.
This is a function which will be defined below; lets take a look before we look at the rest
of the code.
void update mux1, I'm going through the 8 channels.
A very simple for loop, going from 0 to 8; incrementing every single time.
I'm going to write a digital output high based on the bit that is set for the i variable.
Essentially, what this is doing, this is breaking down your decimal, 1, 2, 3, 4, 5, 6, 7, 8
into a binary write.
It writes them accordingly into pins 0, 1 and 2.
Imaging it being a 000 001 010 etc.
All the way up to 8.
At every stage of that setting, I'm reading the analog signal that is being sent to pin
A0.
Essentially, through these lines, I am selecting the channel on the mux and reading the value
of the said channel.
Obviously, storing the said value into my mux1 state array.
Lets come back to the loop function.
Once I've updated the array through one cycle, what I do is, go through the for loop through
all the channels.
0 to 7.
If i = 7, what I want to do is essentially create a jump line, so this is a println Mux
state of i.
Otherwise, I do a simple print on the mux1 state of the current channel and put a comma.
Lets quickly verify the program, upload it to the Arduino and I will show you exactly
what it does.
You can see the useful application.
Serial monitor.
Right now, as you can see, I have all my buttons and my potentiometer initialized.
Lets start with the buttons; if I press the button, it reads a signal of 1023.
Obviously, if the pin is unpressed, it reads a 0, if it is full voltage, or 5v, it's 1023.
Similar to every single other button, all the way to 7.
On the last pin, I have the potentiometer, so this divider will go all the way from 0
to whichever value, all the way up to 1023.
As you can see, I'm reading 8 distinct analog inputs on the Arduino and only utilizing the
A0 pin.
You can already imagine that you can expand this pretty much indefinitely and read all
kinds of analog signals and sensors.
Flow, temperature, if you want to read just a potentiometer reading for whatever reason.
If you have 20 potentiometers, you can implement all of this very easily.
Let me know what you think.
Let me know what kind of applications you would use this for.
Let me know if you want to have some kind of a modification; this IC also allows to
essentially send out a different analog signal to the 8 ports.
In other words, doing an analog out the same way as we're doing an analog in.
As always, thank you guys for watching, make sure to subscribe, make sure to visit my web
page and thank you again for watching.
Bye.