Arduino Tut. #4 - HD44780 LCD Setup and Programming Video Lecture | Drones for Beginners: How to make Arduino Drones - Electronics and Communication Engineering (ECE)

how's it going guys welcome to the
fourth Arduino tutorial and which we're
going to cover these guys a liquid
crystal display or more commonly known
as an LCD so first we're gonna obviously
discuss the pins as you can see there's
a lot of them so we're going to talk
about what they do what do you actually
need to connect to the Arduino we're
going to see the common hookup and we're
going to see some of the libraries that
are doing already provides for LCDs so
without any further delay let's take a
look at what you're going to need for
this tutorial so for the fourth tutorial
you're going to need a couple of things
you're going to obviously an LCD these
are very common you can get them
anywhere from $5 to $20 on eBay Amazon
now you're going to need a breadboard
you you're going to need a bunch of
jumper wires your Arduino and you're
going to need a couple of resistors one
of them is used for the backlit LCD so
I'm going to show how to connect it soon
and you're going to need either a
potentiometer or a resistor so this is
used for the contrast on the LCD and I'm
going to explain a bit on what it
actually does in a few moments so let's
get right into it so let's take a look
at the data sheet for our LCD so first
and focus you got all the dimensions so
the size of the letters that are going
to appear you have your drill holes and
sizes if you want to mount this inside
of an enclosure so that that's an
important piece of information you have
your headers where they're located we if
we go down we can see the electrical
characteristics so as you can see
typical as five volts you can go between
4.8 to 5.2 supply current for logic 1.5
million so that's what you need to
toggle your pins your backlight is going
to take 15 milliamps so that's typically
just a standard LED
and down here you have your pen
connections and explanation so VSS or
pin number one is going to be your
ground VDD is going to be 5 volts and
your supply voltage be 0 that's the pin
that's regulated through your
potentiometer or a resistance so this is
going to basically adjust the contrast
for your LCD and I'll show you later if
you don't adjust this properly you may
not see anything on your screen arrest
this is a signal for selecting registers
basically it's for read/write operations
and it's going to have a busy flag which
enables you to wait until you send the
next bit so read write read write pin so
if it's high and then you're going to be
in read mode if it's low in write mode
an enable signal so if you set this to
low you're not going to be able to write
or read to your LCD DB 0 2 DB 7 those
are your the 8-bit byte bi-directional
data bus pins there is this LCD allows a
mode which only requires you four pins
so you can only connect four out of the
eight pins to the LCD and I'll show you
can I'll show the connection a bit later
so you don't need to connect all eight
power supply for the backlight and the
backlight ground so this is an LED as
you can see LED plus and minus which by
the way requires a resistance so current
limiting resistance
you cannot just connect a 5 and 0 volts
those pins because you're just going to
burn the backlight all right so let's
look at these pins on the LCD all right
so as you can see there's a little one
in the corner of the LCD and going from
starting from 1 you have your ground we
have the supply voltage we have V 0
which is to adjust the contrast of the
LCD
DRS pin we also have the rewrite pin the
enable pin we have d0 to d7 we are going
to actually use d4 to d7 which are the
four bits as I specified instead of the
eight and then you have the back
light ground and a voltage so let's take
a look at the connections that we need
to make to the Arduino and start writing
our software okay so let's look at the
connections that I've made um so
starting from the opposite and we have
the LED backlight display so as you can
see one is one pin is going to the
ground and you have a current limiting
resistance which then goes to the five
volts as I mentioned we have d4 to g7 so
those are going to be the data lines I
have them connected on pins 10 7 through
10 on my Arduino next we have the enable
pin which i've connected to pin 11 on
the arduino follow the rewrite in our in
my case i'm only going to write to the
LCD em i don't want to read any data
from it so i just have it grounded so it
permanently stand stays in the right
mode then we have the RS pin which is
going to pin 12 and this is used to
check the status of the LCD and at the
end here so i have a resistance placed
between the ground and v0 and as i told
you an easy way to do this is to have a
potentiometer but you may use a
resistance in in my case i've used the
same limiting current limiting resistor
so I believe it's 220 ohms and this
seems to work with the contrast really
well and finally we have power and
ground for the LCD so let's take a look
at the software which come which
actually comes with the Arduino library
all right so Arduino natively contains a
lot of libraries one of which is
providing support for the hd44780 or any
compatible with this algorithm so we can
simply start this library by first of
all including
so include liquid-crystal that h so this
includes the library into our program we
then define where our LCD is actually
connected so in my case it's 12 11 10 9
8 7 and I strongly suggest you go to the
Arduino website and actually see what
these pins are because I mean in my case
that's the RS enable and the 4 bits but
you can call this function a bit
differently if you want to get more
functionality such as read and write so
we're going to create the setup function
as always so here we're going to do an
LCD again so this enables our algorithm
so 16 - this is the size of the LCD so
it's 16 16 characters and two lines
we're going to do an LCD dot print so
here you can write any string that you
want so it's testing the LCD close the
brackets just for fun let's write on
auto scroll so the library provides a
lot of functions one of which is auto
scroll so what that means is when you
insert new characters at the beginning
of the line you're going to shift over
instead of sort of writing in a sequence
so you can make a square fact in our
loop so void loop as always
we are going to first of all set the so
obviously at this point we're just going
to output testing the LCD so nothing is
going to happen in order to auto scroll
we actually have to input some
characters so let's do an LCD set cursor
to 0 1 this sets the cursor to the
second line of the LCD since the first
one is called by a 0 so if you would if
you want to set your cursor at 0 0 that
would be top left corner of the LCD and
we're going to do an LCD dot print and
we're going to include a space this is
to set up the scrolling effect and we're
going to also introduce a delay of let's
say 300 milliseconds so this is going to
create a nice obviously not smooth
because this is a it has separate
characters on this LCD so you can't make
it a smooth transition but this is going
to be fairly nice so let's take a look
at what we've got on the screen and how
everything is outputting first of all
let's verify the sketch upload it
obviously now let's take a look at the
LCD alright so as you can see I've got
the code running and we can see the
testing the LCD message which we've
defined in our software scrolling so as
I wanted to show you this resistance
right for the contrast if I simply
remove this resistance you're not going
to see anything at all so it's very
important to have the correct contrast
setting and as you can see again remove
it and everything disappear so make sure
that you have a either a 20 to 50k
potentiometer here or you get the
correct resistance to actually see your
message what are the mistakes a lot of
people make is that they neglect this
contrast setting and they just do think
that you're not sending any message I'm
going to link to the arduino library
below and
if you want to find out more of what you
can do because you can get this message
scrolling left to right or right to left
you can change your cursors you can get
the LCD to blink you can you can do all
all kinds of fancy things with it so
please refer to that down below so I
hope you've learned something share your
LCD projects or what you're going to
implement this for make sure to comment
subscribe and let me know what else you
would like to learn as far as Arduino
programming goes thank you guys for
watching bye