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So welcome back.

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In order to start sending data we have to type out the data function the function that would set the

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proper register requirements in place to allow us to send data.

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So we would just write to her.

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It's very quick.

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Let's declare it for LCD data.

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Now this boy down here close to the LCD command.

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I'll just put it here.

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Void LCD on this court data.

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And just like the LCD command.

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This one takes one argument and this argument is not the type of assigned character we call it data

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and this data we want to write to the LCD.

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And we said in order to send data to the LCD we have to set the R S pin of the LCD to 1 in order to

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allow the internal shift registers of the LCD to choose the data register.

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So that's what we do here.

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You start by selecting the data register and all we have to do is write which puts a chip a data

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and don't let this confuse you GPA or a data and this data has nothing in common.

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The states are registered and we want to write to is in the internal.

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You know the internals of the LCD the LCD has two registers inside it has one for command and one for

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data and we select them and then we write command or select and write data.

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And this one here is the basic way of writing to a GPA or pots pin.

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We call it GPA or data.

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I hope you get the police whatever you do not understand.

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It in the comment box below.

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Thank you.

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So let's continue.

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So GPA or a data we write the value 0 x to 0 2.

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And basically what this means let me keep you young.

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Buying a reform the binary form is this serious you know 1 0 and 1 2 3 4.

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Yeah of course this is a 32 bit value or it's supposed to get 32 bit value all of these proceedings

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heroes can be cleaned and we can shorten a hair and it would work perfectly.

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That's why we keep on right here.

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That's why we don't write all the other numbers.

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So yeah.

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And what this means is our S which is the register select S equals 1 and naval pin Coursera and then

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our Coursera show remember our s Let's just check here.

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This is p a zero P A one two three.

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Keep it for a five when you check your physical connection your red lights that you connected to R S

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pinned to a five.

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That is why you've changed this p a five to one get called out to set it high to select the data register

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inside the LCD.

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So yeah.

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So once we select a data register we write our data and we do this by a sign in the IQ meant to this

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GPA or GPA or a data

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equals data.

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Basically it's this local variable data that we assign in her and after we do the Senate pass by enabling

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P E for a brief moment and what we do is to create a data today and a data then we thought this.

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Don't forget to do this.

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This vertical line and equal to it.

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If you don't put this vertical line and you write directly to it.

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Remember they are the same registered to share the same register.

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So when we write directly we change in all the values of the register.

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If we are to write without this line and then we just write 0 x.

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If we are to write just X sorry 0 x 8 0.

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If we had to write just this this one is going to happen like always.

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Let me break it down to binary for you.

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What is going to happen is we are going to have 1 0 0 1 2 3 4.

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And as you know a 0 a 1 8 2 8 3 8 4 8 5 6 7.

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So this the new value.

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But as you can see this fund to us has disabled this set and that we created earlier and we want to

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keep this in order to keep this.

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We do this.

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We use the all operator and we put a vertical line.

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So when we put this vertical line this father here this previous setting of the value is added to this

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one conclusion

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this previous setting is added like this.

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And an operation is performed when we perform.

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The answer becomes as you can guess it comes 1 0 1.

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Remember this one here and to say and then the rest of us to which serious you I've thought is why we

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bought this line.

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Also if you don't quite get this there is a course on the basics of embedded sea cortex programming

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which you can take a quick look at.

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It's explains these things in details and it makes programming really easy and robust.

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So that being said let's continue.

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We have this we've send the pulse and just like we did we delayed Michael delay 0 here which we can

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play wait or manipulate this file to her and finally we set it back to ISSUE super cheap or a data register

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because 2 x 0 0 and then then we delay again

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if we want.

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It's always good to be given bits of delay.

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Usually the best way is to give the minimum amount of delay as you go on to see how how well the microcontroller

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would catch up or how well the LCD will catch up put a microcontroller and then you start reducing the

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amount of delay gradually till it still works in order not to slow down the computer so you test you

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reduce the amount of delays gradually.

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So when we run it and it works we might need to reduce some of this delay amount and when the program

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still works which means it's fine.

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So now everything is set.

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We have to do now as typos are our data.

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So the first thing we do we have to clear the screen set the cursor home and remember we call the command

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to do this for us.

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Let's use this fiscal month as LC to command 2 x 2 1

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class to screen LCD command 0 x 0 8.

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This sets the coast home now.

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This queen is Claire.

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The curse I sent home and delay a bit just to allow these commands to finish executing.

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Okay good.

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How about we compile and see whether the compiler agrees with what we're 3 2 or one warning.

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It's probably because of no new line.

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It's probably down here.

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It should work.

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Or two warnings.

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Okay so the compiler agrees with what we've written that is great.

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So let's just put some basic data here.

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Remember data is transferred one character at a time.

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Do not worry I know that sounds a bit cumbersome to type one character at a time in the next lesson.

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I'll show you a function would engineer a function doubt allow us to type sentences at once.

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Let's play with our data and see.

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Basically I'm going to call the LC data

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how come we cannot see ahead.

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Where are you.

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Data show.

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The reason why LCD data is this way and we couldn't find it into help was because as you can guess we

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did not at to prototype up there.

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So just like we did for all the our functions as copies is and how to set function code to type now

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the only D stuff.

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This one here requires an argument I'm going to put on arguments here see like this and the function

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works so as great as I'm just going to try C M cortex.

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So as we said you can park your data with very very minimal delays to allow the LCD to catch up with

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the microcontroller show.

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I put a delay here and then I'll call the LCD data again and then write the second correct.

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Which is the end

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okay.

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This should work

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delay my could all that to go back to the top of the loop.

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Let's see so let's compile this and download onto a board and see what happens.

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Okay.

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Super errors two warnings

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OK it's downloaded.

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I hope you've downloaded all your board so please plug in your board download it and then reset your

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MCU the microcontroller to see what happens.

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So mine is in work.

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And I guess yours isn't working as well as a might be wrong given the speed at which we timed out this

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long code.

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My top mid said all mistyped something.

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Let's start from the top.

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There are prototypes looks like that in order.

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Let's see here.

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Okay let's increase this delay effort to millisecond.

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Okay.

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And then this come here.

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I suspect the arrow here goes nothing at all.

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Change is on the board.

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It has to be the initialization.

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Let's see the first one GPI.

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Oh this one here.

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This one here opens the clock for court.

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This one opens the clock for good.

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Aha.

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There is a problem here.

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Okay.

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How about we post the video and let's see what you can figure out what the problem is

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it's a simple one.

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As you can see we dealt with the same issue here.

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Remember when we got here and I was explained and I said if we write to this register directly by using

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just the equals sign we change in all the values of the register.

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So therefore when we get here and we write this new value we wouldn't have our R as selected.

156
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Therefore we have to use this.

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It's the same thing happened here.

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The RC GC GP registered the this registrar is the same but there are various bits inside to enable different

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GP I will pots.

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So what we did here was we anybody put a.

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And what we got here.

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We disabled poor and disabled put the what we want is to enable them both so we can just use the or

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operator to add this line here and then would enable it.

164
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So this problem is solved.

165
00:13:20,750 --> 00:13:26,240
Let's see what else we might have lingering around down there.

166
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Let's see.

167
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Aha.

168
00:13:28,980 --> 00:13:30,720
There is another one.

169
00:13:30,980 --> 00:13:32,660
Look at this line.

170
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This line looks okay but it is very problematic actually over here.

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00:13:39,620 --> 00:13:42,610
What we did was we selected.

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We made our eyes course to one using TPA or a course we connected our LCD control registers to the GP

173
00:13:53,150 --> 00:13:56,110
a sort of controlled registers are useful.

174
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Just selection only and the data registers are useful.

175
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Rights and data and data is in the form of command data and actual data.

176
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So when we write 0 x 0 1 which is 2 to enable this screen or to clear the screen this 0 0 1 is a form

177
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of data which is transmitted to the command register and we do it up by telling the LCD we want the

178
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command register active and then we transmit data to where.

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But what we did here was we use the.

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I should also point out that we use the arm that paints the data pins d you go through a D7 to transmit

181
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in a form of data without the data is actual data or its command data.

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We use these pins but we made the mistake of trying to write data to the control the control parts with

183
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it which is GP 8 or a actually it should be GPA.

184
00:14:58,430 --> 00:15:01,350
This is how data is transmitted.

185
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Course we've connected our 8 bits of data line to put to put B.

186
00:15:07,760 --> 00:15:10,040
So let's recap what we just did.

187
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So we came here.

188
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We selected we selected the the LCD data register and we did this by set an R as 2 1 and then we wrote

189
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data we put data into data bus and basically we make GPA will be our data bus and then we put our data

190
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there so I know what might seem confusing as we're using the named data and command.

191
00:15:35,690 --> 00:15:39,340
Meanwhile command actually is a type of data.

192
00:15:39,920 --> 00:15:47,380
So the same thing is affecting this function that we wrote over here we selected our hero.

193
00:15:47,390 --> 00:15:51,080
The only difference between this and this should be are you actually.

194
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So we selected our zero and we have to write a command to it.

195
00:15:56,120 --> 00:16:03,470
And remember this command also has to be put in the database and sent to the command register inside

196
00:16:03,640 --> 00:16:11,510
our Su and we designated codes B I saw one data bus but we forgot we got excited and kept typing and

197
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typing.

198
00:16:12,650 --> 00:16:20,180
So yeah this line here should be GPA would be data and this line should be data anyway.

199
00:16:20,180 --> 00:16:20,820
Yeah.

200
00:16:20,960 --> 00:16:25,100
If anything this error has taught us to pay more attention.

201
00:16:25,310 --> 00:16:32,810
And one last thing I realized right now was we said we have to senate pass through P E while we did

202
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it.

203
00:16:32,960 --> 00:16:38,510
We enabled and didn't disable it mean meaning we did not actually senate pass through it.

204
00:16:38,540 --> 00:16:46,400
We kept it enabled in order to send a oppose would just enable and disable very briefly and we do this

205
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by setting this data register back to 0 x 0 0 and everything should work perfectly.

206
00:16:54,980 --> 00:17:00,020
Now let's compile and let the compiler judge.

207
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Okay so white is working as you can see it's working

208
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and the potential for me to adjust in the contrast is this little one I have heard by turning it contrast

209
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changes.

210
00:17:21,000 --> 00:17:21,700
Yeah.

211
00:17:22,120 --> 00:17:26,440
All we have to do is play with a bulb used in the arm in the data.

212
00:17:26,440 --> 00:17:33,700
Let's try to extend the amount of data we transmit and try to play around with and delay values a bit.

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Yeah so see you in the next lesson.