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Hello.

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Welcome back.

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So in this lesson we going to ride the SS I driver to interface a Texas Instruments and force you one

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two three microcontroller with the SD 7 7 3 5 graphic liquid crystal display which is a colored LCD

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screen for displaying graphics so I'm going to create a new project by coming over here.

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Project your vision project

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and I'm going to come over here.

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Create a new format for this

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I'll say Tim for C 1 2 3 SD 7 7 3 5.

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Driver Not quite a project.

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S t 7 7 3 5.

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Driver

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and the microcontroller is for C 1 2 3 0 8 6 p.m..

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Select this over here.

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Okay and the census isolate the core

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on the device select the startup with this device or select startup

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click okay here and I'm going to come over here Target's options

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using distilleries I CDI setters reset and run.

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Okay and then okay.

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Right click here.

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Target system for C T 4C one two three.

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So this group here renamed to up

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and in this project we actually are going to make it a bit more interesting by also initialize in an

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ADC driver so that we can connect a potential meter to our microcontroller board and plot the resistance

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as we turn the potential meters knob.

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We will be able to plot how the default age changes on the LCD just for a test.

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So I'm going to create a separate file for the LCD driver.

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So come over here and.

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I call this

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g LCD

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SD 7 7 3 5

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and then I'm going to copy this name because I'm going to create the header file as well.

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Right click right click each new item this ahead of file and it's going to be called this and I'm going

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to create the main file right click that new item.

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This is going to be made at C

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OK.

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So we start with the driver file.

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This one here too we basically going to create a number of functions for initializing the LCD.

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And what we're going to use here is going to be information from the the SD 7 7 3 5 data sheet the data

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she talks about the various steps that needs to be taken in order to configure the LCD screen as well

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as you know right data to it.

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Right.

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So let's start by including some symbolic names to are what drive here.

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First of all list included the head of file of the microcontroller.

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This is it.

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Once that is done I'm going to if not define defined in this interface file

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then.

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And if over here

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right now I'm going to include some symbolic names.

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So these are names representing the setting of certain bits.

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So it's in the control register 0 as well as the control register 1.

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We're going to give all of these bit symbolic names to that rather than type the hexadecimal numbers

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we just call the symbolic name.

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And this is going to make the code more readable.

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Right.

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So this over here sets SS asynchronous serial port.

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This represents this hexadecimal code and it's the same for all of them.

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So that will reduce you know calculating what X hexadecimal code we need to pass to the register we

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just call these symbolic names.

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Once this is done there's one more I would have to include the busy bit

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and Hubble will include one for the day transmits five or not for this is simply 0 0 2 we can give it

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a symbolic name as well.

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So we call an SSI status register TANF a simple cluster.

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Once that is done we're going to add we're going to add more defined statement

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and this this year is for the D.C. line.

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As you can see on the MCU there is a line known as the DC line.

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And this over here if we want to set a DC line high we pass this and then come mode would pass zero

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data mode would pass through x 4 0

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this year.

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As for the DC line the address of the DC line.

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And if we want to set a DC line to command what we pass through to data would pass through x force 0.

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That is a.

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And just as a reminder I'm going to bring the pin out here to remind us to remind us of what we're dealing

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with.

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So the DC is connected to p. 86.

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That is why to set the data mode we set in this 2 4 0 0 x 4 0.

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Because if I explained this to it's binary form you realize that bit bit 7 which is bits Number Six

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because we count from 0 but 7 is set to 1.

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If you expand this to accept it that if you expand this to its binary form you realize the bits number

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six which is the seventh bit is set to 1 because we counter a 1 2 3 4 5 6.

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Right.

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I'm going to suffer a bit and the reset line is connected to pierce 7 okay.

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So that's what we're dealing with.

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Once that is done we can define our LCD board over here.

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Create a symbolic name for that as well to improve readability.

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I'm going to connect the LCD to put a

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and then again when I put some other defined statement for the arrest pin which is P seven addresses

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reset CSP and which is P A three.

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So I'm just using bits shift here and then DC pin which is P6 right.

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So of course symbolic names for these as well.

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Once that is done I'm going to create a symbolic name for it for setting RSP in to 0 setting RSP into

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one set and see esp into 0 setting it to 1 set in DCP into 0 and setting it to 1.

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So when you have a symbolic name for that as well and I'm just gonna put these names here.

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So if I simply call LCD R S 0 screen to set p a 7 2 0 2 if I call LCD R.S. one is going to set p a 7

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to 1 and it's because we've written it this way.

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So when we call the symbolic name this code is executed and it's the same for the rest.

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Once that is done we're going to put some constant here with regards to the parameters of our LCD the

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width of the LCD is one hundred and twenty eight pixels and the height is 160 pixels.

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So I'm just going to create defined statement for these as well.

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When I put them here like this once that is done we are going to define certain colors.

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We can define colors as what colors are simply hexadecimal numbers like any other two.

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I've got some colors that are already defined.

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I'm just going to bring them as well.

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Here are the colors right.

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And once that is done some specific registers in the LCD.

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When you take a look at the data sheet there is the R is set to register C it sets register and other

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other locations in the LCD memory map and we're going to create defined statements to navigate this

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locations.

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These allocations in indeed OCD so there are other constants with regards to the LCD there is the art

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is set which according to the data sheet is 0 x to be there is the C is at whose address is zero x to

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a will be integrate define statement for D as well so that we can just call the symbolic names rather

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than run it and end up with a code filled with hexadecimal numbers.

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We don't want that.

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That is why we are doing this.

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So since we said we are going to be plotting graphs I've created a symbolic name for certain parameters

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of the graph such as the background color of the graph.

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The Axis color the background color and other things so I just I've just given them symbolic color names

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because we've created a color names here.

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So I just bring these deaths including the command for setting the display on and other things.

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I just bring this here and we're going to use all of these in the c file.

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That's one put in here so that as we type in the CFR we just don't see red marks because these symbolic

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needs to know exist.

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Once that is done in order to type text we need to have a font.

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We need to include a font.

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So I've generated this font and fonts are generally generated there are different types of font so it

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is just a long array of numbers of new 8 numbers.

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And that is how you get the font on the LCD screen so this font and these numbers represent 0 to 9 ABC.

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All the characters or the symbols.

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Question mark comma harsh.

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All of it is represented in this in this array.

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So this the format and simply calling it font over here.

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The reason we have this error is because we've not included sd d and so I'll come over here and include

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it

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and it's disappeared.

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Right.

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So now that we've sorted this out let's go to our implementation file which is they don't see file and

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start writing out the functions

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so we're going to need a delay function cause during the initialization process where we set certain

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bits we've got to wait for some time before we move on.

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Cos of that I'm going to bring this time of function here like this.

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And the reason I'm bringing this time a function without write in is because we've already learned how

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to write such time of functions in the time section so I know you would understand what is going on

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here.

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The reason we have these marks is because we don't have access to these microcontroller specific structures.

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So all I need to do is include the DOT h file because we've already included temp for C dot h here.

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So I'm gonna include a dot h file here.

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Our problem should be solved right.

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Once this is done I'm going to create a function called SS I 0 in it so I'll save for it SS I 0 on the

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score in it and this takes no argument open closed.

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So I'm going to start off

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I'm going to start off by actually bringing in some more I'll create some local create some local global

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share some global variables global only 2 the dot c 5 million.

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We cannot fetch them outside this far but any function in this file can fetch them and I'll just bring

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them here.

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This includes setting the width and height of the LCD which we've already defined in a dot.

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Each file we defined this we defined this as well we set in start X to 0 starts way to 0 and we have

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columns that's real estate and text color to 0.

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We've just set these goals we're going to need them right.

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So once that is done I'm going to initialize the column start and the row starts as well as create a

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new variable called delay like this.

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And once that is done I'm going to enable clock access to the SS II module as well as the keep your

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module that we've connected the SS to and I'm going to come here and do this like this and this line

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here is just to make sure that the initialization is complete before we move on to the to the next line

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of code.

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So there's just a blocking statement to make sure that we've completed executing these two lines before

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we can move on.

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So this just a poor.

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This can be admitted.

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Yeah there's nothing wrong with it.

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Once that is done I'm going to go to GPL you a and access the direction register and set the pace that

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we need

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setting them US UP BRING OUR HEAD a file here.

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This should assist the

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some of the things that we're using put this yes.

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Well as a reminder and then I'll set the alternate function the alternate function is set and then digitally

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enabled them

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once that's done.

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I coached at Port controller register

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and then inserted.

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Then once that is done or disable analog so let

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once that is done I'm going to set the C S line to 0 and then the address line to 1.

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Remember we already created symbolic names for C S 0 and R S 1

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and according to the data sheet when we set CSU to arrest one we've got to wait for a bit and then we

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set our best to 0 and then wait for a bit and then sets out as to 1.

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So we've got to follow that initialization sequence.

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So I'm going to wait for 500 EMIs once that is done.

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I'm going to set R S to 0.

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We already have a symbolic name for set in r s to 0 as well.

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So once that is done I'm going to wait for another 500 m s

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and then set R Us to 1

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and then

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wait for another 500 m s once we've done this.

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We go ahead to initialize the SSI module

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right.

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So we set up these and then we disable the SSA module by access the contra register one and using the

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enable pin that we have here because we've already created this symbolic name for this and then will

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select master mode.

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We've already created a symbolic name for Master mode as well.

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You can find all of these in these that each these defined a statement we have here.

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Once that's done we configure for system clock and the bot rate source and all of this is making use

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of the defined statement we wrote earlier.

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And to learn more about any of these registers you can simply go to the data sheet find the SSI readable

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these registers.

204
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The reason in the beginning I spent so much time taking you to the data sheet to help you navigate and

205
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find various registers and how to read the the the bits and decode the meaning of each bit set in so

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that I can move faster in the later sections such as this one so that I can simply use a register and

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tell you this is the register required and knowing that you can go to the data sheet on your own as

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an independent and better developer to be able to locate these registers and read more about them and

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understand or should you be confused as to why you know for instance as to why we set and see are one

210
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we set it to less is we set in bits one to one if you don't understand that you simply need to go to

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SS a section in the data sheet find a C R1 control register 1 and then check bit 1 and see if between

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is 0 What happens if between is 1 what happens by finding that out you simply understand everything

213
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should you be confused right

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if you have any questions of course you can send me a message

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right.

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So this is going to be our SSA in its function but we have to include further code here for some initialization

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code months across the data.

218
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She talks about setting common sequence that you need to execute during initialization and write it

219
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an item to this function we go into create a separate function to sort out that that task

220
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right.

221
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So let's just without an order not to forget it.

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Let's write it here.

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So I'm going to call this new function.

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Void standard in its command or you can give it whichever name you want.

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And according to the data sheet to initialize we start off by set in the C S line our baseline to 0.

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We wait for around 10 milliseconds said the errors line to 1 and then would write command we write a

227
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specific command and then we go on from there.

228
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So we start off by setting C s2 0 arrest 0

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we wait for 10 m s and then we set our rest to 1 we wait for another 10 m s and then we write the commands

230
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0 x 1 1 2.

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I'm going to bring this here.

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So this should tell you that we need to write a function that would help us write commands.

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We currently don't have this function.

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That is why we have this red mark.

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We should write this function after this wonder we are currently dealing with we radical monster x 1

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1.

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We wait a bit longer this time let's say we wait for 120 milliseconds.

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Once that is done we write the command to set the color to sets the bids.

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And finally we set a display.

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And just like the datasheet of the of the microcontroller if there's a specific hexadecimal command

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you do not understand.

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You can find this in the data sheet of the LCD the SD 7 7 3 5 LCD.

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These commands and the Armenian is written in there right.

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And one other thickness.

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This course is going to be is going to be mostly about dealing with the LCD at this point.

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Really.

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We are done with initialize and the SBA or the SSA module.

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That's the thing with SSI.

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It's initialization is so simple and straightforward.

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Majority of the time you spend customizing functions for communicating with a particular SSI slave.

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In this case the rest of the course is going to be spent or the rest of this particular lesson is going

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to be spent on writing functions to sort of navigate it configure and write data to the LCD screen taken

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into account or or using the information provided in the LCD data sheet.

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So that's what we are doing though right.

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So because of that some of the functions I'm just going to gloss over because this is not a lesson on

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this particular graphically liquid crystal display.

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It's a lesson on SBI just that it will be interesting to show you how it works with a real world slave.

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That is where we have this LCD here.

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Okay so once this is done we still have this function to sort out.

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We have two functions here one for writing code on one for writing data.

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Command is different from data.

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Data is where you want to be sort of printed on the screen.

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Command is sent to the screen to configure it such as configured the color mode configure the bid size

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turn on the LCD sets the cursor etc..

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So that is why we would have two functions one for command another one for data.

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So less rights the function for writing commands.